IROCZman15

iTrader: (25)

Ok guys, I apologize if this seems long, but I find that it is better for me to lay out as much information as I can instead of back-and-forth question answers.



1987 Camaro IROC-Z TPI setup

with external coil. Stock distributor. MSD cap/rotor. MSD external coil. MSD Digital 6 ignition CD box. this setup has been on the car for about 4 years, and the car has been very good with it. until something strange and WILD happened recently
-None of the wiring has been hacked or is mysterious. I have owned the car for 19 years and things are very orderly under the hood.



I defintely searched and read about 30-40 threads regarding the NO START issue I am having. Also this tutorial: https://easyautodiagnostics.com/gm/4...ed-icm-tests-1

I have developed a decent understanding of how our HEI ignition system functions, but I have some unanswered questions because I can not determine what the heck is going on with my particular no-start issue. Many others have had success testing volts and ohms at the external ignition coil, and the pickup coil, and also the ignition module. As per the tests I have done on these components, my parts are all still good. I am unsure if I am now dealing with an Ecm or distributor issue. The main aspect of my situation that is different than ANY other “no-start” thread I have read, is that I found a melted/burnt rotor and distributor cap. I can’t determine is this is the “cause”of my issues or if it is the “result” of the underlying “no spark” I have happening.



I drive the car a few thousand miles a year and from March-November I had zero issues with it running. Come November, one day while driving it died on me…just cut off while I was doing 40mph. pulled over, after 10 mins or so it came back to life. Figured something was loose and checked it over when I got home. Nothing was observed. More normal driving for a few weeks. Then in early December after the car had been driven 45 mins and left to sit for 2 hours. It wouldn’t start. I did the usual fuel pressure test and fiddled with the coil and my MSD Digital 6 box. Again, after 15 mins it fired up and I drove to work and then home. Drove locally a bit and it stalled on one other occasion. No sputtering or coughing, it just went off. My mind thought “ignition issue” so I put the car away (engine ran fine) for the winter knowing I had to examine all the ignition components and fuel system. After installing my new Moser 12 bolt last week it was time to look into the engine issues. Went to start the car on Sunday, and no-start. It is absolutely not a fuel issue. I have fuel pressure and can hear my 340lph pump running and flowing fuel through the lines. (It runs for a good 5-8 seconds after I cease trying to crank the engine over. I hear it refilling the tank. It is an aftermarket Racetronix system I buiilt last year with a 340lph pump and the upgraded in/out of tank wiring kit.) Pulled a few plugs out and they seem wet. Can smell fuel too. I will put in all new plugs, but only once I solve the overall issue…no need to foul out new ones now. Noticed that I am definitely NOT getting spark to the plugs.. therefore checked back at the cap/rotor. When I went to pull off the center coil wire on the cap, it tore off the melted post from the cap. A big WTF moment there; I saw black marks and melted plastic. I removed the cap, and found a melted center terminal and the melted rotor. See photos.

I went online and read that this can be caused by moisture under the cap, etc. Our distributors have two screened vent holes at the base, but I figured it was a possibility…welp, now I know that I need a new cap and rotor, so I ordered a MSD replacement from Summit and installed it yesterday, thinking this had to have been the “cause” of my stalling/no spark issues in the fall. I also bent up the metal tang on the rotor a slight bit to ensure thre was no gap between the rotor and the center button on the cap. Sadly, I still had no spark. I then checked my MSD external coil for spark at the terminal. None. I then removed it and did the OHM testing on my bench. All values were in line with what TGO, my GM shop manual, and my hanes manual say they should be. Just for the heck of it I got out my old OEM external coil and put that in place after OHM testing it and getting proper values. No spark. I unplugged my MSD digital6 iginition box and the adapter wiring harness that is used with our external coils, and routed all the wiring as stock would be… to both the oem and msd coils, and neither would spark.



Began searching here on TGO and in my GM shop manual. I had replaced my ignition module about 8 years ago when it quit on me so I thought it was that. I removed mine and brought it to Autozone where they tested it 3 times in a row on their machine. It passed all 3 times. I had them test another one on their parts shelf and it passed also. I bought it anyways and decided to put it in (both with the supplued thermo paste yes. Cranks, but no start still. The rotor is turning around on the distributor also.



Next, I ohm tested the 2 wire setup (fat wires) pink and white that are on the grey plug at the coil. I removed it from the car and ohm tested each wire … getting 0.00 resistance. Ok good. So my wiring is good there. I plugged the grey end of the connector in along with the black one next to it, and tested the other end where the pink wire ends (at the + pin where it would conect to the ignition module) and got 12.16 volts. So I am getting 12.61 volts to the ignition coil. Next, thinking the pick-up coil could be busted from all the chaos that happened inside the cap when the cap/rotor melted, I ohm tested it…gettign a reading of 9.11 M ohms ..which seems proper because I read it should be between 800-1000 ohms right? I then connected my multimeter using the volts AC setting at the pickup coil and got 2.53 voltsAC while cranking. So am I correct in thinking that my pickup coil/distributor is OK?? or am I missing something there?



Other tests I did the next day(today), some repeated: (keep in mind my battery was charged but got lower the longer I tested and cranked)

With KeyON-EngineOff I connected the multimeter to the smaller pink wire (on black connector at coil) which is power To the ignition module) and to the negative battery terminal and got a 11.69 VoltsDC reading.

The large white wire on grey connector (tach circuit) goes a few inches and then to a plastic factory conector, then it disappears into the main harness loom and I assume just goes to the tachometer. This shouldn’t (or wouldn’t?) effect spark right? It is just to display rpms on my dashboard right?? I have read that if it is shorted, it “could pull down refrence pulses to the coil” ??? interesting



I have used tiny picks ad dental tools to re-bend some of the metal harness connections to ensure that they are making contact with their respective plugs/components. Very delicately…. ….Yet, All of this plugging and unplugging of conectors has resulted in two snap-lock clips being broken, but I am sure that good electrical connections are still bein made. I will have to find a way to secure the connections…once the issue is soved though.



I have read that the ignition control module should be getting 5 volts from the PCM? I unplugged the 4 pin connector that goes into the ignition module and tried to ohm test the ground wire by using a multimeter and touching one end to the black wire’s pin coming from the wiring harness…and the other to unpainted chassis bolts on the strut tower. I got 50K ohms ??? another time I got OL open line. At the tan wire I got 2Mvolts. At the ppl/white I got 117 Mvolts. At the white wire I got 48 Mvolts. This is supposed to be the EST wire right? I also tested this with my test-light and got NO light at the test light. I actually tested all 4 pins on this connector here and none of them got the test light flickering. All of these tests were with the Key on, engine cranking, all other connections were in place



Another test I did was I plugged only the grey connector into the external coil and used a test light at both holes where the black connector would go (small pnk and small white) and it lit up both times. I then plugged it in and tested it at the other end where it would plug into the ignition module.



I don’t know how to test for switching signals, or how to test that the signal is interrupted?





So, as it stands, I am stumped. Somehow something caused my cap and rotor to melt. I think that this was the result of something else failing, but I can not determine what. If you guys agree that my tests above are Ok, then I am totally stumped and don’t know what else to do. If the pickup coil tests are ok, that means my distributor is ok right?? But what if it is my ECM that took a dump. Would it melt a coil like that? What if it somehow wasn’t grounded fully or had a short ? From what I can tell from the book, the ECM grounds to the bolt that comes off of the back of the drivers side cylinder head right? I have ground wires tehre, they are all connected, but the wire insualtion has seen better days. Its super tight back there and I am afraid that if I try to clip the existing ring terminal off, I wont have enough room to put a new ring terminal on with shrink wrap etc. its super tight. Could I re-ground the ECM to somehere else instead, or even add a secondary ground? What kind of problems would that cause?



Thank you guys in advance. Please post ANYTHING you think can help.



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DynoDave43

iTrader: (11)

LB9GTA

iTrader: (1)

I had the same thing happen at the track.
Turned out that my msd digital 6+ box gave a voltage spike and melted the middle terminal on the cap.

The msd box was fried, sent it back, along with a new cap and rotor and go to go

IROCZman15

iTrader: (25)

hmm very interesting. cool thank.s however, I keep trying the tests and cranking over with both the OEM stock wiring setup (MSD unplugged) and also with the MSD digital6 wired and plugged in .. (however most tests are done with OEM wiring combination since there are less components for me to deal with though). red light on the box is solid with key on.
--new cap and rotor are on and I was truly hoping that was going to be all that was needed. I am very concerned now that it got this deep and involved

the other odd thing is that the car ran the day it was parked in early december and sat with the hood closed until just this week.

NoEmissions84TA

iTrader: (1)

Pickup coil - you said I ohm tested it…getting a reading of 9.11 M ohms ..which seems proper because I read it should be between 800-1000 ohms right?
9.11 MEG ohms is nowhere even close to 900 ohms. Typo maybe? If it actually is 9 MEG ohms, that pickup coil is NG.

Cheap rotors of that style sometimes develop a short right through the plastic to the mounting post on the distributor shaft. You would need an eye loupe to see it.
But yours is new, so that is not your problem. Worth a mention, though. When it happens, the car acts exactly as you described - cuts off randomly and will restart after some time with no real explanation.

You said you removed all the MSD stuff to put it back to stock and still no spark. I suspect that pickup coil at this point. But you got ac voltage while cranking - I then connected my multimeter using the volts AC setting at the pickup coil and got 2.53 volts AC while cranking. The new distributor has a new pickup coil correct? Swap the components back and try it.

GeneralDisorder

iTrader: (1)

Was about to post that....

I would like to add that in cases like this where things are burnt/melted it is important not to trust a typical dvom for voltage readings - you need to either do a voltage drop test or use an incandescent test light to prove it not only has voltage, but can carry enough current to be useful.

GD

IROCZman15

iTrader: (25)

GeneralDisorder

iTrader: (1)

On your meter there - hit that RANGE button and take it off of Auto mode. You want it in "K ohms" mode (that's thousands of ohms), and then a good reading for the pickup coil (given your spec) would read 0.9 to 1.0

Given the readings you are taking there, it will probably show "OL" which means "Open Line", or some meters will shows "^^^^" or an infinity symbol. Whatever it shows when you aren't connecting anything at all to the leads.....

GD

IROCZman15

iTrader: (25)

ah, goooood point. I gotcha. gotta adjust the range for a more accurate ohm reading. my mistake.
will do so tomorrow and report back

as it stands now, I am thankful to know that the pickup is probably the culprit. I have been talking to Scooter a LOT in text messages and I eternally grateful for his help and for everyone's help on here as well. Thank you all

As I understand the system, there is no way the no-spark issue could be related to my PCM/ECM at all... because that doesn't get involved in "spark" at all until the engine is actually running and is over 400rpms...correct? I just want to totally rule out any computer issue, or bad grounding issue involving the computer. thoughts? anything else I can/should be checking regarding the computer? rent a noid light and check for injector pulse ?

I also quickly checked today,and while cranking, I can see the tach on the dash moving a bit. this is good. I am hoping this means that I have no interference backfeeding the ignition pulse.. correct?

lastly, that brings me to the pickup coil. if I test it again tomorrow (using the proper ohm range) and get OL openline or anything outside of the suggested 800 - 1000 ohms (when green and white wires are both probed at same time), then I can rest assured that the pickup is bad. despite me getting an OK reading of AC when cranking and checking the pickup?

I already have a known good ignition module (plus the one I plan on returning to autozone), a new cap, and new rotor... so It might make more sense for me to just buy a pickup coil right? instead of buying an entire distributor? Scooter offered to let me borrow an old distributor he has for a bit. I might do that next, but first might instead buy a pickup coil and replace the probable bad one on my current setup.

any recommendations on specific pickup coils to use ....or ones to avoid?
- I read posts here on TGO about using the Delco parts? I think this would be it??
https://www.autozone.com/ignition-tune-up-and-routine-maintenance/pick-up-coil/acdelco-pick-up-coil/918278_0_0?&searchText=d1907x
or any of these?
https://shop.advanceautoparts.com/web/PartSearchCmd?storeId=10151&catalogId=10051&pageId=partTypeList&suggestion=&actionSrc=Form&langId=-1&searchTerm=pickup&filterValue=vehicleL4CatNameIdFacet:%227915%7CIgnition%20Pickup%2FStator%7C-49999406%22&vehicleIdSearch=7915&filterValue=isFitted:1&beginIndex=0&sortBy=4&_r=0.13572482845994438&doExactFit=false



I also will order a new harness wire https://www.ebay.com/itm/GM-TPI-TBI-...LCRQ:rk:9:pf:0 in the meantime.

IROCZman15

iTrader: (25)

sofakingdom

iTrader: (1)

The Delco pickup coil is fine. Might even be made by Delco, and possibly even the same as the OE, but not necessarily. Doesn't too much matter though. One made by any of the OEM-grade mfrs - Bosch or Nippondenso for example - should be fine as well. It's also not impossible that a Delco boxed part came from some other mfr but they just put it in their box, although not as likely for a part that fits a GM car as it would be if you bought a Delco brand part for, say, a BMW.

The burned up cap & rotor look like your plug gap was too wide. Stick with the .040" - .045" kind of range. The insulation in the rest of the system can't withstand the voltages that can build up with a high-power ignition system and the spark being forced to try to jump across a really large gap. Anything over about .060" is almost certain to cause failure. The energy of the spark will always try to find the path of least resistance on its way to ground. And if that weak point happens to be through the center of the rotor to the top of the dist shaft, then … the result will look exactly like what happened there.

GeneralDisorder

iTrader: (1)

Yeah I second that - get the Delco pickup coil. Your coil is definitely toast if there was no connection between the leads on the K Ohm scale.

And Sofa is correct about the plug gap - the gap (and cylinder pressure) DIRECTLY impacts the ignition coil secondary voltage. The coil MUST build voltage till that voltage overcomes the resistance of the air molecules between the gap (more pressure = more molecules, and more gap = more molecules). Too many molecules = too much voltage = breakdown of the weakest point of insulation in the ignition system. Just like everything is flammable (and inflammable!) if it is hot enough - everything is a conductor if the voltage is high enough.

GD

IROCZman15

iTrader: (25)

thanks fellas I just ordered that AC delco pick-up coil. it should be here by the weekend and i will install it then.
this one https://www.autozone.com/ignition-tu...oil/918278_0_0


as for the plug gap. that all makes sense. however, the plugs are all gapped at .035. also, they are two heat ranges colder than stock plugs due to occasional nitrous use. when I pulled a few of them out the other day to check and see if I was getting fuel spraying into the cylinders, the gap was spot on .035. I actually checked it on two of them as I was wiping them clean. new ones will be going in this weekend once(if) the pickup coil solves the ignition issue. should I bump the gap from .035 to .040 ? prior to the no-start issue and the cutting out randomly, the engine ran strong and was has been that way for several years.. gap has been .035 for at least 10 years on all my plugs. .

From reading about burned up cap/rotor/buttons on some other sites, people say a likely cause could have been that the button on the underside of the cap somehow got stuck in an up position causing an air gap between the rotor and it. ? or the tang on top of the rotor was not making solid contact with the button because it got bent down? I know also my msd digital6 throws a lot of juice at the ignition system, too.
however? is there a chance that the failing pickup coil caused any of the melted cap and rotor though? from what i've recently learned, once the pickup fails, its usually dead forever.... not an intermittent or occasional failing. so my thoughts are it was just bizarre timing and bad luck that the pickup failed when i put the car away in December and i just noticed it now? the cutting off/stalling out issues were caused by the melted/melting cap/rotor and are a separate problem. ? possible ? likely? ---OR---- did the problem with the cap/rotor melting cause the pickup to fail ? which chain-of-events would make sense. I like to learn, and would certainly like to avoid this situation happening in the future...

lastly, I can still completely rule out any type of computer/pcm failure from this ignition issue right? I think so, but just wanted to ask the pros.

IROCZman15

iTrader: (25)

well, the pickup coil I bought (mentioned above) wouldn't work. the connector was too large to fit on to my ignition module. thought about taking the connector off and using my existing plastic connector instead but tried a different one at autozone (can supply part numbers later) and the connector was proper, but the pickup coil had a different top plate on it, and research showed it would not work (for large cap 1986 dist) . I ended up buying the $9 plastic inner portion of the pickup coil .. it has the two wires (white/green) on it and the proper plastic connector. I ohm tested it and it was perfectly in range at 758 ohms . pulled out the distributor and took it apart. had to remove the top magnet (with the 8 triangles on it) that makes up the hall sensor. put the new one in and reassembled the distributor. put that back in the car along with the ignition module, ignition coil, cap, rotor, wires etc. checked for spark with a test light at the remote coil. got sign of a spark. plugged in the fuel pump fuse, and fired the car up. ran rough at first.. probably due to fouled plugs from all the attempts starting it the past few days. ran the car for a few sessions, totaling about 10 mins run time over the course of an hour. this was all with the stock wiring configuration (no Msd digital 6 box).

came out the next day and tried to fire it up. it sputtered and ran for a few seconds before dying. tested each component and long story short, removed the distributor again... i could see that the teeth on the distributor/rotor shaft were now ever so slightly making contact with the teeth on the hall sensor of the pickup coil. ?!?! I have no idea how this would happen, but it was not this way the day before when I installed it. it spun free, I am certain of that. so I pulled it all apart and did some very slight hand-bending to gain clearance. put it all back together. it ran again, but a little dirty. i had 8 new spark plugs to put in that I already pre-gapped at .035 . put those in. it ran much better. next I swapped just a few wires to hookup the msd box.. and the car wont run. I can see that I have "signal" for spark coming from it, because when I put a test light onto the orange wire (what would normally be the small pink wire of the black connector on ignition coil) it lights up the test light a few times per second. ohm tested the ignition coil again. all was good (it should be because this is the same exact ignition coil I had powering the car just an hour earlier..it was not swapped). so that I can't figure out.?? why the remote ignition coil will work with the stock wiring configuration, but not with the msd box that is giving it signal to spark??. I will have to call MSD on monday.

I have the battery disconnected tonight to clear codes out. was getting a code 42 while it was running today. will be checking over things again tomorrow afternoon. when putting in the distributor I got it right on the marks I made, so i did not bother to disconnect the est wire and set timing with a timing light. I have no problem doing so, but since I got the marks correct, I didn't think I would need to??

definitely not giving up, but getting frustrated about all this. hoping to have a reliable working ignition system within a few weeks to start driving the car again. would really like to not be nervous about driving it anywhere any time I plan on taking it out.

IROCZman15

iTrader: (25)

!!!!!!!!!!!!!!!!!!!!!!!!!!! had the car running today. decided to check the timing and I was a few degrees advanced so I adjusted it to 6deg advanced and let the car run for a while. turned it on and off a few times over the course of 30 mins.

came back 2 hours later after returning the unused ignition module and unused pickup coils to autozone for a refund. car wont start!. !!!! checked for spark at the ignition coil wire using a test light.. and no spark. what in the HECK is going on here. I am getting definitely frustrated with this now at this point. components work and then decide not to work a short time later? nothing changed at all from the time it was running till 2 hours later and now no-go? unbelievable !

if anyone has any thoughts, please let me know.

GeneralDisorder

iTrader: (1)

Don't buy Autozone parts. This is the predictable outcome. Call these guys:

https://performancedistributors.com

Unfortunately even "AC Delco" doesn't always mean it's quality stuff. And it sounds like you have some kind of cascade failure going on. If it were me I would replace the whole distributor, coil, plugs and wires.

GD

NoEmissions84TA

iTrader: (1)

Your car is possessed.

IROCZman15

iTrader: (25)

thanks fellas. I am going to keep at it for sure.




I'll be ordering a distributor today and removing the oem one that contains the new $9 pickup coil and known good/tested Ignition module. Ill keep it off to the side and see what the new distributor does. I didn't like how it seemed that there was interference/touching of the contact points in the hall-effect sensor the second time I removed the distributor. I am certain that the rotor assembly spun free prior to me installing it, but then the next day when I checked it there was definitely touching of the triangle magnet points. It seems the metal cup/housing that the pickup sits in is old and sloppy and doesn't like to sit perfectly flat on the top of the distributor shaft. there is a small pin that holds it down and i tried to re-seat it, but it didn't do much at all. I am wondering if the sloppyness in this cup causes the hall effect system to intermittently work/not-work. seems like it would. I'll order a new distributor. any recommendations? I do appreciate the advice on the performance dist link, but s there anything else recommend for simple ignition setup that I could just get this thing running and driving for another 9 months/3,000 miles before the whole engine comes out for good? id rather not spend the $280 for this one https://performancedistributors.com/...-distributors/ just to find out the distributor was not the cause of any of my problems. any specific one you recommend ?

I will be removing the MSD cap (new distributor will come with one anyways), along with the MSD ignition coil even though it tested good. I will put my stock OEM ignition coil back in. I will try to find a new grey connector for it too since the locking clip part broke off during all my recent troubleshooting. I guess I could find one on ebay??, cut the large pink and large white wires and splice them onto the new connector end? I already bought a new wire that has a nice new black clip on it and the other end connects to the ignition module. I ohm tested that too and it is good. the old one had a broken locking clip. the last clip that got busted was the 4 pin one from the ignition module to the harness/est/ecm i'll try to find that also. that one will be tougher to do replacement since it is behind the valve cover in a tight spot and has 4 wires. but I do want to make sure that the clip/connector is fully seated and wont rattle free as I am driving down the road. I just want everything to be setup properly , working properly, and no longer a worry.. just for these last 9 months that the engine has left in this car.

at this point I don't think I need to worry about CODE 42 because I think that is the result of the ignition problems and not starting occasionally..?. code 42 is for the EST so that would display as a result of the stalling/not starting right? that is a "result" not a "cause"? or is it something I should dig deeper into now?

GeneralDisorder

iTrader: (1)

You won't be using the distributor on the next engine? You could always sell it to recover some of the costs or use it on another vehicle?

Personally I can't stand buying poor quality parts - not just for the poor performance and reliability - but I don't like supporting the manufacture of these inferior parts by purchasing them.

Remember - the quality remains long after the price is forgotten.

I think your code 42 is probably a symptom, not a cause. This is usually a result of a bad ignition module in the distributor.

GD

IROCZman15

iTrader: (25)

very very true indeed

was hoping for something about half that price just in case it doesn't resolve my wacky issues . I'm kinda pushing the budget limits as it is for car projects in 2019 with my moser 12 bolt rear and the beefy driveshaft and brake system alterations

i could always sell it later though. next engine will be built "turn key" and shipped to me I'm not skilled enough to assemble a 500 hp(plus nitrous) motor

therefore a middle grade distributor just to get me through 2019 or to better troubleshoot the overall ignition problem is what im hoping for.

nonetheless, you are dead on right about good parts i do agree. almost all of my parts are the expensive usa or big company names, moser, pro built automatics, UMI, koni, moog, Boze forged, NOS, hooker, hawks, BFG, so I agree that is the route to go for long term use and performance. maybe just not for troubleshooting this particular short-term problem ?

GeneralDisorder

iTrader: (1)

I think for your needs - a good used GM distributor from the member classified section might be the ticket. The factory units were quite good. Try the parts wanted section of the forum here, and ebay is a good source.

GD

IROCZman15

iTrader: (25)

GeneralDisorder

iTrader: (1)

Yep - those are right. And yes they have it listed wrong - 87-92 would all use the small cap distributor. 85/86 are large cap.

GD

IROCZman15

iTrader: (25)

Thank you guys or all the help and input during this process.

I decided to buy a new distributor. Removed my oem one that I had put the new $9 pickup coil in just a week before.. It is not "mangled" but just seems worn-out. I'm no expert so I don't know exactly what the tolerances between components should be , but it just seems sloppy... 172,000 miles on it since 1987. New distributor was from Jegs. came fully assembled. I could have gone for the more expensive ones from DUI, performance distributors, pertroix, msd, but I settled for a middle of the road version and knew that if I had a problem, I could get a new one in two days time direct from jegs.

Installed it last week after checking the ohms on pickup coil. Also, cut off the old grey connector at the remote coil and replaced it. also cut off the worn out connector from the ICM to the ECM and replaced it. both of those were on ebay, less than $10 a piece.

Car fires up, and runs pretty good. set timing at 6 deg advanced with ESC disconnected. As I was setting the timing to 6, a few times when I had it right there at 6, the engine would jump up higher rpm's and the timing would go to about 10. I then would back ti down, and a few moments later it would jump down to almost where I initially had it. what the HECK is that about!?! why would that happen?? so, now I have it where it seems happy, but its about 8deg with esc unplugged. This has happened with teh car for years. At idle, it likes to jump around from time to time. not all the time either. sometimes hot, sometimes cold. it doesn't like to hold a steady idle. i was HOPING the new distributor would maybe by-chance fix this issue, but it didn't. It makes it difficult to set base timing, that's for sure. anyone have thoughts on this? Its an old ongoing issue I just let it happen and adapted, but would love to have it be fixed. thoughts.?

the car revvs great and has power, but the exhaust sounds different. small burbles/pops and is "spitty", cant think of a better word, but sounds like it is spitting? took the car for a road test and the car runs good. I still have the fuel tank filled with fuel from November and Stabil so i'll burn through that soon. Will pull out a few spark plugs too and read them also.

HOWEVER, the car will still NOT run when wired to the MSD digital6 box. I had them on the phone twice and even did the box-test with them on the phone and they could hear it sparking as I conducted the test. they suggest sending the box in again, maybe I'll just have to do that. I do use it for nitrous spark-retard, so I would lie ti to be functional. however if it becomes too much of a problem, I can just run the car "as'is" with the stock wiring configuration.

Cant go for a long drive just yet as I need a full wheel alignment now after installing a brand new Moser 12 bolt and I want to make sure all my alignment settings are acceptable.

GeneralDisorder

iTrader: (1)

FWIW I just installed the small cap DUI distributor and matching coil and it was a beautiful product and runs amazing. I didn't want any Chinese foolishness or tail chasing.

GD

IROCZman15

iTrader: (25)

nice. I saw you had a thread about large/small cap distributor stuff on here.

I am ABSOLUTELY positive the jumping around of RPM and timing is NOT the new distributor. the car did this before, for years. I would be at idle, in traffic, or in my driveway, and the rpms would jump up a bit on its own and back down. I was hoping that the new distributor would have fixed this, but its some type of of other problem. absolutely , guaranteed, this has been happening with the car for years and years. , sure would LOVE to solve it, but don't know what it is ? I used to think it was a vacum issue, something under the TPi, but I have since verified that all vacum passages are connected. maybe a vaccum tube is collapsing on itself internally and I can't see it happening...? its certinaly not a new problem related to the ignition components that this thread discusses. no way.

GeneralDisorder

iTrader: (1)

Loose timing chain? With the ESC disconnected it should be rock solid at 6 degrees. Just set mine last night and it never moved from 6 degrees till I reconnected the ESC and cleared the ECM. My timing chain was pretty sloppy at 155k. If it's got 172k on it.... I would say that's definitely suspect. But you say your hitting it with N2O so that would lead me to suspect the engine's been gone through at some point.

GD

IROCZman15

iTrader: (25)

update:
got the cars wheel alignment done early this week and since then have put about 80 miles on it. it is always nice when spring comes around and I get to drive the car. no ignition issues on the current configuration which is: the new Jegs distributor and its icm and pickup coil, the gm oem ignition coil, and NO msd digital6 cd box... the msd box I decided to send back to msd for testing . i spoke to them Wednesday to see how their diagnosis was going and I was told that they found a melted diode inside the box which would cause it not to work. they asked if I had applied 12volts directly to the signal wire and i said that I did not, but informed them of my ignition issues and the melted cap/rotor, and questionable pickup coil (all discussed above) they repaired the box for $35 and will be shipping it back to me hopefully this week. the car currently does run pretty good as it is configured but I am unable to use nitrous without that box to control spark retard. so we will see how it goes when it gets back. MSD doesn't really seem super helpful on the phone because I asked them what could have caused the problem (so it doesn't happen again) and they don't offer much guidance at all . I'll call them again and hopefully get a different tech on the phone.

thats all. glad the car is up and running. the ignition issue had/has me still concerned. but its nice to drive with the new moser 12 bolt, dennys 3" driveshaft, and adjustable wilwood rear prop valve all working. ..

the only one issue I am having to troubleshoot is my engine temp gauge on the dashboard cluster. it was reading weird for a while. then it started pegging below zero. it would get stuck behind the metal decorative gauge trim bezzle. this happened often during winter car testing sessions, so I would finger swipe it back out from behind the bezzle. Just today i inspected the wiring, decided to put a new spade connector on the wire and also replaced the temp sending unit in the block. now the gauge pegs when cranking but then a finger swipe to loosen it will let it move around and then display readings.. but they are the WRONG readings. it is telling me my engine temp is at 220 and then goes up from there. I used a temp gun several times today and verified I do not have anywhere near 220 deg or above. I think my frequent finger fiddling with the gauge needle and its swivel piece may have screwed up the gauge and its baseline?. thoughts? also, I used about 3 wraps of teflon tape on the threads of the new Dorman coolant temp sender where it threads to the block. I didn't want fluid leaks, but now I am thinking...... maybe I should not have used the teflon tape.. would this interfere with the sender/sensors grounding to the block? should I pull it out and get rid of the teflon tape? should I get a new/replacement gm oem temp gauge for the dashboard. all wiring is good from what I can see under the dash and in the engine bay. I did a few searches here on TGo and learned a bit already, but figured I would ask you fellas instead of starting a new thread on an already discussed topic .

NoEmissions84TA

iTrader: (1)

You can answer your own question about the grounding of the gauge sender by using a piece of wire connected to a known good ground location and touching the other end to the BODY of the sending unit. If your gauge reading now falls into line, then you have your answer.