TKR Performance

iTrader: (1)

I fixed mine by replacing the distributor. I took my old one apart and all the pickups look like they just came off the Titanic. Rusty as all get out. So I got a brand new one from Advance ($90) with a lifetime warranty and just put my ignition module into it. If it ever breaks again I get a new one... no questions asked!!

oldred95

Did a few things tonight. First of all I pulled the plugs and regapped from .045 to a stock .035 just to see if it changes anything. Didn't drive it though, decided to go deeper. Put the MSD blaster stock replacement coil back on because I noticed some pretty massive white streaks going down the sides of the stock coil which is kind of why I replaced it to start with so the MSD is back on for now. Pulled the cap and the center button was stuck up inside the cap. Fiddled with it, oiled it, then it just fell out in my hands all deformed and the spring was pretty much melted. The contacts looked good and the cap can't have but 6-8 thousand miles on it. Even the contact on the rotor where the button rides was smoked. Not sure what that says about MSD. Guess thats what I get for buying it for the sake of having a body colored cap. So I picked up a Duralast Gold cap and rotor at Autozone because its got a 5 year warranty and supposed to have a stainless steel spring and what not. I was hoping for a stainless steel center button but it doesn't but the terminals are all brass. Anyway. Pulled the distributor and rechecked things. The end play was tighter then I remember it being, a .015 feeler gauge just took up all the slack. The magnets felt ok and after looking at it there are four points around the magnets that they draw to and make for kind of a bump when you turn the distributor by hand. The distributor would roll around and bump and hold itself there with just the magnets fine. It had a noticable feel to it as the magnets passed by that point so I figure thats not too bad for its age. It got dark out before I got to putting the cap back on so I will know more tomorrow. Things are bound to be better at this point though. A bad coil, a smoked cap and rotor, surprised it even ran really.


Does anyone make a cap that has a brass or stainless center button and is there a reason why they don't and make them out of carbon? I don't get it.

dimented24x7

iTrader: (2)

As far as the cap goes, I've had similar issues when the rotor doesn't sit far enough down. This ends up overloading the contacts as they are forced together rather than by sping tension alone. check to be sure the rotor your using seats down all the way.

oldred95

Good point. I will have to measure the installed height and see whats what.

oldred95

Well its a partial no go. I reflashed the EBL with an updated version of the bin that was currently in it. It would start and run for about half a second and die like someone shut the key off. Would not restart. Uploaded an old bin and it would start and run. Thought maybe the bin I was wanting to use was corrupt but it all displayed correctly in tunerpro so I copy and pasted all the changes I had made to a copy of the older bin that it would run on. Would not run, start and die. I started it off the good bin and then uploaded the one I was wanting to use and so long as I kept it above idle around 4% throttle and above it was fine. Anything under and bam like you shut the key off and would not restart. I've looked things over and can't figure it out. I made a couple small changes to the IAC throttle follower but I can't imagine it causing it to not start and run like this. Its pissed me off for the night anyway, maybe it will run tomorrow.

Ronny

iTrader: (1)

You are using EBL.bin (s) ???? Key on engine off you are seeing the blinky CE right?

oldred95

No I am using the maf tbi code with an ostich emulator.

Ronny

iTrader: (1)

Quote: I reflashed the EBL

Does not EBL require EBL.bin use?

How about the blinky ?

oldred95

Figured it out. Started it and let it run on the older bin I didn't want to use but started copying and pasting changes over from the bin I wanted to use and updating the emulator until I killed it. The culprit was the constant initial IAC flow after startup. I had been toying with it to try and clear up the start issue and changed it from 187 to 190 just for a nice round number. Evidently 187 is as high as it goes, anymore more and you make the PCM go brain dead.


Drove it and it runs better then it has in years but starting around 4500 it starts breaking up still. Its not terrible but its there. I guess I will just break down and get a DUI distributor sometime and probably one of their coils and just be done with it. I mean EVERYTHING else has been covered, the shaft magnets are kind of ragged and its old, so its about go to be it right?

JeepYJv8

I had a same problem, i havent reaad all the posts here, but here is my story!!
About 8 months ago. breaking up over 4k rpm. Any white on plugs? i have fuel pressure guage under my hood, i would rev it up in the driveway and it only dropped about 1-1.5 psi , so i figured it was ok. I then checked/changed everything else imaginable. then started back at square 1, and figured it was tuning issue. but then i decided to try and view the FP while i was driving, and log the file. i took it for a ride and quickly noticed the fuel pressure was about 6 -7 psi while under driving load. i changed the filter and it got better, but ultimatly changed the fuel pump and i was cured! i hope you get it figured out, good luck

dimented24x7

iTrader: (2)

The IAC flow is primarily controlled by the IAC flow vs. % cool temp. If the battery voltage is above 8V, the PCM will move the IAC to this position as soon as the engine starts cranking. Also, what is your mask ID set to? Additionally, which XDF are you using? I think I sent you a new one awhile ago, but go into the '427 $0D MAF tuning thread and grab the latest XDF for tuing, just to be sure that your up to speed. There is an early XDF that has a few errors in it.

Also, since youve been using an emulator, can you send me a copy of your bin? Sometimes those can corrupt the hell out of the bin since you dont have a checksum enabled. The PCM never gets a chance to verify the contents. It probably would be a good idea especially since you had problems when you changed the IAC park position. That shouldnt cause the PCM to lock up. Its possible that the bin your using could be corrupt, and could be the result of your current problems. I can take a look at it and make sure its still legit.

oldred95

Thought it was time to revisit this. I finally installed a new 02 sensor a while back, went back to closed loop and collapsed the lifters to within about .010 inch of being fully collapsed. I was thinking was getting a lifter collapse condition due to old high mileage lifters in an old high mileage engine but that didn't seem to be the case. It did clear things up slightly but it wasn't the entire problem either. Between that, fixing the ignition issues (coil and cap and rotor and plugs gapped at .060) the truck runs the best it has in years under 4 grand. It actually idles smooth now even in closed loop at 14.7:1 sometimes smooth enough you can't even feel it running. The distributor is the only thing left so I guess I will have to get a DUI unit sometime when I get some spare cash. I just don't know what else it could be.

dimented24x7

iTrader: (2)

With the lifters, you can check that quickly by revving the engine in neutral while listening to the engine. If the lifters are bleeding down, they will have a cyclitic clatter at evenly spaced RPM intervals as you raise the RPMs up. If theyre quiet, then the lifters are not collapsing or bleeding down. Most aftermarket lifters will do this to some extent due to the design. They usually have faster bleed down rates than the stock ones to give an anti-pump up feature.

As for the ignition, the stock HEI stuff isnt that great. I remember how much better my car ran when I switched to my current late model ignition.

oldred95

Are you using the 350 vortec style distributor? I'm just about ready to cut my losses with the stock one and change to something, either a stock DUI replacement or whatever a better option is.

dimented24x7

iTrader: (2)

Yeah, the crab style one from the vortec trucks. Its actually an aftermarket billet one from summit. These dont use a conventional module. Instead, the PCM controls the ign. coil directly thru an amplifier, so the amp can be located remotely from the distributer, which is a big improvement as the power transistor works much better when its kept cool.

oldred95

What all is envolved in converting to the vortec style distributor? Summit has a Summit brand aluminum housing replacement vortec distributor for 161 complete from gear to cap and rotor. It appears to be identical to the DUI brand unit which is 190 dollars. I believe either would do the job though. As for the distributor it will just drop right in no problems.

Next would be the plug wires. I've got almost new MSD super conductors that were cut to fit and fit very very well. They are about a year old but maybe only a few thousand miles on them and I would rather reuse then buy new, especially since the super conductors don't seem to come cut to fit with vortec style wire ends. That brings me to my next idea. There is no reason why I can't just install different ends at the distributor cap, I know there is enough extra length and with the crab cap it actually will help with that as well. So I did more searching on summit and it appears they are calling the vortec style distributor end plug wire connection a "coil pack" style end.

http://www.summitracing.com/parts/MSD-3304/

I believe I can still make the 45 degree angle boots still work so long as that is the right style of terminal for the vortec cap.


Next is the coil. Do I need a vortec style coil as well or do I reuse a stock style TBI coil? Either way its getting a DUI brand coil, its just a matter of what style I need, vortec or TBI.

Last would be the ignition module. What module are you using and how is it wired up? IIRC the vortecs use the same 4 wire connector on the module as the TBI igniton module. Is it just a matter of plugging the stock harness connector into the ignition module? At that point how does the module connect to the coil to power and control it?

dimented24x7

iTrader: (2)

I alluded to this in my above post, but teh vortec distributer requires a late model PCM to operate it as there is no module to control the coil firings. The PCM itself has to operate the coil directly to fire the ignition. There is no external logic in the system. The distributer just has a hall effect in it to let the PCM sync up with the #1 cylinder firing. The "module" is basically just a power transistor and associated circuitry to amplify the waveform that comes from the PCM.

The biggest problem with the stock ignition is that the module is in the distributer. You can get all the benefits (well, most, anyway) of the late model vortec type by simply relocating the module to outside the distributer to get it away from the heat. Its the heat from the engine that kills the module and impedes its efficiency. The way to do this is to make up a harness that goes to the module that has the signal wires, power, and twisted pair for the pickup coil. You can then relocate it to the firewall up near the cowl with a good heatsink. I think the heatsink for the vortec module will fit, and can be used. The only other thing that will be needed is to ground the heatsink as the module grounds thru the base that its mounted to. This will GREATLY reduce the operating temperature of the module and make it much more reliable.

oldred95

I didn't realize you were using a OBD2 pcm. So at this point my only real option is DUI stock replacement distributor and relocating the module out from under the cap.

Chris is telling me I should look into the computer controlled big coil in cap HEI unit like the 90-92 TPI vettes used. Any info on this?

dimented24x7

iTrader: (2)

I dont know about the big coil HEI one. Ive never had any experience with it.

oldred95

He said he used one when he first switched to TBI on his van. If the TPI Corvettes used it I don't see any reason why it wouldn't work. I know the 4 way connector to the module is different, the large cap HEI just uses a standard 4 way weather pack connector but thats easy enough to change. It also has to get power and a tach signal but I've yet to find a picture of the connector or where it plugs in at on the distributor. I'm just wondering what other hidden things I'm going to run into. It sounds all too easy to drop an entirely different design distributor in, change a connector or two and have it fire right up.

Here is the diagram on the large cap HEI ignition system.

dimented24x7

iTrader: (2)

It should work as the signals to the module are essentially the same. The tach signal will come off of the coil. From the pics of them, it looks like there is a seperate two pin connector that has the +12V, and tach leads as well as the 4 pin connector that you referenced.

va454ss

iTrader: (1)

Wonder why he would recommend the large cap over the small cap. I was running the large cap on my truck, but switched back to the small cap unit.

It is that easy. You will need to change the latency values.

https://www.thirdgen.org/forums/diy-...hlight=latency

https://www.thirdgen.org/forums/diy-...hlight=latency

95 4x4

iTrader: (1)

oldred95 this is what i'am running in my truck using the D.U.I. Computer Distributor Part No. 12620 , Screamin' Demon Coil part no. 31723 . Their will be no issues with the module over heating as it a different animal inside . I did gap my plugs .060 and i also went one plug colder . One other thing you will have to run good wires which i think you already have . Been runing the D.U.I. now for a year with out any issues , this is one SWEET set-up .

EagleMark

Will a large cap fit in a camaro?

oldred95

I think he recommended it to me because its capable of producing an incredibly hot spark, its something different that will still work, and it should cure my problem. Either way a new distributor should cure my problem but I'm starting to like the coil in cap idea because I've not no real good place to put a coil on the intake and where its at now is just kind of cluttered.

Any reason why you switched back to the small cap? I've got all sorts of space to work with, the size of the cap isn't going to be a concern at all. I will have to look into the latency stuff.

dimented24x7

iTrader: (2)

The dwell parameters for the ignition aren't defined in the XDF. I know where they are in the code, but its not one of those things you usually edit due to the tools needed to accurately determine the proper dwell for the coil. Same goes for the spark latency for the distributer. I can add them in the XDF for you when you get the proper tables for the big cap.

oldred95

I did some digging and found the Corvette large cap HEI bin and XDF last night on moates.net but wasn't able to find the complete hack. I did find the spark latency table in the MAF OD hack and added it to my XDF and it was correct, matched the values listed in the Hack for the given address. I know we've had issues in the past where the address's listed in the Hack were not accurate due to the amount of changes within the code itself. Anyway the tables did match up but what I find odd is in the threads va454ss referenced my values for small cap HEI looks nothing like the values posted in the thread for small cap HEI. I don't see why there should be any difference if the two parts being used are the same.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;-Spark latency correction vs. RPMs
;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
;
L4540 FCB 192 ;4800 rpm, UL for lookup
;
; usecs = val x 15.26 ;RPM
;
L4541 FCB 0 ; 0
FCB 0 ; 400
FCB 0 ; 800
FCB 3 ;1200
FCB 7 ;1600
FCB 9 ;2000
FCB 9 ;2400
FCB 12 ;2800
FCB 11 ;3200
FCB 9 ;3600
FCB 10 ;4000
FCB 10 ;4400
FCB 9 ;4800

va454ss

iTrader: (1)

I was advised to use the large cap due to the terminal spacing. Originally, I was going supercharged and supposedly the wider terminal spacing would help prevent crossfire. I was using a DUI unit.

Began having same issues that you have, so I switched to the small cap, but it hasn't cured my problem. I concluded I had weak valve springs (beehive). When I was in the process of changing valvesprings, I found 3 valves weren't sealing. Engine builder concluded that the weak springs had caused valve bounce and some of the valve heads had gotten "tweaked" and weren't seating properly.

Pulled the heads had everything checked out and installed new springs. In my case they were set up for me to run solid rollers on my hydraulic roller cam. Put everything back together and still have same issue.

dimented24x7

iTrader: (2)

Sounds like my experiences with the HEI system. It would be interesting to put a scope on it and see if it really is a problem with the ignition. I can say one thing that I had nothing but problems with the HEI system on my car. It would be fine until I started running the engine hard. After a couple of hard runs, the engine would slowly loose power over time as the module slowly degraded until one day it just wouldnt start, which would usually be some place where its inconvenient to have to change a module. I mustve gone thru at least 6 or 8 modules. Maybe more.

va454ss

iTrader: (1)

Well, I've run multiple small cap distributors and multiple modules in those distributors with no change. Matter of fact, I tried 2 DUI big cap distributors also. Have also used the GM dual connector coil, and 2 different oil filled canister coils. Different spark plugs and wires. I would say after all the parts swapping I've done, its hard to believe its the ignition.

I've swapped EBL's and Autoproms also.

Tried shielding the 4 wires from the distributor too.

Considering swapping to a carb temporarily to eliminate a mechanical issue with the engine.

oldred95

You guys don't exactly instill the confidence do you.

va454ss if it were the valves not sealing completely you should have noticed that at light throttle high vacuum stuff, especially at idle. Under high loads there is more pressure in the cylinders and slight leakage doesn't have near the effect on it at that point as it does near idle.

I've got one more thing to try. Injector advance. I've had it set at 60 degrees for who knows how long but I'm going to back it off to 30 and see if anything changes tonight.

oldred95

I got to thinking about this today at work and in my case it about has to be weak ignition. Several years back I had a Honda ATC 125 and for the longest time I fought this WOT misfire on it too. I had the carb off probably 15 times checking and cleaning and rechecking. Tried a different carb, nothing helped. Finally one day it stopped running all together and had no spark. I took the CDI box off and slammed it down on the concrete floor about 10 times as hard as I could, put it back on and it ran better then new. It idled better, throttle response was better, and it would flat out scream for a little 125. I would hate to guess how many rpms that little thing would turn but the misfiring was gone.

Thinking about my truck and how its gradually deteriorating I can't help but think its a weak ignition system. Why I'm not sure but it seems that way. I tried 30 degrees of injector advance to no avail. I've yet to be able to make heads of tails of my accel enrichment. At light throttle high vacuum it keeps wanting to run lean and there is no reason for it to be, even closed loop can hardly compensate for it and when I step into it it goes insanely lean almost to the point of stalling. The lean bog on a WOT stab seems to be getting worse no matter how much I try to correct for it. If its not ignition I don't know what else it can be.

EagleMark

Many years ago with a Big Block Chevy Nova race car, 1/4 mile. It would break up at high RPM. A guy said change the plugs. We said they only have about 5 runs on them, he smiled and said changed plugs. Several runs later with no other ideas, we changed plugs. Ran perfect! After that the car only made 3-4 quarter mile runs before breaking up at high RPM. Change plugs...

Also use stock factory plugs gapped at factory setting. I don't want to tell you how many problems I have seen and read about that boiled down to aftermarket plugs or just a little differant factory plugs.

ASE doc

dimented24x7 mentioned checking ignition patterns on a scope. Your problem sounds exactly like ignition drop out. Right down to going lean on WOT and light throttle tip in. You can't test drive while connected to a scope, unless you have a chassis dyn. But you can use an in line spark tester to look for spark drop out.

The O2 sensor does not recognize HC. It only measures O2 content. Since ignition misfire leaves high O2 content in the exhaust stream, the O2 sensor sees it as lean exhaust. This makes the failure look like a fueling issue. In closed loop the ST fuel trim will even try to compensate, resulting in even more HC.

When this HC rich air, which just what it is, hits the catatyst, it combusts, partially anyway, often resluting in black smoke at the tailpipe. This can make the lean O2 sensor data even more confusing.

RBob

iTrader: (1)

If an O2 sensor (NB I presume!?) can't recognize hydrocarbons (HC), then why/how does it output a voltage above 450 mV?

RBob.

xch3no2

Once at operating temp, volts above 450mv represent a lack of o2, not the presence of HC.

dimented24x7

iTrader: (2)

I think the operation of a typical O2 sensor is based reactions involving oxygen, CO/CO2, and water (wideband). My recollection is the oxygen is stripped away, and transported across the cell to power the reaction. Any time there is incomplete combustion, the sensor isnt accurate. Lean misses, cam overlap, overly rich or lean combustion, poor ignition, etc. will all cause the apparent AFR to be incorrect as there is surplus oxygen and unburned fuel.

This was a problem with my old taurus when it developed a vacuum leak at one of the cylinders. That cylinder shut down due to being overly lean, while the rest in the bank went pig rich as teh computer increased the fueling to try to hit "stoich". The end result is the other 2 spark plugs on that side becoming fouled, terrible fuel economy, and flooding on startup.

Edit: Come to think of it, the narrow band cell is basically responding to the demand for oxygen across it. Rich mixtures have lots of remaining combustibles, but no oxygen. This creates a demand, which pulls oxygen across the cell. I think in the case of a misfire, the oxygen is already there with the fuel, so none is pulled across the cell as the oxygen is already there for the reaction to take place on the exhaust side of the sensor.. In a fully burned rich mixture, the oxygen has been depleated, so there is a demand pulling oxygen ions across the cell, creating a potential.

RBob

iTrader: (1)

A NB O2 sensor (staying with the same type of sensor), has a platinum coating on the cell. Platinum being a catalyst will burn any HC present in the exhaust stream. This causes oxygen to migrate through the cell causing the output voltage to increase.

The O2 sensor is responding directly to the level of HC's in the exhaust stream.

RBob.

Ronny

iTrader: (1)

Re: WOT misfire, breaks up after 4000 rpms

This is exactly what my vehicle did after adding N20 setup. I puposefully errored on rich safe for jetting when I started tuning for N20. Car responded well on WOT-PE for a couple secs then it broke up on a misfire. Innovate WB went to 10.5/1 initially then went to max lean 22/1. 22/1 it was reading the misfire and incomplete combustion IMO.

Is it possible you are very very rich?

dimented24x7

iTrader: (2)

I agreed with this in my above post. Its essentially calalyzing combustibles at its surface to generate the demand across the membrane for O2. What I was saying is taht additionally if there is already oxygen mixed in with the HCs, exhaust, etc, due to a misfire, there will be little or no demand across teh membrane for O2. Ive seen this when there is a fault that causes one cylinder to drop out. All the rest around it will be forced pig rich due to the false lean condition.

xch3no2

So to correct myself, I would say that the over-volts represent a greater demand for o2 in the exhaust, due to unburnt HC. Thanks RBob!

As dimented pointed out, they just can't tell us how/why the HC gets there.

oldred95

Call me a tight a$$ but does anyone know of any Summit discount codes yet for 2011? I'm ready to order up the distributor but I know as soon as I do there will pop up a discount code to save me some money. I'm checking with S10wildside on connectors for the large cap HEI. The ignition module appears to be a standard flat 4 way male weather pack connector and the tach and ignition feed appear to be individual female connectors of some sort. Didn't see them on efi connection but I've already contacted them and hopefully they have what I need.

ASE doc

This seems to fit with my experience. Ive tested narrow band HO2S by monitoring O2 data, STFT, and HC/CO on my 4 gas analyser. Killing cylinders by removing spark caused HCs to go high, and in low O2(lean) data readings. The STFT actually increased, even while the exhaust was loaded with unburned fuel. This verified what Ive found in cases of ignition drop out.

xch3no2

It might be worth cutting/drilling a spare cap to check rotor phase on this deal.

dimented24x7

iTrader: (2)

For the connectors, you might also try autopartsgiant.com. Ive gotten a lot of those weatherpack connectors from them. They decided to "update" their search engine, tho, so its hard to get their invintory to show up, but they used to stock LOTS of weatherpack conectors. Ive gotten a number of them over the years.

Another place to try would be dormans web site. They have crimp connectors for replacement. The other option would be to simply cut the existing connectors off the pigtails, and reterminate with some standard weatherpack connectors.

84elco231

Just thought I'd throw this out there, I know you've put a lot of time into chasing this gremlin down and have probably gone through every imaginable ignition/fuel system aspect imaginable, but sometimes misfires at high speed can be caused by plugs, especially ones that may have a light coating of piston aluminum on them from pre-ignition? This is one reason I run cheap copper plugs. Just thought I'd mention this as a long shot...

va454ss

iTrader: (1)

http://www.eficonnection.com/eficonn...spx?ItemId=973

http://www.eficonnection.com/eficonn...spx?ItemId=972

http://www.eficonnection.com/eficonn...spx?ItemId=550

Also an adapter to go from big cap to small cap (you're going the other way):

http://www.eficonnection.com/eficonn...spx?ItemId=792

http://www.pegasusautoracing.com/gro...ID=WEATHERPACK

ownor

iTrader: (5)

Care to elaborate some on this technique?

xch3no2

You create a window in the distributor cap, inline w/#1 plug terminal, so that you can observe the rotors alignment with a timing light.

It helps to paint a thin white stripe on the rotor contact centerline.

You might be surprised about how poorly aligned things get (and the problems created) once the distributor has been moved.

EagleMark

It also helps diagnose a harmonic balencer that has slipped on it's rubber vibration ring in the middle. Not sure if this is applicable to this car...