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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Brand new BWD Select ICM > Swapped Ignition Coil > Original ECM > Same dang outcome. It will "force run" with the pedal slightly pressed but makes the strangest high pitched noise I've heard. So if it will "force run" the fuel pump is running and so are the injectors? So the ECM is completing the ground on the injector circuit? It has to have continued spark for the force run to be possible?
Checked oil level and it's mid way on the dipstick. Will TunerPro tell Oil psi from the ops? It's also very oily in the ops area, very like somehow oil is getting past that very tightly installed ops, at least I couldn't turn it by hand while under there cleaning plugs. Will a datalog of a SHORT forced run tell anyone if the issue electronic data sensor related OR engine mechanical?
I'm ready to tap out I'm open to all suggested troubleshooting!
Hi Ed
I got to the party late so apologies if you've been over this. Maybe similar situation, maybe not. Car ran great then had it apart for unrelated work. Fired it up, ran poorly then no start condition. Adjusted timing, checked distributor in right (several times) checked plug wires for order, no. Changed plugs, no. Changed cap, rotor and swapped wires, no. Checked and changed coil even though testing said it was OK, checked pink wire and spark thru to cap, OK. Spark at the plug was OK but not super strong. Replaced ICM twice, no Ohmed injectors (Bosch 111’s), app 14.7, pulled them (9 volt battery), sprayed fine. Checked every connection, checked ground strap, fully charged battery, etc. Also tested the pickup with a voltmeter and supposedly it was OK. So I bought a new Spectra distributor to eliminate the cap rotor icm and pick coil all at once and ... the car now runs. All of the existing parts were only a couple of years old and car barely gets any mileage. My guess, bad pickup coil.
Something appears to be going on with your TPS. It starts out at .61V at 0% TPS. But then it's all over the place while your pushing the throttle down. When you get back to 0% TPS, the voltage is at .94V.
I looked at the data with three different Tunerpro ADX files and it gives the same result.
Something appears to be going on with your TPS. It starts out at .61V at 0% TPS. But then it's all over the place while your pushing the throttle down. When you get back to 0% TPS, the voltage is at .94V.
I looked at the data with three different Tunerpro ADX files and it gives the same result.
0% TPS started right when the Engine Run Time started counting, my foot on the pedal, engine running at least 15 seconds. Gmsm Code 22 TPS circuit troubleshooting states "With throttle closed, the tps voltage reading should be less than .96V". so if i'm understanding what you've pointed out TunerPro see's the engine physically running on what appears to be reporting as a closed throttle?
I'm saying that your TPS% should be proportional to your TPS volts and according to the data it isn't. The % curve and the volt curve should look identical, just offset from one another. But you can see how the % curve goes haywire when you open the throttle. The curves are the TPS % and TPS voltage vs elapsed time.
When your % curve goes back to 0, the volt curve doesn't return to the original value.
Recommend you look through your data to verify. I've had it happen before where I look at someone else's data, it appears garbled when it isn't. But like I said, I looked at your data with 3 different ADX files, so to me it appears real.
Hi Ed
I got to the party late so apologies if you've been over this. Maybe similar situation, maybe not. Car ran great then had it apart for unrelated work. Fired it up, ran poorly then no start condition. Adjusted timing, checked distributor in right (several times) checked plug wires for order, no. Changed plugs, no. Changed cap, rotor and swapped wires, no. Checked and changed coil even though testing said it was OK, checked pink wire and spark thru to cap, OK. Spark at the plug was OK but not super strong. Replaced ICM twice, no Ohmed injectors (Bosch 111’s), app 14.7, pulled them (9 volt battery), sprayed fine. Checked every connection, checked ground strap, fully charged battery, etc. Also tested the pickup with a voltmeter and supposedly it was OK. So I bought a new Spectra distributor to eliminate the cap rotor icm and pick coil all at once and ... the car now runs. All of the existing parts were only a couple of years old and car barely gets any mileage. My guess, bad pickup coil.
Brian
I will keep this in mind, and will likely go this route once all other free options are exhausted. I looked at the Davis Unified Ignitions distributor upon reading your post but a fellow member, just today, also posted a 2 or 3 star review of the "Dyna-Module" ICM included in the D.U.I distributor so now i'm on the fence. Can't pay $200 on a dizzy where the included $65 ICM is by some defined as a certified "P.O.S" lol. How long has the Spectra dizzy been installed? Did it come with an ICM? Lifetime warranty?
Originally Posted by ULTM8Z
I'm saying that your TPS% should be proportional to your TPS volts and according to the data it isn't. The % curve and the volt curve should look identical, just offset from one another. But you can see how the % curve goes haywire when you open the throttle. The curves are the TPS % and TPS voltage vs elapsed time.
When your % curve goes back to 0, the volt curve doesn't return to the original value.
Recommend you look through your data to verify. I've had it happen before where I look at someone else's data, it appears garbled when it isn't. But like I said, I looked at your data with 3 different ADX files, so to me it appears real.
Did a Key ON Engine Off Log of TPS voltages. What we might be seeing the GMSM defines as a closed throttle. Anything below .96V the ECM believes the throttle is closed. I take this to mean "my foot moved" while trying to hold the pedal down just enough to stay running. Everything in this log looks like above .96V the percentage & voltage are in line. Your thoughts? I also appreciate the excel spreadsheets and chart. How can I build those charts in TunerPro?
I am late to this party. Do you have spark yet? Post #5 tells me that it's your rotor arcing out to the mounting post of the distributor. Replace your rotor.
Ok, the TPS is more well behaved in this log. Not sure what happened in the last log.
To graph stuff in Excel, go to Aquisition in TP, then Export Log File. Once you get all the data into Excel, you can do what ever you want with it.
But, I'm not sure where to go from here on your no-start. Something is preventing your injectors from firing. Seems like the only thing left is the pickup coil?
Ed
My no start happened last month. After testing and replacing all my premium parts with more premium parts, I threw caution to the wind and bought the Spectra. That was the thing about the Spectra, $50 from Rock Auto for a complete distributor including cap, rotor and ICM and I figured Rock Auto would be good for replacement at the least. I was so frustrated that 50 bucks to get all new stuff in one package was worth it. Granted it's no thing of advanced engineering but at least I can now go back and start adding back in my good parts. Still can't say if this is your problem but if it helps...
I am late to this party. Do you have spark yet? Post #5 tells me that it's your rotor arcing out to the mounting post of the distributor. Replace your rotor.
Thanks, I will try this, I think we confirmed spark in Post # 8.
Ed
My no start happened last month. After testing and replacing all my premium parts with more premium parts, I threw caution to the wind and bought the Spectra. That was the thing about the Spectra, $50 from Rock Auto for a complete distributor including cap, rotor and ICM and I figured Rock Auto would be good for replacement at the least. I was so frustrated that 50 bucks to get all new stuff in one package was worth it. Granted it's no thing of advanced engineering but at least I can now go back and start adding back in my good parts. Still can't say if this is your problem but if it helps...
Brian
I've read no less than 10 threads where users reached the point of a replacement distributor. In each one of the threads it's also stated they tested their PU coils and supposedly they were within spec but still experiencing the same no start, with all the same troubleshooting completed, and the same wiring issues ruled out. That is until they replaced the distributor. I spent $40 on a ICM alone so heck why not another couple bucks on a rotor for testing and if that fails I'll just replace the distributor.
From post 5 Connected spark checker between coil and cap = Spark
Connected spark checker between cap and sp#1 (checker @ each end) = No Spark
From post 8 So the coil is producing spark? The test light in the spark checker flashes when connected between the coil & cap. How much kv? Unknown - How do I test this? Have you pulled the cap to inspect the cap and rotor conditions? Yes, both look nearly new to the naked eye.
You have spark at the output of the coil. You have spark at the coil wire. Unless the carbon button inside the cap is burned away, you have spark at the rotor.
You do not have spark after that. Where did it go??? If you look at your rotor very carefully with a 10X or stronger eye loupe, you will find a very tiny carbon track that is causing the spark to arc out to the center mounting post for the rotor.
I had this happen to me and pulled more than a few hairs out over a few days until I found it. Now I carry a spare rotor.
Whether I am right or wrong, you should put a new rotor in there just to rule this out. It's cheap and easy.
I can't say whether all of the other troubleshooting you have done has added more problems, or not. Good luck.
No thank sure I follow why the injectors loose 12v when plugged in.
just a FYI you can test coil output with this tester or there are testers that look like a spark plug without a center electrode that make the coil max out at 40kv.
No thank sure I follow why the injectors loose 12v when plugged in.
His first test used the engine as a ground reference, which is why he got 12V. I wanted this test to ensure nothing upstream of the injectors on the 12V source was bad.
The second test was to measure using the negative side of the injector plug as the ground reference. Since the ECM grounds the injectors to activate them, the ground is an open circuit until the ECM closes it, hence the 0V. This test confrimed no hard shorts in the ECM.
His weak/intermittent noid light response suggests the ECM is not getting what it needs to know when to fire the injectors.
His first test used the engine as a ground reference, which is why he got 12V. I wanted this test to ensure nothing upstream of the injectors on the 12V source was bad.
The second test was to measure using the negative side of the injector plug as the ground reference. Since the ECM grounds the injectors to activate them, the ground is an open circuit until the ECM closes it, hence the 0V. This test confrimed no hard shorts in the ECM.
His weak/intermittent noid light response suggests the ECM is not getting what it needs to know when to fire the injectors.
Anything less than 1Ohm was expected, right? It's suggested in this article post # 4 that 0Ohm's is a perfect reading with no resistance found.
Any other electrical based troubleshooting before I take a leap of faith and buy a new distributor? Wonder if the person below drove a ThirdGen
https://www.jegs.com/i/JEGS/555/40006/10002/-1
"I replaced my factory distributor with the JEGS 4006 billet distributor and solved my problem of burning up ECM modules, wish I had done it sooner at $60 bucks a piece."
Been shopping for distributors, can't find anything I'm comfortable with. $40 for a jy unit, $40 ebay unit, $50 RockAuto unit (LifeTime Warranty), $60 ebay unit (LifeTime Warranty). Most parts stores are $120+, and JEGS at about $96. They all honestly look the same like they all came from the came OEM.
Went w/ the RockAuto Spectra GM04 unit. $50 w/ lifetime warranty sits better on the wallet than something double or even triple it's cost. I was wondering if anyone takes the new icm out, applies a liberal amount of thermal paste before the install? Has it extended the life of a "bulk" icm? Read a review on JEGS where a vehicle ran 30sec and died because they skimped on the thermal paste from JEGS OEM...
Interested to see what happens. I hate diagnosing stuff, replacing it and still no luck. A real confidence builder... And thanks to ULTM8Z for the paste tip. I just installed the distributor as is. I'm sure the creampuff ICM that came with it will last longer with Arctic Silver.
If this wasn't a family oriented site, this post would be slammed with profane language. Words can't describe my frustration right now. Other than the trouble with the hold down bolt, I've replaced the distributor and it still cranks but won't run. I'm almost in man tears over here with no clue what to do...
Oil pressure switch => you jumped the terminals on the harness side - Correct
ECM and chip => You have others you've tried with no effect - Correct
Brand new distributor - Fresh out of the box
You've verified you have 12V to the coil during cranking - Spark checker on strong while cranking & in forced run.
You've measured the wire resistance from the ignition module connectors back to the ECM connectors - The purple Ref Signal wire w/ 0ohm's resistance found.
You've verified 12V to the injectors with key on engine off - No, Original result was 0V, this led to test 1 & 2. Double checked just now & current state is still 0V with koeo. Also did a force run and noid light was on. Would this conclude the ecm injector driver is operational and both new & old distributor were generating reference pulses?
You've verified the ground side of the injectors are not shorted internally in the ECM - Completed in 2nd Test. Results were posted in Excel Spreadsheet
You've verified you're getting good spark out of the coil (which would validate 12V to the coil during cranking as well ground side of the coil) - Spark checker on when connected to sp1 @ the cap.
You've verified you're getting full fuel pressure during cranking - Verified 44psi @ the rail with koeo, haven't tried while cranking.
You've verified the TPS voltage - Seemed correct in TunerPro RT in the forced run logs vs the GMSM.
You've verified your ignition timing (also distributor isn't set 180 deg out) - Original attempt at distributor replacement wasn't on point. In-fact I was worse off and it wouldn't even force run. Went back, re-verified I was on the compression stroke, cranked by hand until I felt air forcing past my finger and rotor was approaching sp1 ref mark, stopped when line on harmonic balancer was at 0* TDC on the timing tab and quit. Today I re-pulled the distributor out, reoriented rotor, dropped in making SURE cam gear meshed, cranked by hand a smidge watching the rotor move a smidge as the op driveshaft and distributor lined up and it settled into place. Cranked all the way back around and when the line on the balancer was at 0* TDC the rotor was now pointing at sp1. To actually "check timing" I'd need a helper to force run while I check it so might have to use a 2X4
Put every thing back, No dice. While I'm back to sq1 today, yesterday I was up $hits creek
The pink and white wire coil jumper pigtail is a common problem. Check it for continuity.
Checked the blk plug w/ pink & white wires between coil & icm... 0hm's on both wires. Couldn't check the grey connector on the coil, don't know where the other ends are.
It will "force run" with the pedal slightly pressed but makes the strangest high pitched noise I've heard. So if it will "force run" the fuel pump is running and so are the injectors? I'm open to all suggested troubleshooting!
Ed , I've read your whole thread here twice for good measure and the one thing that stands out to me is this ;
You talk of this "forced run" where apparently it will run but it makes a high pitched noise . From where ? The exhaust perhaps ? I'm left wondering if you've been chasing your tail with all this electrical parts replacement and what if your catalytic converter or muffler have failed in such a way as to be putting enough restriction in the exhaust to make it not run unless you "force" it with the gas pedal ? An exhaust restriction could fit both the forced run and high pitched noise symptoms .
Ed , I've read your whole thread here twice for good measure and the one thing that stands out to me is this ;
You talk of this "forced run" where apparently it will run but it makes a high pitched noise . From where ? The exhaust perhaps ? I'm left wondering if you've been chasing your tail with all this electrical parts replacement and what if your catalytic converter or muffler have failed in such a way as to be putting enough restriction in the exhaust to make it not run unless you "force" it with the gas pedal ? An exhaust restriction could fit both the forced run and high pitched noise symptoms .
I honestly don't know where the noise is coming from. 1st assumption was oil pump, because it sounded like it was coming from the engine bay area. The car has always had a tapping sound that came from below, and I always thought it to be the starter cover like on my 92 since the car was absolutely running. This here is out of the blue. I was daily driving it, parked it, came back 1wk later to this no-start. I have no info on exhaust restrictions or converter failures, more importantly where to even begin checking. What do you suggest?
Edit: In my visual inspection today after putting everything back together my sp1 wire may have been laying on my exhaust before this occurred, it's scorched to the point of being brittle and when flexed you can see cracks in the insulation. Another wire on that side showed signs of burn also. Do they make longer wires, is there specific routing or will any generic "performance" set work?
Last edited by 92RS-HeritageEd; Oct 2, 2020 at 08:30 PM.
I honestly don't know where the noise is coming from. 1st assumption was oil pump, because it sounded like it was coming from the engine bay area. The car has always had a tapping sound that came from below, and I always thought it to be the starter cover like on my 92 since the car was absolutely running. This here is out of the blue. I was daily driving it, parked it, came back 1wk later to this no-start. I have no info on exhaust restrictions or converter failures, more importantly where to even begin checking. What do you suggest?
Edit: In my visual inspection today after putting everything back together my sp1 wire may have been laying on my exhaust before this occurred, it's scorched to the point of being brittle and when flexed you can see cracks in the insulation. Another wire on that side showed signs of burn also. Do they make longer wires, is there specific routing or will any generic "performance" set work?
I always make my own wires so i can custom fit them. Have had my MSDs for the last 12 years or so and still going strong.
I think the car would still run fine with those wires, I found a couple in the same condition that didn't cause a problem. But..for an inexpensive replacement I used these. https://www.summitracing.com/int/parts/sum-g826r. Comes with a cutter/crimper so you can make your own to length. I don't have any reason other than thinking out loud but what about a Park/Neutral switch being out of whack or the starter circuit being faulty? Could the starter dragging make that noise?
I honestly don't know where the noise is coming from. 1st assumption was oil pump, because it sounded like it was coming from the engine bay area. The car has always had a tapping sound that came from below, and I always thought it to be the starter cover like on my 92 since the car was absolutely running. This here is out of the blue. I was daily driving it, parked it, came back 1wk later to this no-start. I have no info on exhaust restrictions or converter failures, more importantly where to even begin checking. What do you suggest?
Edit: In my visual inspection today after putting everything back together my sp1 wire may have been laying on my exhaust before this occurred, it's scorched to the point of being brittle and when flexed you can see cracks in the insulation. Another wire on that side showed signs of burn also. Do they make longer wires, is there specific routing or will any generic "performance" set work?
It's not likely that the spark plug wires would cause a high pitched noise , they would cause misfiring issues , AKA the classic "skipping" engine . I really think the high pitched noise is the symptom that's trying to steer you to the problem , and among the bunches of other things that could cause the high pitched noise it could be either a restricted exhaust , or a vacuum leak . Find the source of that sound and hopefully the problem will reveal itself .
I think the car would still run fine with those wires, I found a couple in the same condition that didn't cause a problem. But..for an inexpensive replacement I used these. https://www.summitracing.com/int/parts/sum-g826r. Comes with a cutter/crimper so you can make your own to length. I don't have any reason other than thinking out loud but what about a Park/Neutral switch being out of whack or the starter circuit being faulty? Could the starter dragging make that noise?
You thinking aloud is appreciated. I can look up the P/N switch in my service manual. The starter dragging sounds possible too. It does have that part that shoots out to spin the engine, I assume you mean what if that part isn't retracting and thus stopping the engine? So when I "force run" it I hear the sound it makes because it's not normally consistently engaged?
I would buzz out the harness with those links i posted.
Also check pressure while cranking.
You may also want to try some enginenstarter fluid. If it even wants to start like that, then you know you most likely have a fuel issue.
I'm going to make a spreadsheet using those links, so documentation of results is easier. Should my wire harness be in contact with say the transmission dipstick tube? There's a section that almost seems shoehorned down to wherever it goes. I can post a pic tomorrow
I'll also check pressure while cranking. I didn't consider Fuel Pump or the in-tank rubber feed line because it "force runs". When I had a failing in-tank rubber feed line on a 92 tbi car the car was fully operational except under hard throttle where demands where higher this is the complete opposite, this car will only "force run"
You thinking aloud is appreciated. I can look up the P/N switch in my service manual. The starter dragging sounds possible too. It does have that part that shoots out to spin the engine, I assume you mean what if that part isn't retracting and thus stopping the engine? So when I "force run" it I hear the sound it makes because it's not normally consistently engaged?
Kind of what I was thinking. The starter gear not fully retracting causing that noise. And, something intermittent electrical there in the circuit. How to test, not sure.
Heading out to collect data, below is the portion of the harness I mentioned. Idk how I'm supposed to check it because it has NO wiggle room. I tried dislodging it, but it's tighter than a smedium shirt. How did the trans dipstick end up in the middle, does it appear the outward portion of the harness is laying against something metal? Which I assume is a "ground" *if* whatever it is happens to be bolted to the engine block?
Jacked the car up, removed starter cover, bendix is not stuck outward. From this position I could see the wire harness is wedged between the trans dipstick & the AIR tube that leads to the cat. Can this tube be *slightly* bent out of the way? Safely? For clearance sake... it's not this close on my tbi car. Anything I can check while under here related to converter failures or exhaust restrictions?
Also, what happens when an oil pump fails? Could the sound be the oil pump crying because I've "forced run"? It's rather wet under here. I've never really noticed more than a few random drops in the driveway earlier in the year.
Well, after tinkering, changing back to my Jegs coil, etc got really smooth cranking and *whatever* the high pitched noise was it was not there. This "forced run" sounded alllllllllllllllllll good. Even rev'ed it several times, I was excited. let my foot off the gas, dead flat. Then I collected the below data w/ the ECM Disconnected...
EDIT: Also checked fuel pressure, 44ish psi in prime, drops to the high 30's while "force running"
Last edited by 92RS-HeritageEd; Oct 4, 2020 at 02:45 PM.
So car now starts and runs as longs as you keep your foot on the gas, or rev it or hold it at xxxx rpm, but as soon as let off the gas it dies? Did I get that right? Still can't think of the solution but maybe a bolt of lightning will hit me...
So car now starts and runs as longs as you keep your foot on the gas, or rev it or hold it at xxxx rpm, but as soon as let off the gas it dies? Did I get that right? Still can't think of the solution but maybe a bolt of lightning will hit me...
Car has always "force ran" & the only time it didn't was after take 1 on the distributor install. The only noticeable difference now is the high pitched whine / noise in force run was gone and the cranking is extra smooth. Excuse me for asking a ridiculous question, but could the alternator play a potential role in this?
I'm open to all suggested troubleshooting! 
Might want to ohm out the purple/white wire from the icm to ecm pin d8. 
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Ed , I've read your whole thread here twice for good measure and the one thing that stands out to me is this ; 
