Really need help with the last small issue with my 90

[XfireZ51]

If that was ur first start after unplugging IAC, the 2000rpm zoom was the reset.

[Corvette95]

XfireZ51... I paraphrased on my response as to the procedure but I printed out and followed your steps exactly as written other than not setting the idle quite so high. I did the 2000 RPM set after I reconnected the battery and adjusted TPS to .54 (.56 gave me a 1% thottle angle reading). Shut the motor down and it idles about 75 rpm higher than before but the main thing is I have a 1 IAC count at idle where is was zero count before warm in closed loop. Thanks for the tips, I don't know if that will fix it but I appreciate the help. Expect and update from me tomorrow. I also may have found a dealer with three ECM's in stock, I have them looking for them right now, if they do, I am going to snag one of them! ( I also had previously changed the idle adjustment screw to an 8mm, so I had that going already! )

[Subfixer]

Originally Posted by Corvette95

I also may have found a dealer with three ECM's in stock, I have them looking for them right now, if they do, I am going to snag one of them!

If they have 3, get all of them. I'll be in for one if you get them.

[Corvette95]

FYI, I have had ten people PM me about the ECM's so IF they end up even having any, they seem to all be spoken for. Sure looks like an aftermarket opportunity for some company!

[Corvette95]

So no word on ECM's yet. Today was the first day after the minimum idle adjustment and IAC reset for a cold start. Did the same thing, started, fired up, stumbled .... but I tried to see if I could "catch it" with throttle before it died and I was just able to. The following is the IAC counts at cold start up and stumble and with me giving it throttle to prevent stall.... now what? Thanks! https://vimeo.com/448956933

[Ccmano]

After looking at your video, your car is taking too much cranking time before it starts. These cars do have a long crank time, especially when cold, but not that long. Based on the video it took 7-8 seconds of cranking. Thats about twice as long as what I would consider normal.

Please try something for me. Tomorrow morning, get in the car and turn the ignition but don't start the car. Wait until you hear the Fuel pumps stop running. Once the pumps stop turn the key the final amount to crank the car. I want to see if it still takes as long and if it has an impact the stumbling. If nothing else this should eliminate fuel as an issue.
H

[Corvette95]

Originally Posted by Ccmano

After looking at your video, your car is taking too much cranking time before it starts. These cars do have a long crank time, especially when cold, but not that long. Based on the video it took 7-8 seconds of cranking. Thats about twice as long as what I would consider normal.

Please try something for me. Tomorrow morning, get in the car and turn the ignition but don't start the car. Wait until you hear the Fuel pumps stop running. Once the pumps stop turn the key the final amount to crank the car. I want to see if it still takes as long and if it has an impact the stumbling. If nothing else this should eliminate fuel as an issue.
H

Hey! I will try anything (what so you want video of while cranking..fuel pressure gauge readings, IAC , readings or anything else?). Todays crank/start took much longer than previous days. It may be related to the minimum air adjustment and IAC reset of yesterday. I will try your test but I am getting both pumps initially on to 51+ psi then drop to mid 40 and holding there during crank...I was going to video it again but tried to keep the clip short. I just replaced the two new Airtex pumps Monday with two new Delphi Pumps. I can energize the second fuel pump with both the Tech1 and the test lead off the harness near the battery so I know both pumps are working (and psi goes back to 50+ - even tried cranking with Fuel pump lead energized-no difference). New FPR from Phil. I am open to any and all suggestions (Marc H has been helping me on the side as well). I will post the start sequence tomorrow. In the back of my mind, when I caught it from dying this morning with throttle , it backfired a little...again, no intake or PCV leaks . And when it starts it runs fine. I dont see how but could this be a coil or spark plug wire issue because it RUNS SO WELL after it starts the second time. Full power mode fine, no codes. Did you notice a 173 IAC reading??? I didn't think it would read over 150??? I am going to reset the min idle back to prior position and do another IAC relearn. Should have done that today but didn;t have time. I also am going to pull the plugs and examine them, it has a constant rich reading on the BLM but that would only help a cold start? Idle after closed loop was 725-750 with a 0 to 1 IAC count. The only thing I have not reversed is the oil catch can addition. I was told the PCV system would not affect the starting regardless. I have the oil catch can plumbed from the left vent tube at read of engine to a catch can below or beside the brake booster and the line in to the PCV dual adapter. It looks really good (IE hidden) as long as it is not a problem. Tank was clean when I got it but I completely drained the tank cleaned every spec of debris out of it before I put the Airtex pumps in with fresh 91 octane non ethanol gas. I found a NOS correct from factory IAC valve I ordered yesterday, I am going to try that too when it arrives this weekend. I also did an injector (primary) balance test, all injectors are working plus I did a rail check for drips and spray..all test good. I am twice over budget on this car, really three times over so I did use Bosch injectors. (all 16) and new orings.

[Corvette95]

I called about the ECM, they said it still had a ticket on it, I would hear shortly. ANYWAY, I got my TunerCat Datacat software and cable in. This is something I have NEVER done. I have always used Tech1 and Tech2 (and now Autel and G-Scan3). What do I need to set to record the data you need to see with my 90's start up issues? I assume just set it to record when I start it, then I assume I find the recorded file and post the file here on the Registry? Anyone know what the file extension is? Thanks

[Corvette95]

While not being able to sleep at 1:14 am. I am likely going to pull the plenum soon and do a visual...I am going to replace the coils and re ohm the wires. I was also reading back through OLD tech articles and I saw this post
"Pull the water seal on the DIS plug back, I guarantee you one of the pins is pushing out when you install the plug, with the water seal pulled back you will be able to tell which pin it is within seconds. I don't remember if these pins are 100 series or not, They are easy to change if needed.
Don't cut or shorten the wire, Take your time and open the crimp connection. Sorry to tell you but the tool is special and a good GM terminal tool is going to cost you about $100.00." Now I know to look for bent pins on the DIS module, thats a given, but not quite sure about this post, does it refer to the DIS harness connector- is there a known issue with the plug itself? Not sure what is meant by one of the pins pulling out. I would want to check this as well, I assume it is a standard metric weatherpack terminal?
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[Ccmano]

Originally Posted by Corvette95

While not being able to sleep at 1:14 am. I am likely going to pull the plenum soon and do a visual...I am going to replace the coils and re ohm the wires. I was also reading back through OLD tech articles and I saw this post
"Pull the water seal on the DIS plug back, I guarantee you one of the pins is pushing out when you install the plug, with the water seal pulled back you will be able to tell which pin it is within seconds. I don't remember if these pins are 100 series or not, They are easy to change if needed.
Don't cut or shorten the wire, Take your time and open the crimp connection. Sorry to tell you but the tool is special and a good GM terminal tool is going to cost you about $100.00." Now I know to look for bent pins on the DIS module, thats a given, but not quite sure about this post, does it refer to the DIS harness connector- is there a known issue with the plug itself? Not sure what is meant by one of the pins pulling out. I would want to check this as well, I assume it is a standard metric weatherpack terminal?
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I've had this happen to me. It usually throws a code, depending on which pin is misaligned. If you pull the rear DIS connector and look in on the pins of the DIS you will see a bent pin if that is the case. Sometimes a pin will go next to the connector instead of through it causing an intermittent condition. In this case you'll see the pin only slightly bent to one side or the other. The metal connectors tend to float a bit within the plastic causing this. Highly unlikely this is what is causing your issue.
H