Won't stay running..

Have a flashing light? Gauges acting funny? Bad idle? Get your problems solved...
GT_Indy
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Re: Won't stay running..

Postby GT_Indy » Fri Oct 06, 2017 11:32 am

That's good. Usually the ECM doesn't go bad but they can. Just remember to swap the eeprom to the new ecm.
I think a general tune up might help it if its overdue on anything. Plugs, wires, coils test, IACV, throttle body cleaning, fuel filter, etc.
(Edit: Misread icm for ecm. The icm can go bad as its bolted on the side of the engine block)
Last edited by GT_Indy on Fri Oct 06, 2017 4:40 pm, edited 1 time in total.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

Bapsu
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Re: Won't stay running..

Postby Bapsu » Fri Oct 06, 2017 2:43 pm

Mm, dont think is ECM since the spark is cutting, I would more suspect ECM if it would have problems with having stable idle or sth. Just ordered new plugs and wires from rockauto yesterday, still gotta get icm somewhere, I dont wanna buy that 120€ AcDelco unit from Rockauto.

What is IACV? You mean IAC valve? I cleaned that valve on spring when I tried to sort out the hard start. It helped and the car started starting as it should. The intresting part comes here: When i cleaned iac, I unplugged battery. After cleaning, I did not do idle relearn and the car worked well (except misfire ofc). After 2 weeks, I decided to do the idle relearn; hard start came back? After that I was like wtf and tried cleaning and checking iac again, without success. Its been hard starting since july when I did the idle relearn. Damnit. Could it still be iac?



GT_Indy
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Re: Won't stay running..

Postby GT_Indy » Fri Oct 06, 2017 4:37 pm

Yes I put IACV for IAC valve. lol

IAC valve can get weak spots causing idle issues, usually they fail causing one of two things: high idle or super low idle where you need to keep your foot on the gas to keep it running or it will stall.

Spark cutting would lead me to look at the ICM, CPS, coils, wires, and plugs. If you can see spark cutting out and fuel pressure tests okay, I'd look into the ignition side.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

Bapsu
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Re: Won't stay running..

Postby Bapsu » Sat Oct 07, 2017 2:50 pm

Yeah it must be ignition side.

And yea, no wonder icm is blowing up since someone genius decided to put it right under exhaust manifold.

I'll head to the store monday and ask for used icm and coils pack . Not gonna buy new ones as I am not 100% sure about the culprit for misfire.

Its just one hell of a pain in ass to remove the fan lol.



GT_Indy
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Re: Won't stay running..

Postby GT_Indy » Sat Oct 07, 2017 8:39 pm

Bapsu wrote:Yeah it must be ignition side.

And yea, no wonder icm is blowing up since someone genius decided to put it right under exhaust manifold.

I'll head to the store monday and ask for used icm and coils pack . Not gonna buy new ones as I am not 100% sure about the culprit for misfire.

Its just one hell of a pain in ass to remove the fan lol.


Yah, I usually remove the intake then lift the fan after I unplug it.
There is a write up on here somewhere for relocating the ICM/coil pack assembly, I forgot where.
Some auto stores will test the ICM for free, I'd have them run it on their tester a few times in a row to see how it works when it heats up. Usually they start failing after the 3rd run when they start heating up, at least in my experience.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

Bapsu
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Re: Won't stay running..

Postby Bapsu » Mon Oct 09, 2017 10:03 pm

Yeop. Bought used ICM+coils for 70€ today, can return if doesnt seem to work. I'll install next week when got time. Misfire better disappear with that! :deadhorse: Lets see how many days it gets from rockauto to ship their stuff here... Damn im jealous to ur guys living at usa... U dont need to buy 20€ postal expenses and taxes for 20€ stuff. Its almost free for u to keep up ya cars there. :(

Part is from -95 Lumina tho, there ICM is installed to other place than under exhaust, so it might be in much more better shape than corsicas / berettas modules.. Or then not. At least they said it was ok before they took everything worth of selling out of the car.



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Re: Won't stay running..

Postby GT_Indy » Tue Oct 10, 2017 1:51 am

I hope it works out for you.

As far as I know any ICM and coil assembly from any GM vehicle that has a 2.8, 3.1, 3100, or 3400 should be interchangable. I haven't had issues with my cars doing that and I have swapped them many times in the past.

We may have free shipping on stuff but quality is poor. Many things are imported from countries with little to none quality control. Products are made here, but not as many as they could be making.

A good example is my My 87 Cadillac's alternator. I went through 1 alternator a day on a life long exchange policy for an 80 dollar new replacement 105 amp alternator.
They were failing within 10 miles of driving. 1 was actually dead out of the box as I started having the stores test the replacements before I accepted them.
A week later I bought a made in USA 150 amp quality alternator from Summit racing for like 250-300 dollars. Never had problems again.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

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Re: Won't stay running..

Postby ifixalot » Tue Oct 10, 2017 10:27 am

"When i cleaned iac, I unplugged battery. After cleaning, I did not do idle relearn and the car worked well (except misfire ofc). After 2 weeks, I decided to do the idle relearn; hard start came back? After that I was like wtf and tried cleaning and checking iac again, without success. Its been hard starting since july when I did the idle relearn. Damnit. Could it still be iac?"

Pull the battery cable again, let it sit and lose idle memory and see if it starts easier. If it does, I'd bet you have one or more bad injectors. My theory, is the ECM riches the mixture based on the oxygen sensor to compensate for the lean condition caused by one or more injectors not passing any fuel. Then it remembers that setting when the engine is cold. You then have most of the cylinders running rich and one or two still running lean. When you lose that memory, the ECM defaults back to a setting that fire all injectors on some programed data which gets the majority of cylinders firing properly again except for the ones with a bad injector.



Bapsu
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Re: Won't stay running..

Postby Bapsu » Wed Oct 11, 2017 9:32 pm

ifixalot wrote:"When i cleaned iac, I unplugged battery. After cleaning, I did not do idle relearn and the car worked well (except misfire ofc). After 2 weeks, I decided to do the idle relearn; hard start came back? After that I was like wtf and tried cleaning and checking iac again, without success. Its been hard starting since july when I did the idle relearn. Damnit. Could it still be iac?"

Pull the battery cable again, let it sit and lose idle memory and see if it starts easier. If it does, I'd bet you have one or more bad injectors. My theory, is the ECM riches the mixture based on the oxygen sensor to compensate for the lean condition caused by one or more injectors not passing any fuel. Then it remembers that setting when the engine is cold. You then have most of the cylinders running rich and one or two still running lean. When you lose that memory, the ECM defaults back to a setting that fire all injectors on some programed data which gets the majority of cylinders firing properly again except for the ones with a bad injector.
Well, thats one theory.

I noticed, that when I was doing the idle re-learn (did once or twice after july, didnt help) the car started just fine [b]during[b] the relearn (u gotta start the car twice during the learn, right) but right after relearn was completed, it started hard starting again. :ROFL:

Lets see what it thinks about new icm and coils first, I guess bad icm can cause hard starts also if its not functioning properly.



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Re: Won't stay running..

Postby GT_Indy » Thu Oct 12, 2017 9:56 am

To much or a lack of fuel can cause a hard start as well.
A fuel pressure tester can rule that out or show if its an issue.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

AeraBell
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Re: Won't stay running..

Postby AeraBell » Sat Oct 14, 2017 12:29 pm

I'm trying to fix mine. I replaced tps, crank position sensor, map sensor, plugs, wires, tested the fuel, changed fuel filter and it still dies less than ten seconds after turning it over... I don't have a fuel pressure gauge to test.. any ideas?



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Re: Won't stay running..

Postby AeraBell » Sat Oct 14, 2017 12:31 pm

Also the pump primes the system but we don't think it works after turning it over.. how can we test the pump without the car running (since it doesn't)



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Re: Won't stay running..

Postby GT_Indy » Sat Oct 14, 2017 8:45 pm

AeraBell wrote:I'm trying to fix mine. I replaced tps, crank position sensor, map sensor, plugs, wires, tested the fuel, changed fuel filter and it still dies less than ten seconds after turning it over... I don't have a fuel pressure gauge to test.. any ideas?


Just to verify, you replaced these with new?
TPS
CPS
MAP
Plugs
Wires
Fuel Filter.

What did you see when you tested the fuel pressure? Number in PSI?

Possible things to check:
Does the Fuel pressure remain consistent after starting and running and after stalling? Or does pressure drop off?
Spark: Does the engine still spark after stalling? Or does the spark stop working causing it to stall? (Spark tester)


AeraBell wrote:Also the pump primes the system but we don't think it works after turning it over.. how can we test the pump without the car running (since it doesn't)


If your fuel pressure holds about 45 PSI consistent and doesn't drop, then possible causes could be the ICM or a fuel injector, or multiple injectors. Depends on if your spark tester shows good spark or failing spark.

You said 91 Beretta? Is it the 3.1 v6 auto?
I like the 3.1 MPFI v6 engines, not much to go wrong on them when something does need replaced.


Mint White 1990 Beretta GTZ Quad4 5-spd
Mint Yellow 1990 Beretta Indy 3.1 auto, Digital Dash, Sunroof.
Clean 1996 Beretta (Z26 swap) 3100 auto.

AeraBell
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Re: Won't stay running..

Postby AeraBell » Sat Oct 21, 2017 5:53 pm

Just put a new fuel pump in it too and it's still isn't staying running...



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Re: Won't stay running..

Postby AeraBell » Sat Oct 21, 2017 5:55 pm

It's the 3.1 91 yes. I replaced all of those parts I'll have to test the injectors next




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