How to test a suspect delco pcm?

Holden/Delco Tuning. ALDL, OBD 1.5. Circa 1989 to 2004.
Charlescrown
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Re: How to test a suspect delco pcm?

Post by Charlescrown »

Noid lights are handy but any test light will do. You can actually read the light when you look at the flashes to get an idea just how much fuel is going in.
VTXU8
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Re: How to test a suspect delco pcm?

Post by VTXU8 »

Well i'm totally lost. Noid tests showed injectors are getting a good pulse. Spark is good too. tested fuel pump for flow and thats good. so whats left? PCM would seem operational too. Would a bad Hall Effect Sensor cause it not to start even tho everything else seems fine?
Charlescrown
Posts: 1831
Joined: Sat Aug 06, 2011 7:58 am
cars: V8 VR Commodore BT1
LB Lancer 2L turbo & Delco
Starion TBI with Delco
Mitsubishi Lancer EVO4 track car
NA MX5
3 vintage motor bikes
Location: Padstow NSW

Re: How to test a suspect delco pcm?

Post by Charlescrown »

Injector pulse and spark says it should go or at least try. Try another set of plugs or at least heat your old ones up with a Butane torch. The problem with modern plugs is the Porcelain is very porous to prevent cracking over a long life not like the old cars that at best got 10,000kms life span. Worth a try before ripping your hair out.
VTXU8
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Re: How to test a suspect delco pcm?

Post by VTXU8 »

Charlescrown wrote:Injector pulse and spark says it should go or at least try. Try another set of plugs or at least heat your old ones up with a Butane torch. The problem with modern plugs is the Porcelain is very porous to prevent cracking over a long life not like the old cars that at best got 10,000kms life span. Worth a try before ripping your hair out.
Thanks, i will try that. I'm willing to try anything at this stage
VTXU8
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Re: How to test a suspect delco pcm?

Post by VTXU8 »

Update: Replaced fuel pump/filter, flushed whole system, flow tested injectors. Fired and started for 1 second but thats it. Only thing left is dizzy which i will be replacing tomorrow. If that dont work it can only be one thing...the PCM. I can't find a 304 vt manual PCM i can only find auto PCM. I have asked on here if you can use an auto pcm on a manual car but all ive gotten so far is crickets. This whole thing is driving me nuts. It has cost me an absolute fortune and still nothing :rant:
Charlescrown
Posts: 1831
Joined: Sat Aug 06, 2011 7:58 am
cars: V8 VR Commodore BT1
LB Lancer 2L turbo & Delco
Starion TBI with Delco
Mitsubishi Lancer EVO4 track car
NA MX5
3 vintage motor bikes
Location: Padstow NSW

Re: How to test a suspect delco pcm?

Post by Charlescrown »

I don't think the plugs are the same with the auto ECU. Really the ECU is the last thing but yes they do fail.
VTXU8
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Re: How to test a suspect delco pcm?

Post by VTXU8 »

Yeah you're probably right. I just found a local mob who do repairs/cloning pcms. so if dizzy dosent fix this issue then it can only be the pcm. I have had one go on my vp v8 before but that was an easy diagnosis due to injectors constantly pumping fuel with just the ignition on.
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delcowizzid
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Re: How to test a suspect delco pcm?

Post by delcowizzid »

Vt v8 ecu is the same manual and auto just a different tune. My guess is your plugs are fowled or the dizzy is dead or has spun around out of time or maybe the nvram has a setting that's corrupted have you tried reburning it with an earlier tune in a programmer
If Its Got Gas Or Ass Count Me In.if it cant be fixed with a hammer you have an electrical problem
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delcowizzid
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Re: How to test a suspect delco pcm?

Post by delcowizzid »

Or the maf taken a shit or hose split
If Its Got Gas Or Ass Count Me In.if it cant be fixed with a hammer you have an electrical problem
VTXU8
Posts: 93
Joined: Sun Dec 17, 2017 9:12 pm

Re: How to test a suspect delco pcm?

Post by VTXU8 »

delcowizzid wrote:Vt v8 ecu is the same manual and auto just a different tune. My guess is your plugs are fowled or the dizzy is dead or has spun around out of time or maybe the nvram has a setting that's corrupted have you tried reburning it with an earlier tune in a programmer
Thanks Delco, That' what i thought. Nvram im sure is good, I fitted my old memcal and it did not work either. I have a new dizzy to go in just not looking forward to doing it. I have removed and cleaned plugs( replaced not too long ago).
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