PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

98 PCM Bad?

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Old Aug 7, 2012 | 12:09 AM
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Default 98 PCM Bad?

OK im kinda lost here with this car i just bought... It is a 6.0 with 243 patriot heads. Theres fuel and theres spark but it doesnt start. Vats are deleted, Cam Position and CRank position sensors are both new but it just doesnt start and smells really rich. What you all think it could be? Bad PCM? Im not sure whats missing. Please help with this headache
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Old Aug 7, 2012 | 11:09 AM
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Originally Posted by frankmarroquin
OK im kinda lost here with this car i just bought... It is a 6.0 with 243 patriot heads. Theres fuel and theres spark but it doesnt start. Vats are deleted, Cam Position and CRank position sensors are both new but it just doesnt start and smells really rich. What you all think it could be? Bad PCM? Im not sure whats missing. Please help with this headache
More info needed. Did the car run when you bought it, or did you buy someone else's headache? If it did run when you bought it, how well did it run. Did the the no-start condition just recently happen? Did the car seem to have any issues leading up to the current problem?
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Old Aug 7, 2012 | 01:26 PM
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Sorry, i bought it not running. I Did a compression text and everything checked out fine.
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Old Aug 7, 2012 | 02:37 PM
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So from what you're describing, sounds like it's dumping fuel. Any codes being thrown? Also, since it was not running when you bought it....what did the previous owner say happened?
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Old Aug 7, 2012 | 03:41 PM
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The previous owner said it was running fine then one day it just stopped. I flashed the CPU and its a completely stock file. And yes its flooding the cylinders. Till i forgot to mention that i charged the oil and i noticed there was gas in there too. And i also checked the timing dots and they were aligned perfectly.
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Old Aug 7, 2012 | 03:49 PM
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Originally Posted by frankmarroquin
The previous owner said it was running fine then one day it just stopped. I flashed the CPU and its a completely stock file. And yes its flooding the cylinders. Till i forgot to mention that i charged the oil and i noticed there was gas in there too. And i also checked the timing dots and they were aligned perfectly.
Ported heads, and a stock tune file? Interesting.

Any trouble codes showing? That's the next logical step. Also, what's the coolant temp sensor reading when you scan it?
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Old Aug 7, 2012 | 08:27 PM
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Check that the TPS is not bad and telling the PCM that the throttle is open - could be fooling the PCM into dumping the fuel in.

Also, unplug your MAF and see what happens

Bird
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Old Aug 8, 2012 | 12:09 AM
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Hook a pressure gauge. Open the ignition key and let the pump prime. Don't crank it.
With key still open, watch if the fuel pressure goes down. If it does, you may have leaky injectors, bad wiring or faulty PCM.
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Run a scan with the key on and the engine not running to check TPS, MAP, ECT and IAT.
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Old Aug 11, 2012 | 10:43 PM
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Wow... I feel stupid lmao. PROBLEM SOLVED I just need to tune it now. I was going to start parting it out till i got the motor half way out and found the problem.


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Old Aug 11, 2012 | 10:44 PM
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Thanks everyone for the help...
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Old Aug 11, 2012 | 11:50 PM
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Sweet mother of god......looks like Stevie Wonder was doing the wiring.....

Glad ya found the problem....now get it sorted out and hit the streets!
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Old Aug 12, 2012 | 12:11 AM
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Thanks and yes hopefully i get time to tune it tomorrow.
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