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Old 08-05-2010, 06:13 PM   #1
ChickenRammit
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symptoms of bad ESC module or ignition control module?

i've recently done a TBI and manifold swap on my '86 350. i'm having some issues that i can't quite figure out.

its having some serious detonation issues after the engine is warmed up. i replaced the EGR valve and solenoid with no improvement.

there are no codes to speak of.

I'm wondering what the engine would act like with a bad Electronic Spark Control Module?

I'm also wondering how the engine would act with a bad Ignition Control Module?

thoughts? opinions?
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Old 08-09-2010, 07:01 AM   #2
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Detonation? You mean pinging? Although you are useing the proper term I don't hear many people use it anymore.

I have never seen a ESC go bad. Doesn't meen it can't happen but I wouldn't know what to say it does or doesn't do.

The EST in the distributor is the only gremlin on these systems as it will test good then run bad. Auto parts stores can check them. Ask them to check three times. If it fails any, it's bad.

Did you disconect the timing wire to set timing at 0 at idle? What is the timing at idle when reconected?
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Old 08-09-2010, 07:08 PM
Posted in reply to eagle mark's post starting "Detonation? You mean pinging? Although..."
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hey eagle thanks for the response.

i set the timing to 0 degrees with the bypass wire disconnected. i will check it again with it connected and get back to you on that.

one other thing that may be worth mentioning, is that i eliminated the A.I.R. components. there use to be a double vacuum line coming off the throttle body. one line went to the egr and one went to the AIR valve.

right now, i just have one line going to the egr, and the one that use to go to the AIR valv is plugged off.

is it possible that there is now too much vacuum pressure going to the EGR solenoid and throwing off the performance of the EGR system?
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Old 08-09-2010, 07:23 PM
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Disconect the EGR and see what happens.

The EGR allows a little exhaust gas to enter the combustion chamber at certain times to reduce a nasty pollutant (forgot what it's called) the exhaust gas kept the cylinder temps down causing the nasty pollutant to not happen. But there was no loss in power because now you can raise timing now... so timing tables were very differant between EGR and non EGR motors. This may very well be your issue as EFI vehicles EGR is controlled by the ECM and your 86 was not.

And please tell me your not running gas that was in the tank of a project truck that has been sitting for 10 years?
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Old 08-19-2010, 05:30 PM
Posted in reply to eagle mark's post starting "Disconect the EGR and see what happens...."
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ok so if i disconnect the egr, where do you think would be a good place to set the ignition timing? should i advance it more?

also i've been using new gas. i have a brand new gas tank from an efi blazer with fresh gas.
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