Ignition Module Problems, Revisited
Thread Starter
Junior Member
Joined: Aug 2004
Posts: 15
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From: Canton, MI
Car: 1970 El Camino
Engine: ZZ4 TPI Powercoated Black, SLP Runn
Transmission: LS1 T56, Moser 9" 3.25 Posi
Ignition Module Problems, Revisited
I posted awhile back with an ignition problem where I was losing all timing control. I assumed that because my Accel Gen6 system was left on with the car off for over 10 hours that the timing circuits in the module had burned up from the system being left on. So, I bought a brand new GM module (the $80 one) yesterday and installed it tonight. Before I left, I checked the timing (cold start) and read 20 degrees at idle, which is exactly as programmed into my timing map. I got no more than 2 miles before the same symptoms showed up: low RPM stumble, violent bucking at some RPMs (generally ~1600-1800), and poor idle.
Once I got back, I checked the timing with the light, and sure enough - 10 degrees at idle, then the module pulls timing out to pretty much 0 degrees from about 1000 to 1400 RPM or so, then the timing starts to come back in before jumping back up at a (currently) unknown RPM. Has anyone seen this happen?
I'm running a Mallory VI-AL box and an Accel coil. I'm going the check it again in the morning to see if it is just a heat related problem, in which case I'll be mounting the module externally and with a fan. Any ideas???
Help!
Ryan
Once I got back, I checked the timing with the light, and sure enough - 10 degrees at idle, then the module pulls timing out to pretty much 0 degrees from about 1000 to 1400 RPM or so, then the timing starts to come back in before jumping back up at a (currently) unknown RPM. Has anyone seen this happen?
I'm running a Mallory VI-AL box and an Accel coil. I'm going the check it again in the morning to see if it is just a heat related problem, in which case I'll be mounting the module externally and with a fan. Any ideas???
Help!
Ryan
I'd be more inclined to think this is a problem with the aftermarket ignition box than with the factory module, if I had to take a guess.
Diagnostics: Disconnect the ignition box and run it just like stock for a while to see if the same problem still crops us. If it does, it's something in the factory electronics. If it doesn't it's the ignition box.
Diagnostics: Disconnect the ignition box and run it just like stock for a while to see if the same problem still crops us. If it does, it's something in the factory electronics. If it doesn't it's the ignition box.
Thread Starter
Junior Member
Joined: Aug 2004
Posts: 15
Likes: 0
From: Canton, MI
Car: 1970 El Camino
Engine: ZZ4 TPI Powercoated Black, SLP Runn
Transmission: LS1 T56, Moser 9" 3.25 Posi
I think I may end up trying that. It ran the same this morning, so it's definitely not a heat issue. I'm concerned, though, that the module may already be bad if the box fried it, so I'd have to pick up yet another to try. Hopefully I can get one of the parts places to take one back or exchange it.
Thanks,
Ryan
Thanks,
Ryan
Thread Starter
Junior Member
Joined: Aug 2004
Posts: 15
Likes: 0
From: Canton, MI
Car: 1970 El Camino
Engine: ZZ4 TPI Powercoated Black, SLP Runn
Transmission: LS1 T56, Moser 9" 3.25 Posi
So this morning, the car would not start with the GM module. Went back to the old cheap one and the car starts. Seems I got a dud from GM, which might explain the lack of timing control. I'll try the dealer and hopefully they can either refund my money or give me another one. What a mess...
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Joined: Jul 2002
Posts: 231
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From: Randleman,nc
Car: 87 BUICK GN
Engine: 3.8 TURBO
Transmission: 200R4
modules
hey guys
if you keep having a problem with the car smoking ING modules check the Fuel Pump relay. i used to have a 88 TBI car and it went thru 2 modules and a pick-coil. and then one day i was driving the car and the check engine light came on and the code was Fuel pump voltage low. and it turned out the relay was bad and later on down the road 2-3 k miles later the Fuel pump went bad .
and i think the ECM checks Fuel pump voltage from the Dist.
if you keep having a problem with the car smoking ING modules check the Fuel Pump relay. i used to have a 88 TBI car and it went thru 2 modules and a pick-coil. and then one day i was driving the car and the check engine light came on and the code was Fuel pump voltage low. and it turned out the relay was bad and later on down the road 2-3 k miles later the Fuel pump went bad .
and i think the ECM checks Fuel pump voltage from the Dist.
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