Possible bad hei module?
03-16-2008, 10:36 PM
#1
Possible bad hei module?
I have been having a problem of my car just stalling out on me. It would kick back up and go for a while, maybe even 3-4 days. Well one day it happened again so i thought it could possible be fuel. No fuel issues were present. I then thought maf. Maf was fine and i even changed it out just in case.
Anyways I then thought it was my computer when i couldnt even get the car to start. Anyways I installed my Megasquirt while i was down. Now that i have that i did some datalogging in order to get it to start. It showed that I have no rpm signal. I think this could be my problem. I can get the car to turn over once about , but then nothing.
A bad module could possibly give no rpm readout correct?
Anyways I then thought it was my computer when i couldnt even get the car to start. Anyways I installed my Megasquirt while i was down. Now that i have that i did some datalogging in order to get it to start. It showed that I have no rpm signal. I think this could be my problem. I can get the car to turn over once about , but then nothing.
A bad module could possibly give no rpm readout correct?
03-18-2008, 10:56 AM
#2
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Location: West Central Ohio
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Car: 86 vette
Engine: 383
Transmission: 700R4
Axle/Gears: 3.07
Re: Possible bad hei module?
The distributor supplies the spark pulse under 400 rpm. Also sends pulse to ecm for injectors.
Check/change the ignition module.
Check/change the ignition module.
03-18-2008, 09:42 PM
#4
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Car: 86 vette
Engine: 383
Transmission: 700R4
Axle/Gears: 3.07
Re: Possible bad hei module?
No.... Spark will come from the Dis. only, till 400 rpm. You will see your initial (base timing only). After 400 rpm it is ECM controlled (base + ecm timing).
The ignition module puts out pulses, this firers the injectors (through the ecm) and the coil (bypassing the ecm), at 400 rpm and up, ecm controls injectors and spark.
A bad ignition module will not fire either spark, injectors, or show rpm(data log) . Sometimes they just almost work, replace with a known good one.
Some after market will almost work.
New AC DELCO will always work.
To be absolutely sure remove from a running car.
Also use the approved thermo compound. Heat kills electronics.
The ignition module puts out pulses, this firers the injectors (through the ecm) and the coil (bypassing the ecm), at 400 rpm and up, ecm controls injectors and spark.
A bad ignition module will not fire either spark, injectors, or show rpm(data log) . Sometimes they just almost work, replace with a known good one.
Some after market will almost work.
New AC DELCO will always work.
To be absolutely sure remove from a running car.
Also use the approved thermo compound. Heat kills electronics.
Last edited by pandin; 03-18-2008 at 09:47 PM.
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