Fried another ecm

[mccoy1990]

i have been through two ecms, if you replace the ecm, the car will start and run until you fry another one. Currently i have a 1990 non-turbo ecm in it, the car runs but at 5200 rpms the fuel flow is restricted, any suggestions?

 

[steve]

What exactly are you frying?

I either see ISC drivers blowing and they will continue to blow until the fix the problem or caps leaking an taking out the ECU.

Running an N/T ECU is a non-option.

Steve

 

[MyTGSX]

This is from something else, but have the Alt. checked for AC current, sometimes when an Alt. goes bad it's still putting out 13+volts DC but it can push AC into the system also, which can fry electronic parts. My old 94 Formula had a bad one(tested 2.5V AC when warmed up) and it fried almost all my sensors, and I went through 3 PCM's before I found it. The Autozone alt tester can test it in car.


There is some talk in other auto relms that as little as 2 volts of AC can fry parts in a car.
This is also a cumulative damage, took me around 2-4 weeks to fry a PCM.

 

[mccoy1990]

the ISC drivers are frying, i need to figure out why

 

[steve]

the ISC drivers are frying, i need to figure out why

If you have searched the archives you would know that the typical cause is a bad ISC.
Any shorted windings will fry the driver in microseconds. If the winding resistance is much below the spec of 28ohms damage can happen.

Both the VFAQ site and Stealth316 have the procedures for checking the ISC.

Steve

 

[oldman]

After you check the isc, steve would be the person to send your damaged ECUs to.