Hey guys,

My 88 5.7 has been running very poorly after a recent JumpStart that was needed after my uncle gave me a ride and parked it at his house for the weekend.

After a series of diagnostic procedures, I would conclude that the prom chip is not functioning properly, the service engine light will not flash out the codes after jumping pins a and b on the aldl connector, and the car runs the same as I systematically disconnect sensors from the engine. I also happen to have a backup ecm that I tried, as well as verifying the power supply lines to the ecm and the connections from the aldl test terminal to the connection on the ecm...

Additionally, out of curiosity, I turned the car to RUN without the chip plugged into the ecm and the ses light stayed on, as opposed to when it IS plugged in

So my assumption is that the prom is shot. It's actually a hypertech chip put in over 10 years ago by the previous owner,

But as with most diagnosis, I can't be sure until I spend/waste money haha, so if anyone has any suggestions for confirming this diagnosis or further ideas, I'd greatly appreciate it...

Thanks

 

With the ECM swap the prom sounds like it's faulty. Hypertech made several memcals/piggy back units. If it has two small chips or a series of small resistors on a PCb next to the prom it maybe able to be salvaged. The ones with a glossy black substance next to the prom are some how encrypted in the read and as far as I know can't be repaired.

 

It is a glossy back chip, that ic chip is glued/soldered pretty well.

Looks like I'll have to replace it,

Thanks!