viperjesse

Hi everyone, I'm posting for a friend here.
He bought a 1982 that had hot starting problem, he replaced the ECM last fall with one from PepBoys. Didn't fix the problem. He parked it for the winter with the new ECM sitting loose on the hump beside the battery with a 12 gage ground wire attached. Battery died so he charged it, it wouldn't take a charge so he replaced it. Then no fuel pump noise so he replaced that. Now there is no power to either the injectors or fuel pump. We checked all fuses and connections, all good. We ran codes on ECM and it doesn't even give the 12 code, just lights up the "battery" light on dash and doesn't flash at all.
Could he have fried the ECM?
Lights horn etc. work just now voltage to the pump and injectors.
Any and all help is greatly appreciated.
JZ

tak82

Anything is possible. but first things first, what was the original problem that the ecm had to be replaced , should start with that issue.

hugie82

Did he install the hot wire coming off the starter? I would start with the original problem first and get it cranking. 82 oil pressure sensor will not let the car start if it doesn't see oil pressure. Turning the key to the run position will make the injectors pulse 2-3 times and that's it until it sees oil pressure or if the key gets cycled again.
After the starter is fix move on to the fueling problem.
If you get no pulses from the injectors from cycling the key, then the system is not powered up. Check fuses, grounds and ECM connections.

viperjesse

Thanks guys. The car started and ran fine after the new ECM was installed (and sitting on the compartment hump). The "no power to fuel pump or injectors" began after the battery died, attempted to recharge, then a new one installed.
The injectors do not pulse and there is no voltage to them .Fuel pump was replaced but still makes no start up noise.

dugsgms74

Sounds like a power supply problem, PCM does not give power to the injectors, they receive key on power and the PCM grounds them to turn them on. Get a wiring diagram and make sure the power side circuits are OK.

jdp6000

When you say you checked all fuses you did check the fuse for the ECM in the battery compartment? Don't just check the fuses, replace them even if they look good. Make sure there is no corrosion on the contacts.

Sounds like multiple failures. Depending on what you used to charge the battery "yes' you could have fried the ECM. You should always disconnect the battery when charging it.

hugie82

you have that heavy gauge wire mounted on the back wall of the battery compartment. If the fuse burned or sometimes that wire gets damaged installing the battery.

74 LS4-454

It does sound like you have other issues as mentioned. Go through the "sticky" in the NO START CONDITION(S) SECTION, hopefully this get you started once again......good luck........Tom

viperjesse

OK, after all this diagnosing, my friend informed me that his 25 year old volt meter was not working when we checked for voltage.
Turns out when he replaced the fuel pump last week he got a faulty one from the auto parts store.
Thanks everyone.

hugie82

I'm glad it was an easy fix! These cars are extremely reliable as long as no one or critter hacks up the wiring. Everything else is basic.