First time poster long time stalker, sorry if this isn't the correct thread but I'm desperate. Is this ECM problematic looking? 1987 F150 4.9 manual transmission.

Longer story is that maybe a week or two ago I has one morning a long crank before start, and it did the same thing later that day. Checked for fuel at the scrader valve, there was fuel. Ran a fuel gauge and engine off, the 4.9 showed high FP (for every model except 1987 this pressure was normal). Ran fine until while driving RPM dropped to 0, then they rose right back up and kept driving.
Ran fine for a week after that until yesterday when it died while driving.

I just replaced rear in tank Fuel Pump, in-line fuel pump, fuel filter, and TFI module.
Got it to fire and run for a minute or two with foot on pedal to idle it (it sometimes has an issue with staying alive while cold, closed loop issue?). Now there is no power at the rear fuel pump, and there's one wire on a really under the hood that reads 3.5V. When 12V is applied to that the pumps run.

Mobile mechanic suggested checking ECM but trying to find a suitable replacement is difficult and I'm trying to find if any are compatible, or if I must acquire the same ECM or have it rebuilt.


Long story but hopefully that and the pictures help. Any advice appreciated. I've posted on three sites now and I'll keep digging.

 

It looks like that truck or the ECM was under water as there is a lot of badness in there.
Yes get new one check with the local parts stores with the trucks info, may need the VIN and the number off the ECM and see what they got.
Dave ----

 

Although I have plowed through some puddles, the West Coast salty air is probably the culprit here.
I had a difficult time finding a compatible replacement from the auto stores around here. As much as I despise it, I asked Chat GPT to find me some compatible ECU. I have one on order.
In the meantime with help, we bypassed the EEC Relay by applying power directly to the red wire. Drove it around the block a couple times and it seems to work.

Thanks for the response

 

It may or may not be the problem but from what I see that is where I would start as all that green stuff and dirt, etc. cant be good
Keep us posted as it may help others down the road.
Dave ----

 

New ECM from AutoECMS arrived today and I just installed it. Truck starts up and idles fine. Haven't drove it but I'm sure It'll be alright. I was hoping this would fix some other issues like my blower motor when turned on heating up one specific ignition wire . But it turns on and idles and both relays are now plugged into the ECM.