Bad ECM? 90 sc 5 speed

Prodigy

Registered User
Been working in my sons 90 Thunderbird sc 5speed. Had a terrible diagnosis on this by me. Thought the timing chain jumped, well after I got it all apart it was fine, actually in great shape for 160000 miles. I'll tell you a quick rundown of what it's doing and what I have tried so far.

He was driving down the road and it just died and he had a friend help him get it back to the house. The first quick checks I did was fuel pressure (40psi), spark (good). Compression good 120 psi. Unplugged cam sensor just to see if it would burp, nothing.

There is no signal to the injectors. Took crank sensor off bench tested, good. Went through the monotonous rundown off checks to check DIS and coil pack.

As I'm working on it I keep asking him has he ever noticed the Cooling fan stays on high with ignition on and fuel pump never shuts off. To me this isn't correct. Fuel pump should only come on for a pre-determined time. Checked the relay control module by taking apart and checking diodes and relays and one transistor, they were good.

I have the ECM apart right now. In circuit all diodes and transistors check good, I have no way of checking the old obsolete Motorola IC's cause I don't have the pin outs. I am leaning towards a bad ECM. Unless someone can steer me differently.

Being that the case anyone have a ECM?

How close do I have to be on the numbers for ecm. On one side FOPF-12A650-ALA, on other side printed in pink E9AF-14A625-AA.

Thanks in advance for your help.
 
Unless you already did this, verify the power and ground connections at the EEC. If it is receiving power on the required pins and ground is good, then 99.9% it is an EEC. Not a common failure, but fan and fuel pump on definitely indicate no signal coming from the EEC to the IRCM. The most basic thing an EEC does is turn off the fuel pump and fan (they run constantly in the absence of a signal to tell them to turn off). So that's generally a dead giveaway of a bad EEC unless the EEC simply isn't getting powered properly.

I have a guaranteed good 90 5spd EEC. Email me at mdkracing@windstream.net if interested in purchasing.
 
Eec

Unless you already did this, verify the power and ground connections at the EEC. If it is receiving power on the required pins and ground is good, then 99.9% it is an EEC. Not a common failure, but fan and fuel pump on definitely indicate no signal coming from the EEC to the IRCM. The most basic thing an EEC does is turn off the fuel pump and fan (they run constantly in the absence of a signal to tell them to turn off). So that's generally a dead giveaway of a bad EEC unless the EEC simply isn't getting powered properly.

I have a guaranteed good 90 5spd EEC. Email me at mdkracing@windstream.net if interested in purchasing.


I sent you an email xr7
 
since you said that you took apart the front to check the timing chain, I assume all is good with the harmonic balancer and trigger wheel?
 
Thanks Dave. EEC worked great start up on first crank. Just out of curiosity how would one go about getting my old EEC flashed/reman so I would have a spare?
 
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