Hello guys I'm new here, I am hoping this forum can help me figure out my problem.

OK from the top, I have a 1990 F350 Ex CalTrans truck, with a 5.8l and a 3 speed auto. When I first got it about a year ago the Check Engine light was on so I bought a Cheapo Scanner from AutoZone (acton) , fixed a TPS. So the other day it dies on the freeway and I am stuck on the side wondering what happened? after a long while it starts and I drive home with a very bad running truck, would not idle at all. The next day I pull out the scanner and try to pull some codes, I get nothing not a blink. So I pulled out the Chiltons and a sweep style volt ohm meter and try that method.... agian nothing. my first guess is the EEC was not getting power, so I backpobe the EEC relay its sending 12 volts to the EEC with key on.

Now it kinda ran... so I would not think the EEC is dead. But im stumped. so i ask for any suggestions on what might be a problem.

Thanks In advance.
Sam

 

What procedures can I do to condemn the EEC-4?

 

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Suggest searching for ignition module and pickup posts - I think this has the module on the distributor body which makes it susceptible to heat effects. Check for procedures from "fefarms" which make simple tests to determine your problems.

From a previous problem discussion try the link.

"I wish to credit fefarms for the PIP info :-)
His post is here for interesting reading.
https://www.ford-trucks.com/forums/s...04#post2571104

Cheers,
Popa Tim"

 

The computer usually doesn't die...they're least likely to be the problem.

I'd check into the TFI module, it's on the drivers fender, and check for fuel delivery problems.

 

Thanks for all the replies. The module is on the side of the distributor, I will ask Fefarms for his input. Now, would a bad TFI cause the EEC not to go into Diagnostic mode? I understand that a computer wont just die, but I have seen just one part of a computer go bad (like an injector driver).

My big concern is with the computer not going into Diagnostic mode!

thanks agian.
Sam

 

Sorry I mistook that you have a 90'. A bad TFI module wouldn't cause the computer not to go into diagnostic mode.

So you're not able to get into diagnostic mode? KOER or KOEO? I just thought u weren't able to get codes...i didn't realise you can't get into diagnostic mode at all...

My 393's computer hasn't gone into KOER mode for me yet, but it'll go into KOEO just fine. Havn't really played with that much though.

You know where your diagnostic plug is, there should also be a 1 wire plug kinda hanging off it too. That is the STI wire. Gound that wire, and turn the key on. You should hear the fuel pump come on then shut off, and some clicking going on under the hood. Then a blip on the engine light, and it should start flashing at you. That would be the KOEO test.