efi gremlin

[yakelys69]

A9, 89 efi setup. Twice in the last week while driving my engine (spark) just died momentarily then kicked back on. Sunday it died (no spark) and would not restart. Strangely when I turn the key "on" the fuel pump normally will run for a few seconds then stop as it should, but now the pump just keeps running. If I continue to start the engine turns but no spark. After a while of fiddling around looking at connections I turned the key back to "on" and the pump acted as it should shutting off after a few seconds and the engine started up.

My question is if anyone has a clue as to what wire I may want to track that could possibly cause this or if this is a sign of a computer issue.

 

[Sabas]

Have you run codes??

Sabas

 

[Viperwolf1]

ECM pin #22 (to the fuel pump relay) gets grounded in the ECM to run the pump. It also goes to the self-test connector. A short to ground in that wire would cause that problem but it shouldn't affect ignition. I'd suspect the ECM or multiple wire chaffing problems.

 

[yakelys69]

Thanks Viperwolf, any method of testing an ECM? Sabas I did run codes and nothing out of the ordinary. Chaffing is a definite possibility with those 20 year old wires & shakers. Really wanted to get the font suspension setup b4 rewiring the efi.

 

[Viperwolf1]

Thanks Viperwolf, any method of testing an ECM? Sabas I did run codes and nothing out of the ordinary. Chaffing is a definite possibility with those 20 year old wires & shakers. Really wanted to get the font suspension setup b4 rewiring the efi.

Too complex to test the ECM. If you have a spare just swap it out and see if the problem recurrs.

 

[erwinp]

With the EEC IV system, the Thick Film Ignition (TFI) module mounted on the distributor goes bad enough times that there was a class action.

http://www.autosafety.org/ford-tfi-module-national-class-settlement

Here's a link to troubleshoot the issue: http://www.ehow.com/how-does_5023948_troubleshooting-ford-ignition-module.html

It's pretty easy to replace - 2 screws. You may have to pull the distributor to get to them though.

 

[Terkish]

I had a problem much like your. Turned out to be a loose ground. I would start with checking all the ground connections to the efi system, make sure they are tight.

 

[NYLES]

With the EEC IV system, the Thick Film Ignition (TFI) module mounted on the distributor goes bad enough times that there was a class action.

http://www.autosafety.org/ford-tfi-module-national-class-settlement

Here's a link to troubleshoot the issue: http://www.ehow.com/how-does_5023948_troubleshooting-ford-ignition-module.html

It's pretty easy to replace - 2 screws. You may have to pull the distributor to get to them though.

Great info for a first post .....welcome aboard!!

 

[erwinp]

I used to mess around with 5.0 EFI Mustangs a lot. Last build was a 1989 Notch w/EFI 351 Windsor.

For anyone working with EEC IV, I'd recommend this book: http://www.bentleypublishers.com/ford/repair-information/ford-fuel-injection-elec-eng-88-93.html

 

[marty]

do yourself a favor and check for a intermittent relay. i had one on my brand new rjm harness. the one i had go bad was for the MAF voltage,alternator excite lead, and the o2 sensors. those tyco relays are made in china need i say more. sad thing is i read on the net that the robert bosch company sold the relay part of the company to tyco which is china made.

 

[yakelys69]

TFI module would have been likely candidate but since the issue coinsided with the fuel pump sticking on when turning the key to "on" it pretty much ruled it out for me. Tonight I had a few minutes before the sun went down and while being bitten by mosquitoes found that the short is somewhere between 3 inches before the TPI connector and the TPI.

Ignition on fuel pump continually running, move those 3 wires only and a little relay click the pump is off. Then it will start. While the engine is running move those 3 wires more and the engine dies - fuel pump stays on.

 

[yakelys69]

I can just picture some EFI gurus shaking their heads on my last post. Had nothing to do with the wires to the TFI module. I think the click was from the MAF sensor or IAP, but it was my power junction, the nut was came loose. D'oh!...