I have a 1992 F150 PU with a 4.9 straight 6 engine, automatic transmission with overdrive. The computer is possibly the cause of my problems - this truck has been at the mechanic's yard for 3 months. Every morning the mechanic/owner would drive it out of the shop into the yard and let it run. Sometimes it would run for ten minutes and stop, sometimes it would run half a day before it stopped. When it stopped he would turn the key off and then on, the fuel pumps would run continually and the engine would not start. After a while with the ingnition off for some time, when the ingnition was switched on the fuel pumps would run, then after a couple of minutes the engine would start. When the fuel pumps were running continually both wires running to the injecter had positive readings but no ground. Other than the computer does anyone have any ideas as to what could be my problem. The local dealers parts office can not even tell me what is the number of the correct computer or if there have been any recalls on this model. The computer has a date of 1993 and the truck is a 1992. I bought it used and the previous owner is no longer around. I am having trouble also finding a used computer to try. I just found this site and this is my first post. Thank you.

 

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I had the exact same problem with my 92' F-150 300cid six cylinder just last month. I tried all of the regular stuff, pulled codes, nothing, complete tuneup, nothing, finally I was convinced that it must be the EEC/PCM so I pulled it and found that water had entered behind the firewall gasket and there was corrosion on the computer housing, on the mounting bracket bottom as well as in the connector, I cleaned all up and reinstalled with a good bead of silicone sealer around the fire wall gasket and...Poofff! truck ran like new!!! I then began checking all of engine compartment electrical connectors cleaning them with "CRC" brand electrical contact cleaner as this brand and type won't damage plastic, them I sprayed them liberally with "CRC" electrical grade silicone die-electric lube protectorant..all available at Lowe's. I found alot of corrosion here and there. Living right on the Gulf coast with 160'000 miles I'm not surprised. If you look at the drip trough running along the drivers side firewall engine compartment going down it runs right under and near the computer mount with the 80 odd pin electrical connector so water is draining very close to it when raining or washing!

Also pulling the computer will give you a chance to get all of the numbers off of it for future reference. It's not a big deal to remove as it comes off inside the engine compartment.

Lee

 

Thanks for the advice there is corrosion so this may be my problem. I will let you know how it works out.

 

Man, this post mays well have been mine! You are describing my problem almost exactly. Thanks for the reply aspaceintime, this is probably whats going on with my truck. I saw that connector, and it looked like it wasnt seated completely up against the firewall but havent taken it off to inspect it yet. I bet I find a problem there. Thanks again!

 

Ditto on problem, had the same thing happen to me. I replaced the computer and sealed around the socket and firewall and have had no problem since. I priced the part at local automotive stores and shopped around for the correct one as ford has upgraded it since the initial installation in 92. If you need part number just drop a line, however I have a manual tranny.

 

Well I pulled the EEC connector off only to find it clean. Also pulled the computer out and removed the covers, but clean to. I suppose the computer could still have an intemiten (never could spell that word!) problem. I'm only $110.00 dollars away from finding out! I think I have access to a used computer to see if it will fix it without having to spend the money (which is not refundable in most places). Will post results soon.

 

Dear Friend, I spent last weekend doing exactly what you suggested. You are spot on. I have a working truck and I had minimal expense. Thank you for the quick reply.
Frank Bihm

 

After taking all grounds loose and putting sand paper to the surfaces, the problem has not come back. Although the grounds looked ok and didnt seem to need to be cleaned, it sure has made a difference doing so. I was in no big hurry to get it back on the road and start paying 2 dollars a gallon for gas! Some of those posts about never having to many good grounds is true! LOL Thanks