1991 ford f150 5.0L wont start unless fuel pump primes, most of the time fuel pump just stays running with key in on position. If i turn key on and off a few times the fuel pumps prime and shut off then the truck will start. It will run smooth for a few minutes then the check engine light comes on and has no power and starts idling rough, almost feels like the transmission is slipping but it's not because if check engine light goes off the transmission has plenty of power. When I turn the key on and off until the fuel pumps prime when i first start it the check engine light is off it comes back on after a few minutes of idling. I have changed the fuel pump relay, ecc relay, fuel pressure regulator pvc valve. Any ideas any help would be much appreciated?

 

does it have 1 or 2 tanks? which pump did you change?

 

I has duel tanks I didn't change either pump. I ran a code scanner it came back Cylinder #1 spark or fuel injection problem, you think a bad injector could cause the fuel pump to continuously run?

 

no, when you turn the key to KOEO the pcm commands the fuel pump to run for 1-2 sec. then its suppose to shut it off until you crank it over. that issue generally points to a pcm failure or a problem in the wiring harness or the relay sticking.

 

When you say PCM im assuming your talking about the trucks computer I get the confused ECC, PCM, EEC etc. Sorry I have limited knowledge regarding electrical problems. I was told my computer may be bad by a friend would it be possible for you to link the part you are describing. Thank you.

 

Classic symptom of a burned EEC/PCM/computer. Pull the driver's kick panel, pull the EEC clamp, and smell the EEC. If it stinks, back out the bolt in the center of the connector (in the engine bay), pull the EEC out, and take the covers off to look for signs of heat. Post a few pics.

A reman EEC is ~$100 at most parts stores, but stay OUT of the zone. Get one with the same calibration code (3 big digits on a white sticker) as your original.

Automotive Terms & Abbreviations

 

Great info guys thank you I will look at the EEC and post some pics.

 

It definitely smelled burnt



http://picasaweb.google.com/sedwardz...33333529916146

http://picasaweb.google.com/lh/photo...eat=directlink

 

Rockauto.com:

A-1 CARDONE Part # 785092 Reman. Does Not Include PROM - Return and Rebuild Service Only - By ordering this service you are agreeing to send your original part to the manufacturer to be rebuilt. Rebuild time is approximately 3-5 business days. You will be contacted with directions once the order is placed. For more information please contact Customer Service.
Trans. code E4OD; Automatic trans.; Calif. Emissions; w/I.D. #F1TF-XB

$184.79
$70.00 core charge
$254.79

 

I am trying to find the correct computer online. The one I pulled from truck was F1TF-12A650-XB which according oreillyauto.com. (scroll down to F1TF-XB Part #78-5092) http://www.oreillyauto.com/site/c/se...150&vi=1122006 says it's for a E4OD Transmission my truck has a automatic transmission but has a overdrive on/off button. I am not the original owner I'm wondering if someone replaced the computer because the drivers side kick panel where it is located had no bolts or screws holding it in place, I just pulled the kick panel out. I have had the truck for 5 years and it ran great until recently. Can anyone help me find the correct computer please?

Here are the specs

VIN A45594
DECODED 1991 Ford F150
Country UNITED STATES
Make Ford
Vehicle Type Pickup Truck
GVWR Class Class E: 6,001-7,000 lb
Model F150
Engine Type V8, 5.0L
Check Digit 4
Model Year 1991
Assy. Plant Kansas City: Claycomo, MO
Production Seq. # A45594
Brake System Hydraulic
Body Type 2 Door Cab; Super Cab
Trim Level Base
Drive Line Type 4WD
Vehicle Class Full-size Pickup
Fuel Type Gasoline
Manufacturer Ford Motor Company
Engine Code N

 

I really wanted to see the INside! The calibration code is what matters, and yours is E1A1.Right. The "E" in E4OD means "electronic", and only electronic automatics have a control switch. Read this caption:

Right. Just a pushpin near the forward corner, 2 pushpins near the door jamb, and it tucks under the end of the door threshhold.That's the way they normally do: they run well until they start running badly, or not running.

 

Thank you GLC I didn't see your posted when I posted mine great info do you still think that is the correct computer without having a E4OD; Automatic trans

 

Thank you Steve you answered my question I will order one tomorrow. I'll let you guys know if it fixes the problem, Thanks for all your info great site

 

Note that this is a send in to be rebuilt price, not a direct replacement. The "XB" is for a E4OD with California emissions. I think we have established you have a E4OD, does the compliance sticker under the hood say anything about California emissions?

 

Popz, call any NAPA in yer area. When the computer died in my 91 Bronco all I had to give them was the VIN and they got me the correct one ready to install. As I remember, it cost about $200.00.