Matlock

Hello, i am new to this forum. I am a novice mechanic, but now how to do basic maintenance and repairs. I have a 2003 F150 Supercrew Lariat with 4.6 2 wheel drive 138K miles. The day befor the problem started i drove my truck about 150 miles no problem. The truck set for about 20 hours over night and most of the day. When i drove the truck the next afternoon i notice a jerking when i accelerated. It got worse by the minute while driving it for about 10 minutes. I thought i might have bad gas so i fueled the tank, but still bad. finaly the check engine light came on on my way back home. I took it to autozone and they said it was a p0302 missfire in cylinder 2. I changed the front 4 spark plugs and replaced the coil and fuel injector on number 2. Still ran very bad, so i put some fuel injector cleaner, drove 30 minutes, but still ran the same. Then i replaced the fuel filter. The fuel filter was awful and completely stoped up. the gas was dirty and had traces of oil in it. The cat converters were check and still good. A compression check showed cylinder 2 was 25% less then the other cylinders. The mechanic said dirt must have goten past the fuel filter and damaged the rings on cylinder 2. He told me it was ok to drive it now. said i would just have to live with the jerking and lack of power. after that i drove it around some more hoping the fuel injector cleaner would improve things. after driving for 15 minutes i was turning a shap corner and my engine just died while going 25 mph. I manged to pull to the side of the road. the truck started right back up. After that the truck ran quite a bit better, but still bad. I went from having about 40% power to about 75% power. on my way back home it died on me again at two stops. The stalls seemed very random and idle was fine most of the time. My other mechanic friend doesnt believe dirt can get past a fuel filter enough to damage the cylinder. He believes its an electrical problem. this morning i noticed when i locked my truck usualy if i lock it using my remote the horn honks, but it wasnt dsoing it this morning and my panic alarm wasnt working either, but it was locking and unlocking the doors. Any help or oppinions are appriciated. sorry for the long post.

AjayQuickyBrown

maybe a bad ground somewhere? did u take the sparkplugs out and look for oil? what about resetting the ecu?

Matlock

I check and replaced the front four plugs. the driver side plug 1 & 2 had tracees of oil, but not bad at all. Is there any specific ground i should check? How would i go about reseting the ECU? Thanks for your reply!

2wd supercrew mudder

go to a dealer to reset your computer i belive

Matlock

Thank, but let me rephrase that question whats the cheapest way to rest it? trying to avoid the devil, i mean dealer.

2wd supercrew mudder

cant help ya there man not sure but i know must places charge just a 100 bucks to track the problem

jhelrey

Advance will allow you to use their code reader and you can erase them yourself

twin

im curious ill def. be checkin in on this post to check and see what you come to find out....good luck and hope all goes well

Matlock

Update on my truck. I took the advice of my dad and my michanic. They said to drive the truck around to burn up all that gas with the fuel injection. They said the low pressure in cyl 2 wouldn't keep me from driving it. Well i drove the truck yesterday 5 min to work and 5 min to lunch and 5 min back to work. 5 minutes back home everything was ok. Truck was still running about 75% power and jerking in drive and reverse, but wasn't stalling. Then i drove it to town for about 20 min everything was the same, then at a red light it dies on me. complete shuts down without a jerk or noise just lost trurned off. I started it back with a slight hesitation. Then drove it another 5 minutes to a friends house. I left it runing in park for about 20 minutes. Then backing out of his driveway the engine just turned off again. started after hesitation and drove it about 6 blocks down the road. It didnt shut off at every stop, but atleast half of them. Once i was turning a sharp corner and the power steering was gone which almost made me hit someone. I parked it at a store and shoped for 30 minutes. Then started my drive back home through town. the truck got worse by the second. now it dies at every stop and has about 40% power again. The check engine light came back and hasnt gone away yet. waiting on a friend to tow it to a shop, since im afraid to drive it now. guess ill have a diagnostics test done now. Thanks for your interest in my post, if you have any advice im listening. Sounding more and more like the ECU.

Matlock

I was researching the ECU and it does sound like my problem. Not much info online about how to change or reset one though. From what i read it sounds like the ECU is under the dash on the passanger side attached to the firewall. Does anyone know how to change one or reset it. Is it as simple as pulling the old one out and puting a new one in? or do i have to have the dealership change seting to the new ECU? Anyone out there an expert on this?