So I have a 1998 F150 4x4 w/ a 4.6l V8 and a 5speed manual tranny. Its got 173000 miles on the truck and only 15000 on the new engine. I have replaced everything under the hood. You name it, Ive done it, but the problems never seem to end with the truck. about 4 months ago i was sitting at a redlight. my buddy pulled up next to me in his truck. her reeved it up...so i did the same...but when i did it, the was a loud ping noise and the truck shut off. the ping was a detonation after the engine had shut off. the truck would turn over but it wouldnt fire... i towed it to a shop and they told me it was a crank sensor so they replaced it...still nothing....they told me it was my pcm...so i replaced it....still nothing i thought the cam sensor might be bad...i replaced it. still nothing. i replaced both coil packs...still no spark. i have the correct power coming to the coil packs...but nothing coming out of them...everyone has told me its my pcm still....but i just paid almost $300 for a brand new PCM that didnt solve the problem...anyone have any thoughts?

 

Could be the PCM. Hate to tell you that. Some friends of mine replaced the PCM's in both their 7.3 Excursion and 7.3 1 ton. Less than 5000 miles later they were both shot. PCM's for these vehicles are not new, just remanned and reflashed because it's old technology that isn't produced anymore. It's considered "like new" but I have several experiences where "like new" is not new and just as bad as used. Frankly when it comes to modern electronics in vehicles, they really aren't worth replacing unless they are under warranty. Look at it this way, most people get a new computer every 4-6 years and junk the old one because it's old technology or it crashed for some reason. When you start having issues with electronically controlled engines its usually just easier to go mechanically controlled. That's my plan with my 4.2. I've put almost more money into the engine alone than what I paid for the truck with 67K miles on it by the time it had 104K miles on when I had only had it for 2.5 years. It's getting a mechanical Cummins B3.9 4BT next summer because I'm tired of dealing with the electronics.

 

Thanks man. I just hate to do that cuz i bought the engine brand new. not remaned...brand new. lol. it only has 15000 miles on it. everything under the hood has less than 15000 miles on it. I thought about pullin my engine and tranny and tcase and stuffing it into a 99 expedition and makin a 1 of a kind custom expedition with a 5speed manual trans...but i would really love to get my truck running. i was gonna take the computer to ford and have them reflash it to see if that does it or not...i just hate to get rid of the truck...maybe ill part it out or something. or take all the **** i done to it out and just scrap the truck.

 

Drop a Cummins 4BT in there. Should bolt right up to the transmission. You'll drop nearly 100 hp but gain almost 80 lb-ft of torque. Should get about 29 mpg too. Guys have done that to expeditions and then put the 5 speed right behind it. Just have to research it a bit.

 

Not to mention I've had a slight piston piston slap on one of the cylinders since 98K miles.

 

My truck was doing the same thing only I have an EDGE PERFORMANCE power programmer and I used it to flash the PCM back to stock even though it was already at stock and it fixed everything... My other advice is NEVER use reman brand parts because they are in reliable and they suck.

 

ehh...i think im gonna just pull everything appart and put a 302 in it...maybe. or ill just get the engine outta it and scrap the truck.

 

There are some places out there that will give good money for a mechanically sound 4.2.

 

Ive got a 4.6l with only 15000 miles on it. i hate to pull it again...but it looks like thats what im gonna have to do...

 

Yea my bad. Should still be able to get good money for the motor