I have a 91 F150, 302 V8. About 3 weeks ago, my truck started acting up, would turn over, but not fire. Let me back up, it did this about 4-5 months ago. It just out of the blue started not wanting to start for me. It got to the point that I had to mash the pedal down just to get it started. Back then, it was throwing a HEGO code, so I disconnected the O2 sensor, and it stopped acting up(started sucking gas) but nonetheless started for me each and every time.

Now,as of 3-4 weeks ago, its doing the same thing. It started doing it one day out of the blue. The past few days before that, it sounded like the idel was loping, but only when it was sitting at idle for more then 5 minutes (in the drive picking the kid up form babysitter) But that was all it was doing. Then one day, it wouldnt fire, would only turn over. Then 3 days later, it started right up, ran good for about 2 weeks, then BAM, back to the same crap. I noticed that when it was happening before, it was right around a climate change (hot to cold out = would act up, warm up and it wuld start), I took the IAC valve off, cleaned it real good with throttle body cleaner, stuck it back on there, and that didnt help. Its not pulling any codes other then 1-1 SYSTEM PASS (granted I am using the paperclip method, but thats always been pretty reliable).

Last weekend, I was able to get it started, by removing the two breather hoses from the throttle. It started, ran fine, idled good... until I took it up to auto zone to have them use their code reader (which by the way they refused since it was older then a 96). While I was driving, I would get it to about 20 mph, and it would start cutting out, so Id have to gradually increase my speed ot get it to 35-40 mph.. I got it back home, and revved the engine, and it started backfiring on me. Now the thing will not start, its almost like it's flooded.

What could it be? Timing? I do not want to take this to the shop. I know a little about cars (enough to be dangerous) but I am determined to get this fixed at my house.

Any help would be GREATLY appreciated. Thank you

 

so.. lemme see if I get this. You are running with the O2 disconnected, and vacuum lines off....

k...first, new O2, reconnect your vacuum system, replace the IAC, they don't clean up worth a damn....THEN replace your plugs, because you have probably now fouled them so bad they are useless... If it runs at that point, clear your codes and run it....see what it throws at you.

 

start by checking spark plugs for that matter just change them 2nd ensure that the fuel presser regulator is not leaking pull vacum line off and make sure it not leaking fuel 3rd have your tfi module checked out napa can do it around here 4th check distributer for wear in the bushing its either a matter of not enough fuel of hoaky spark distributor can get loose and change the clearance between hall effect sensor and give it wrong spark signal sensor is located where they used to put points