hello,maybe somebody can help me. motor runs great until it heats up,then at idle when i give it gas it will bogg down and stall if I continue to give it gas. once I get it out of 1st gear no problems.had everything checked at local garage,distributor,coil,ignition module, throttle control valve ect.mechanic advanced timing 5 degrees doesn't do it as much but still does it. he gave up doesnt know what else to check. anybody have a idea.local dealers really don't won't to mess with it thanks bob

 

its a 1994 so i imagine its fuel injected right? Have you had any check engine light codes? If so that would be tracked data. Sounds like it could easily be a fuel system problem. How are your spark plugs? thanks.

 

thank-you for replying, had dianostics test done everything is good, it has new plugs wires cap,rotor,mechanic changed distributor,ignition module throttle control valve,one or two other sensors forgot what they were,but he says everything electrical is checking out ok.had fuel gauge on rail checking pressure. everything ok.i have same exact truck change computers seeing if that is the problem to no avail.the only thing he did is advance timing 5 degrees problem is not as bad but still exist . thanks

 

Well if all those ignition parts are good, and the fuel pressure was where it should be i would imagine the problem may lie somewhere else. Something most people would not consider checking would be the timing chain and gears. If you advanced the timing and that seemed to help, the problem could lie with a bad timing chain and gear set. I once had a 302 v8 ford F150 pickup and the chain got stretched from wear and tear. If you turned over the engine by hand crank by crank you could measure the difference. It was anywhere from5/8th to 3/4 of an inch at max. Thats why the engine would run good and run good then start running bad, and return back to bad. Other wise there are always vacuum lines and such simple things like that, but i don't think this would be a vacuum line related problem. I would think about bad valves or fuel injectors. The engine may be either flooding itself or running too lean from idle and after that it corrects itself. Hard to believe the problem only exist when your starting to move from a dead stop... Thats a tricky one. I think your problem could be in the fuel delivery though. As the O2 sensors may be malfuntioning, it floods the engines at lower Rpm maybe and clears up at higher Rpms. Something like that?? But im not sure. Fuel injection systems are great and work reliably for years with only minor maintenance. Carburation usually has problems like this. This is a tricky problem to solve

 

How many miles are on the motor?

try timing it by ear without the marks on the ballancer. Maybe the ballancer is moving on the rubber? Pull the #1 plug out and check to see if tdc is tdc..

That is interesting that advancing the timing helped. Must be a clue. Does the distributor still have vacuum advance on those? Could have a bad spot on an insulator? I bet by then it was all electric though.

Id check vacuum. Id check the cam to crank timing. Does any one have the valve lift numbers for ford gas engines? Is that even something that is done?

After you've checked all the mechanical options go out to a junk yard find one of those engines, take all the sensors off the engine and the exhaust and start replacing them one by one on your truck..

One thing on the throttle body ford engines of the 90's. I had a little tempo car for a while back when, and that little guy had a hell of time running because the chip on the distributor burnt up.

My car flooded so bad if you held a lighter to the exhaust it would shoot flames... So if yours does that. Good chance the distributor chip went out.