My '86 GT is sputtering and bogging down like crazy under acceleration, sometimes popping and backfiring a little too... However it only seems to do it when the car is warmed up, not when its cold. It gets so bad after a while that it doesn't want to move at all and will barely idle and if you hit the gas it will just backfire and not rev up. It was MAF converted but I don't think that's the problem since I don't think the engine being hot or cold would matter with that. Plugs and wires seem fine, already replaced the fuel filter. It has a Walboro 190 fuel pump in it and I've never really heard of those shitting out, but who knows... What do you guys think the problem is? Any feedback is appreciated, thanks. I am thinking it has to be either the pump or EGR???
Yeah I think its the pump too. So tell me this...I bought a brand new BBK 155 pump for it and the plugs on my fuel harness don't match up to the outlets on the new pump...Wtf? Are the outlets different on a 155 pump VS. a 190???
Before changing the pump. Run the codes. You'll get lean codes if it is the pump. Could also be a dead or dying injector. A cylinder balance test can pick that up (part of code reading process)
Well worth it to take 15 to do this before throwing money at the problem and hope you are right
I know this is an old thread but I just wanted to update everyone... So far I've done a new fuel pump, fuel filter, cap and rotor, cleaned MAF sensor, oil change, full exhaust without cats... Problem still persists. I'm sending the car to Enhanced Street Performance in Sterling, MA to have them try to diagnose it and do some other mods to the car. Only other things I could think of would be bad O2 sensors or maybe fuel pressure regulator but I don't really wanna throw more money at it until someone can possibly pin point what it is.
-- Edited by 52Floor on Thursday 12th of May 2011 03:30:31 AM
Pickup in disty? Or tfi? Or intake manifold leak or valve covers could b a vaccum lesk I just dealth with all that ended up being intake leak and vaccum hoses
Could be map sensor . I had one that only acted up when warm . had stock cam , but idled like it was a pro stock . It would back fire and run like shit .... unles you went to W.O.T. , then it would rev . The other thing you could check is the computer ground . Make sure it has a good clean metal contact , it could also be loose . Seen a couple of stangs exibit the symptoms you have because of the ground .
Pick yourself up a good repair manual it will help !! plus you will learn somthing about your car and not be at the mercy of big repair bills .
What computer are you running? If you changed from mass air back to speed density, did you change the computer. A mass air car needs a A9L. Advance sells a replacement A3M which is the A9L replacement for 80 bucks... Try swapping in someones computer and give it a try?
Thanks for the advice guys... Jay my car is mass air I didn't go back to speed density so I don't think thats the problem. I'll post up the problem once we figure it out, I know somebody on here is probly curious.
I have a thread in this section about this same problem my car was having. I changed the tfi module distributor cap and rotor new wires new plugs fuel filter fuel pump fp regulator. Cleaned mass air flow. Changed mass air flow. Cleand iac. Changed tps. Oil change. Cleaned air filter. After all this it was a vacuum leak. Check that first. Its a very cheap fix if it is and you won't be throwing money at it like I did. Pm me if you want more details on what was wrong with mine. It had all the same symptoms of your car though
DMURB thanks for the advice and I'm gonna send you a PM... However I did end up sending my car out to a Ford tech, a family friend that runs his own shop and is real good with these cars. The computer wouldn't throw any codes so he did a trial and error on it. This guy tried changing every part imaginable including a different computer, different mass airflow sensor, etc. Apparently he finally ruled it out to be a bad distributor / tfi unit which we are in the process of replacing now. I really hope he was right... This guy really knows his shit so I would assume he would've found a vacuum leak if thats what it was, given all the equipment and experience he has but who knows. Lets see if a new distributor takes this mess away.
yesterday is history tomorrow is a mystery
