so i fixxed the rear ujoint....now on to the next problem!!! random missing????

[Oldskool153]

so i picked my car up from the mechanic (after having my rear halfshaft u joints changed yesterday) today i ptu roughly 100 or so miles..now i bought the car in september and everynow and again its always had a random miss that will show itself only under heavy acceleration....its hard to explain its either a miss or the engine is starving for fuel..but for example lets say im doin 30mph and i nail it, most of the time it picks up and takes off with no probs but maybe one in every 20 times it will bog for a second then take off. the problem mainly shows itself when im either low on gas or just after i get gas for the most part. more recently it seems to be doing it more frequently.. today i was doin 50 and nailed her and the engine actually cut off for a second then as soon as i let off the gas came back on. this today happened right after i got gas. when the problem showed up in the past i would put a can of sea foam in and things would straighten up.. after the car did that today i drove it to wallmart and put a can in, then hit the highway (where she was bogging every few seconds under heavy onramp acceration) i drove for about 30 miles at speeds above 80 then turned around and came home..she seems to be fine right now(knock on wood). my question is what could this be? and why does it usually occur after putting in gas and why does the sea foam usually help? should i be looking at fuel pumps, opti sparks, water in the tank, dirt in the tank or what???? any help would be great, i had my mechanic try to diagnose the prob months ago but we culdnt get the car to reproduce the prob (typical) 99% of the time the car runs great. its a 92 with 87k it had 82k when i bought her almost a year ago so it does sit alot.

 

[boomdriver]

so i picked my car up from the mechanic (after having my rear halfshaft u joints changed yesterday) today i ptu roughly 100 or so miles..now i bought the car in september and everynow and again its always had a random miss that will show itself only under heavy acceleration....its hard to explain its either a miss or the engine is starving for fuel..but for example lets say im doin 30mph and i nail it, most of the time it picks up and takes off with no probs but maybe one in every 20 times it will bog for a second then take off. the problem mainly shows itself when im either low on gas or just after i get gas for the most part. more recently it seems to be doing it more frequently.. today i was doin 50 and nailed her and the engine actually cut off for a second then as soon as i let off the gas came back on. this today happened right after i got gas. when the problem showed up in the past i would put a can of sea foam in and things would straighten up.. after the car did that today i drove it to wallmart and put a can in, then hit the highway (where she was bogging every few seconds under heavy onramp acceration) i drove for about 30 miles at speeds above 80 then turned around and came home..she seems to be fine right now(knock on wood). my question is what could this be? and why does it usually occur after putting in gas and why does the sea foam usually help? should i be looking at fuel pumps, opti sparks, water in the tank, dirt in the tank or what???? any help would be great, i had my mechanic try to diagnose the prob months ago but we culdnt get the car to reproduce the prob (typical) 99% of the time the car runs great. its a 92 with 87k it had 82k when i bought her almost a year ago so it does sit alot.

It sounds typical...bad fuel pump with intank strainer thats full of rust. Inline fuel filter that might be full of trash.

Use a fuel pressure gauge to see for sure.
These car also have a serious fuel system flaw, when they get under 1/2 tank they loose fuel in cornering, ANY curve or stressful cornering will make the motor starve for fuel.
To solve this, build a small cup that thepump & tubes all live in and set the whole mess in tnhe tank,. This keeps the little pump full of fuel since its all in a plastic can inside the tank,. hey, it works ! The stock windage tray glued to the tank bottom is very inadequate.

 

[Oldskool153]

Should I be looking at the pump or pressure regulator? Or filter? I may just change all 3

 

[boomdriver]

Should I be looking at the pump or pressure regulator? Or filter? I may just change all 3

The regulator is most likely ok. A pressure gauge will tell the story.
Its usually the filter but with these things, if trash got as far as the filter it passed thru the pump and the strainer. rule of thumb is that if you go inside the tank....go ahead and replace the pump & strainer.
The inline filter is first, then see how it does. If the fuel pressure is still an issue then proceed to the pump & strainer. The more a pump runs dry the faster it fails. These tanks are not very deep but they are wide, so cornering tends to throw all the fuel to the side when its low and that lets the pump suck air for a second and run dry.

When you do the filter, look at all the threads here for some "how to" ideas. It can be VERY messy and with gasoline, very dangerous. I like to pull the fuel pump fuse or breaker and run the engine until it dies from lack of fuel. That uses as much as possible so the lines are not quite as full. Gravity still makes a mess.

 

[Oldskool153]

gonna do a pressure test this weekend. me and my mechanic have been chasing this problem since i bought the car, the prob is that its so intermintant that it doesnt replicate the problem long enough to get a good diagnosis. i failed to mention to my vet mechanic (best vet guy i know and has worked on vets for over 20 years) how everynow and then when i hit the gas at a roll not only will it sometimes bog for a second it will stall for a second then as soon as i let off it will keep running. however when it stall for that second all my gauges turn off as if i had turned the key off, he seems to think the problem may be electical not fuel. he said it its shorting for a second or 2 that will cut my fuel pump off.. idk what the prob is it could be so many things its confusing because i dont want to just throw parts at the problem i want to find out whats wrong and fix it. so i dont waste more time and money then i have to. i told my mechanic tonight that i want him to drive the car for a week, because the probelm is either very intermintant or i dont drive the car enough to see the problem that often. it sits during the week, so i want him to drive it for an entire week..im pulling my hair out and loosing sleep over this issue lol why cant my car just run 100% all the time? lol its always something ha