de6w6it

Ok, I have 88' runner with the 22re, 5 spd, and it has a bad miss/buck/stutter when accelerating at half throttle. Barely any throttle or WOT and no problems. Also has a rough idle when this problem is occuring. Some days it does it, some it does not. Seems to follow during or days after bad rain or driving when the roads are wet, but I cant seem to figure out/find what would be getting wet causing this problem. Here is what I have done/discovered so far: (some relevant, some not so relevant, but included for completeness)
1) No CEL
2) Swapped in a known good condition ECU.
3) New TPS adjusted correctly
4) Swapped in a known good AFM
5) New plugs
6) New wires
7) New rotor
8) New Cap
9) All new vacuum hoses
10) Blocked of EGR at intake plenum
11) New Alternator
12) Checked for leaks in air intake path
13) Sprayed starter fluid around whole intake system, no leaks
14) Checked all battery grounds
15) Don't think its fuel starvation, because if it is missing completely and bucking and doing its thing, if you push the pedal down to the floor, it accelerates normally.
16) Seafoamed the hell out of it
17) Used dry gas
18) Cleaned intake plenum with intake cleaner
19) O2 sensor is only about a year old
20) cat does not rattle or smell like rotten eggs
21) cleaned throttle body
22) have used fuel system cleaner as a why not try it
23) New PCV valve

If you guys have any suggestions, or things for me to try, I am very open to ideas. Thanks in advance!
DeWitt

isaac338

have you checked your fuel pressure? maybe your pump is going bad, or you have some strange wiring fault that's making it flake out at times. have you changed your fuel filter?

a buddy had an old ford truck that had similar symptoms.. he chased it forever until finally replacing the fuel pump on a suggestion. the truck has run fine ever since

de6w6it

I will be honest, that is a great suggestion, and have thought about it, but my fuel lines are so rusted, and so is the filter, and the fittings at the sender unit on top of the tank. So...I have decided not to touch any of it right now, and wait for warmer weather, and replace it front to back, drop the tank, and go from the sender, to the filter to the rail and replace all at once. I fear that if I touch any one part of it, that it is going to disrupt the delicate balance of how the rust is holding it together. I will probably rewire the sender and such while I am down there also. Thanks for the suggestion, I definitely agree this may be the problem.

isaac338

if you have a helper you can get under the rig (parking brake on!!) and listen for the fuel pump. it should (afaik) be pumping continuously - get the helper to rev the engine to the sputtering point and see if you can hear the pump cutting out.

or get ahold of a fuel rail pressure gauge and use the service port on the fuel rail to see if you're getting dips in your pressure. that could also be caused by the fuel pressure regulator, i'd assume. good luck!

de6w6it

ok, thanks for the info, I will try that on saturday with my brother!