Hey guys, so Ive come pretty familiar with ol reliable over the last few years but Im stuck with whats going on. Please help Its my daily and need her on the road asap. Its a 92 4.0 automatic, cold air intake, 33’s w 6 inches of overall lift. (4 suspension, 2 body) So on occasion, here recenty, she takes a little cranking to fire up. Once Its good and warm, and (possibly) when I press the brakes hard it stumbles down and goes into a fit of stumbling hard, misfiring and if I accelerate any more than verry lightly past maybe 1100 rpm, it starts to backfire and pop and can only get up to 15mph. After getting home I threw it in park, then reverse and it cut off. Tonight I replaced the air intake temp sensor, coolant temp sensor and a brand new fuel pump. I disconnected the battery, as well as the crankshaft sensor as a suspected culprit but have replaced it around 7 months back. Could this be my issue again? So I put the tank back and reconnected everything, cranked right up no problems and ran noticeably better. Until I really gassed it while headed home after getting warm and it started acting up again. Last year my rear driveshaft fell out and smacked my cat converter and broke the ext. housing but after replacing the slip yoke, and trans case ext. housing its done fine. It sounds like a sensor issue to me but does that have something to do w the issues Im currently having? Could it still be a fuel issue? I have not tested pressure other than visibly before the fuel pump replacement and was pretty weak. Ive been using mid grade gas. In the last year Ive replaced:
All spark plugs/wires/rotor cap/ignition coil
Tps
Upstream o2
Brake booster
Rear brake lines
Rear u joints (several times)
Crankshaft pos sensor
All front steering components excluding power steering box
Trans mount
Slip yoke
Trans case ext. housing
Fuel filter (5 months)
Fuel pump
2 bad injectors (maybe a remaining one is leaky?)
All fluids, but does need an oil change.
Im pretty sure theres more, if any come to mind Ill update. I was having a bad misfire about 2 months ago and once the injectors were replaced it was back to normal. Before I disconnected the battery, crank pos, and installed the air intake temp, coolant temp, and fuel pump it would run very rough at idle. like it wasnt building vacuum pressure like it does normally, to the point it would rock the whole jeep side to side. Once I reconnected the battery and crank pos sensor it ran smooth at idle and in drive and thought I had got it, until it got to running temp. Now Im back in the same boat. Also it was running rich before the new fuel pump. Heavy exhaust smell but is gone now. Theres a spot where my cherrybomb isnt properly sealed to the cat, but runs fine until it gets to temp. I had to cut out the pipe passed the cat after my driveshaft banged a bad dent in it. If you can help me please get back to me!!
All spark plugs/wires/rotor cap/ignition coil
Tps
Upstream o2
Brake booster
Rear brake lines
Rear u joints (several times)
Crankshaft pos sensor
All front steering components excluding power steering box
Trans mount
Slip yoke
Trans case ext. housing
Fuel filter (5 months)
Fuel pump
2 bad injectors (maybe a remaining one is leaky?)
All fluids, but does need an oil change.
Im pretty sure theres more, if any come to mind Ill update. I was having a bad misfire about 2 months ago and once the injectors were replaced it was back to normal. Before I disconnected the battery, crank pos, and installed the air intake temp, coolant temp, and fuel pump it would run very rough at idle. like it wasnt building vacuum pressure like it does normally, to the point it would rock the whole jeep side to side. Once I reconnected the battery and crank pos sensor it ran smooth at idle and in drive and thought I had got it, until it got to running temp. Now Im back in the same boat. Also it was running rich before the new fuel pump. Heavy exhaust smell but is gone now. Theres a spot where my cherrybomb isnt properly sealed to the cat, but runs fine until it gets to temp. I had to cut out the pipe passed the cat after my driveshaft banged a bad dent in it. If you can help me please get back to me!!
