Hey Guys-
I have an issue with my 94 XJ that is driving me crazy.
I read many posts on this topic before asking these questions.
Here's what's up:
I bought this 94 4.0 Auto XJ last year with 90K on it, but it needed some love here in the NE rust belt (ha. 90K and newly replaced floors). When I got it, it did not ping or hesitate. Over time it started to ping going up hills- the pinging would go away if I either put Seafoam in the tank or ran 89+ Gas.
OK, so I figured I'd get around to misting through a vac hose with either water or Seafoam assuming it was carbon. It might be relevant that it was running hot due to a leak between the block and water pump (but never overheated)- maybe that contributed to carbon? Anyway-
I replaced the water pump, hoses, the rattling PS pump, idler pulley, everything happy, not pinging at this point.
Pinging over time starts getting worse, but I'm not pushing it and doing other repairs to get to work and pass PA inspection- totally new exhaust end to end, O2 sensor, brakes, shocks, steel brake lines, fuel filter. Still not hesitating, and shifting right.
At first I used 3/8 rubber line for the filter and just clamped it down- so after reading when the hesitation started, I thought I might be sucking air so I replaced the rubber fuel line with 5/16 and correct clamps. Still hesitated.
The symptoms are for one as if on a flat road going 55 you are rapidly switching off the ignition and back on again- it can do it once, or repeatedly, but changing the throttle seems to make it go away for a little (getting on it or backing out of it)...and then it starts again in the same 45 min trip to work.
At the same time, the Auto trans started to shift as if I put a shift kit in it.
1st winds up more than it used to, and it (too firmly) shifts into 2nd. The shifting and hesitation started simultaneously, so it seems like they might be related.
OK- NEW:
Cap, Rotor, Wires, Air Filter, fuel pressure regulator, 90 deg regulator rubber vac end, inspected all other vac lines and rubber ends (but not replaced), new "higher end" Standard Ignition TPS. (this after trying an Advance Auto TPS which sucked bad)
Still has hesitation and Firm shifting.
I did not replace the plugs- I'm still planning on misting to remove carbon and don't wanna foul new plugs, plus it seems unlikely to me that plugs are the root cause here.
I did not touch:
The Idle "plunger" on the throttle body
The MAP sensor
Air Temp sensor
Crankshaft Sensor
Fuel Pump
It starts and idles fine.
The steel fuel return line is ugly as is the large vapor hose going to the under hood canister.
From what I've read in the forums, it seems I could chase this until I've replaced everything. Bleeding on a 20+ year old XJ every spare moment is starting to lose it's shine. :gee:
Any helpful suggestions?
Thanks
I have an issue with my 94 XJ that is driving me crazy.
I read many posts on this topic before asking these questions.
Here's what's up:
I bought this 94 4.0 Auto XJ last year with 90K on it, but it needed some love here in the NE rust belt (ha. 90K and newly replaced floors). When I got it, it did not ping or hesitate. Over time it started to ping going up hills- the pinging would go away if I either put Seafoam in the tank or ran 89+ Gas.
OK, so I figured I'd get around to misting through a vac hose with either water or Seafoam assuming it was carbon. It might be relevant that it was running hot due to a leak between the block and water pump (but never overheated)- maybe that contributed to carbon? Anyway-
I replaced the water pump, hoses, the rattling PS pump, idler pulley, everything happy, not pinging at this point.
Pinging over time starts getting worse, but I'm not pushing it and doing other repairs to get to work and pass PA inspection- totally new exhaust end to end, O2 sensor, brakes, shocks, steel brake lines, fuel filter. Still not hesitating, and shifting right.
At first I used 3/8 rubber line for the filter and just clamped it down- so after reading when the hesitation started, I thought I might be sucking air so I replaced the rubber fuel line with 5/16 and correct clamps. Still hesitated.
The symptoms are for one as if on a flat road going 55 you are rapidly switching off the ignition and back on again- it can do it once, or repeatedly, but changing the throttle seems to make it go away for a little (getting on it or backing out of it)...and then it starts again in the same 45 min trip to work.
At the same time, the Auto trans started to shift as if I put a shift kit in it.
1st winds up more than it used to, and it (too firmly) shifts into 2nd. The shifting and hesitation started simultaneously, so it seems like they might be related.
OK- NEW:
Cap, Rotor, Wires, Air Filter, fuel pressure regulator, 90 deg regulator rubber vac end, inspected all other vac lines and rubber ends (but not replaced), new "higher end" Standard Ignition TPS. (this after trying an Advance Auto TPS which sucked bad)
Still has hesitation and Firm shifting.
I did not replace the plugs- I'm still planning on misting to remove carbon and don't wanna foul new plugs, plus it seems unlikely to me that plugs are the root cause here.
I did not touch:
The Idle "plunger" on the throttle body
The MAP sensor
Air Temp sensor
Crankshaft Sensor
Fuel Pump
It starts and idles fine.
The steel fuel return line is ugly as is the large vapor hose going to the under hood canister.
From what I've read in the forums, it seems I could chase this until I've replaced everything. Bleeding on a 20+ year old XJ every spare moment is starting to lose it's shine. :gee:
Any helpful suggestions?
Thanks