1992 XJ6 with 165k miles

Recently fixed some oil leaks by replacing the timing chain tensioner gasket (and put in a new tensioner) along with the valve cover gasket. While doing this, I went ahead and replaced the spark plugs with Champion (checked the gap before installing them).

Car ran fine for a short time and then starting being problematic when accelerating. It will idle smoothly whether in park or stopped in drive. As soon as you press on the accelerator, it will begin to hesitate like is missing.

The coil, wires, cap, rotor, CPS and fuel pump are all new within the last year. I swapped out the plugs for another brand just in case but there was no change and verified the wires with a multimeter. I’ve checked for vacuum leaks, the air filter is clean and I changed the fuel filter but still the same symptoms.

I put injector cleaner in the gas tank and need to run it a little longer to see if it will make a difference (original injectors at 165k). I am also planning to pull the throttle body and clean it.

I’m looking for any other suggestions. I’ve checked the vcm and there are no codes. I feel like many of the things that could cause the acceleration issue would also cause a rough idle and/or throw a code.

 

Try a new fuel filter, sounds like gas starvation ..maybe you have a blockage in the last one you fitted? I'd also check the connection at the maf.

 

Thanks - I can pick up a new fuel filter and try it. I did pull apart the air intake including the maf which I cleaned before re-installing.

 

here's a video of what happens - idle is fine but any gas and it stumbles

 

Got the new fuel filter and installed it but the condition is the same.