Hey guys. I don't really know where to start without throwing parts at it so here it goes.


1999 XJ. Golen 4.6 Stroker, 24lb injectors, 62mm TB, Headers/3" exhaust Accel coil, Spectre cowl intake, Auto, Np 231........

The Stroker and pretty much everything under the hood has less than 20,000 miles on it. Sometimes randomly (doesn't matter temperature/speed/rpm etc) the engine will stutter like it is not getting fuel and the RPMs will go all over the place. I drive about 20 miles to work and it usually happens once in that time frame. If I'm at a stoplight when it happens, it dies. If I'm driving, I can floor it and it will go away. This started happening after a trail where you cross a river 40+ times. Ran excellent before that.

What I've done- Swapped sparkplugs (used colder ones and its running a bit lean as Golen recommended) new airfilter, cleaned out clean TB, and new 02 sensors. Distributer/wires were all changed with motor/dielectric greased and are dry. Ran a can of seafoam through it.

I have no leaks, no water in oil/tranny- engine runs superb the rest of the time. I have replaced about everything at one point or another except the TPS and the FuelPump. (including CPS about 2 years ago) I am leaning towards either one of them but neither are really cheap AP before I start throwing parts at it, I wanted opinions. Fuel pressure is fine BUT I cant really check it during the few seconds it happens.

Thanks!

 

bump

 

Acts like a TPS issue.

 

Cool thanks! Ill go grab a new one-

If I were to have to get a fuel pump, any brand recommendations?

 

Bosch.

 

so I ran the codes- PO443, P1391 (x3), P0705 ( which I've had forever and have never been able to find a fix)...


I guess that cps might not have liked being under water so much huh?

 

Ty

 

Upon further research, the p1391 is not likely to be the CPS. I cant seem to find a cam sensor anywhere for a 1999 so i guess Ill check the harnesses/voltage and if all is correct there, buy a new distributer correct?

*edit* is the "camshaft position sensor" the same thing as a stator/ignition pickup on mine? If so, might just buy an entire New distributer at 30-40$ more. Thanks a ton!

 

YOu need the "submarine" option.

 

Haha if only there was one... Am I on the right track though? probably time for a new distributor?

 

Or just the sensor maybe. I think you're on the right track.

 

I sometimes have both of these symptoms...for me the studdering is low battery volts, usually when the alternator is producing about 10 or less volts, causing the spark plugs not to fire well(kinda makes my car bog down substantially). What does your volt meter say??

The rpm spike definitely sounds like a TPS issue, don't buy a low quality TPS if you're going to replace it (been there done that), the TPS is one of the most important sensors the computer needs to run the engine and it needs to work perfectly, the output volts of the TPS need to be accurate and gradual, China/amazon knockoffs aren't the best idea

 

Know what else you ought to do?

Unplug every connector in the engine bay and spray it out with contact cleaner.

 

I bought the most expensive TPS Rock- Auto has to offer (before I read codes) haha. I don't have any electrical issues when it happens (lights dim, stereo etc) but I do have a bunch of stuff hooked up to it... might be time to upgrade alternator/main power/ground wires... I haven't checked the voltage yet but I will. I just think something is malfunctioning as it never happened before. The stroker ran flawlessly.

Thanks for the response!

 

I actually just bought some cleaner/ wire dryer/ dielectric grease today to do that haha.

If it comes down to it, know of any decent distributors? I almost bought a Mallory when I did the Stroker... they no longer offer one and I don't know any other decent performance distributor manufacture.

Assume most of the parts store brands are either going to be made in China or remans.