wlprice

About a month ago my xj began occasionally turning over and not starting when I went to start it. If I gave it gas, it would start, if I let off the gas, it would die. After it ran for awhile it would run normal. I cleaned the TPS and changed the fuel filter, but I'm still having similar issues. Most of the time it starts and runs fine, but sometimes the power comes on but it won't turn over at all. I tried starting it in neutral to see if it was the NSS and that didn't work either. If I keep messing with it, it eventually starts and runs normal. Also, sometimes the motor will die out of nowhere when I'm driving. I have no idea what could be causing this any help would be greatly appreciated. Thanks

HappyTrails

Remove and clean the idle air valve, just inboard of the TPS. Be careful not to bust the screws removing it. Factory used locktite stuff.

Clean the module and the seat inside the throttle body right where it screws on. I will bet that will help.

Also, check for any faulty vacuum lines and connections. For test purposes you may want to just cap them all off at the manifold. See what happens and then reinstall one at a time to find a possible culprit.

Hope this helps. Been there myself.

wlprice

Thanks, I will give it a shot. The reverse lights aren't working either so maybe the NSS is involved somehow as well

HappyTrails

I had problems with reverse lights too. Removed, dismantled, and completely serviced the NSS. Reinstalling NSS can be tricky. Before securing final adjustment on installation, be sure to check the reverse lights. If they function they kind of indicated a proper position of the NSS. But not necessarily. I had over greased the internals of the NSS and that caused some continued reverse light issues regardless of position.

Completely servicing the NSS is not difficult. And it will help eliminate a bunch of problems. These units are not well sealed, and if your XJ has been mudded or forded real deep, you could have contamination issues inside the NSS.