Wifes xj making bad noises...bad for me too.

the wifes 88 xj has shut off on her a few times letting her wait for 15-30 minutes before it will run again. In the mean time it will spin over just not run. Also ran and shut off then cranks and fires roughly making sputtering dieseling sounds and not able to rev the motor. Has new cps, o2, dont know how old the computer is. Engine is rebuilt and has performed flawlessly for the year that we've had it. Its acted up like this twice in two weeks. YOU ALL KNOW HOW MUCH CR@P I'M HEARING ABOUT THIS. PLZ HELP. THANKS Travis.

Check the crank shaft positioning sensor???

Maybe the map sensor?
Just a guess.
You might check codes too.

It could be a bad/worn out Throttle positoin sensor (TPS). Also on the 87-90 XJ you have to calibrate the new TPS, just follow the procedure posted in the past day or so.

Also with the MAP sensor make sure the tube is connected to the sensor and to the throttle body.

Well the cps is really newish, less than a year old. Map sensor seems to be reading right (put it on the snapon scannner at work) Silly old 88 xj wont spit out trouble codes like the chry.xj's will. I'll double check the map sensor connections in the morning and I have a spare I could try. The tps I will check too. How do you check a cps to make sure its good. It really feels cps-ish, is there a module in the distributor that could cause super ocassional no start and funky running? It has to be running for a while to get it hot enough to start the problem.

It's that damned brush gaurd! :laugh:

Really,though,my wife's 2000 XJ does sort-a-kinda the same thing. We can be driving down the road and the engine will just stop. No warning,no nothing. The engine dies suddenly,the tach drops to zero,and then after a couple of seconds it will magically spring back to life :dunno: I've been meaning to get Andy to investigate it for me since it's more than likely out of my realm of shadetree mechanic experience. Probably is the TPS,though. When you replaced yours,did you use an OEM unit or the Auto Zone special? That *could* be the problem if it wasn't an OEM piece,of course,ours is an OEM "piece" too,but I won't get into that! :laugh:

Yes, there is a modules in the distributor, and that's the next thing to check.

You could also pull the coil module and have Auto Zone check that.

thanks all, will be checking zhit out today, let you know if I find something.

Two things come to mind. First you 88 has the evil c101 connector through which all sensor signals pass including the cps which is probably the problem. The c101 is on bulkhead above engine on drivers side. Clean and tighten all contacts therein and relube w. dielectric greas. Second is could be the cps wire harness connector (not the cps itself since it is new). IMHO, either the c101 is degrading the signal strength or your cps wire harness connector is bad and is degrading the signal. Below is info on rebuilding the cps wire harness connector I have posted before:

"If on a crank but no start the unplug and replug of the cps wire harness connector gets you going you may just have a wire harness connector going bad and may not need to replace the cps sensor. Here is how to test: hook volt meter to both wires from cps sensor w. harness unplugged. Set the range on meter to less than one volt. Crank engine and if cps generates .5 to .8 or more volts it is ok and your connectors need tightening or replacing. I got my parts for a couple of $ at pepboy but advanceauto.com also has them. They were made my Dorman under the Motormite Conductite tech grad name # 85303, 85304 and 85305. There are about 5 pieces in each box. You can also get a small tool set that helps on the install number 85360. I fixed my 89 this way a couple of months ago when I got tired of unplugging and replugging the connector every few weeks. My cps was only 1 yr old so the engine side harness connector part was worn out. I replaced both the female and male side internals of the connectors and it not only starts every time but the idle was also improved. Greg "

Greg

thanks all, the cps has the optional factory fix where they by passed the wiring harness and wire it straight to the computer. cps plugs into a new connector through a new grommeted hole in the firewall and plugs straight into the computer. I've seen alot of fixs for the cps connections and read about this on but its the first I've ever actually seen done this way. I'll work on testing it and the connections this morning. Thanks for all the help. I'll keep you posted.