Jeep starts then dies instantly

[sebasshole]

Hey everyone i have another problem.
So today i got stuck yet again. and instantly the truck died.
The truck will start but dies rite away. Sometimes if i hold the gas down it
will rev up, and will stay if i keep the revs above 4500 RPM
So i got the truck out and home and i let it sit to dry for a couple hours.
The truck will still start and die. iv been doing some research and theres alot
of info but everything says something different. im hoping my local forum can help
me. its a 88 jeep cherokee LTD 4.0L 206 000km
I appreciate all the help everyone.

[fug]

My guess is ... Crank Position Sensor.  I've had similar type issues in a couple of my XJ's and it was the CPS.  Turn the key on the engine fires... revs up and dies right away.

[Immortal]

x2

[dunl]

Cubed.

[sebasshole]

yes if i turn the key and hold it to the start position it will run, but if i give it throttle
the truck will die. Still the crank position sensor? And if so where is the CPS sensor?
I guess step one is to clean it and see if it works, 2 is replace it. 3 if that doesnt work
keep searching. Im gona try tommorow thanks for the help Everyone!
first forum i have ever been on thats local and actually helps within a couple hours.
Iv been on forums where iv waited for days for a single reply or tip lol

[sebasshole]

Sorry, if i turn the key and hold it. the truck will stay on and rev,
but if i put it into gear it will die.

[fug]

You have to hold the key in the start position to keep it running?  or it just stays running on its own til you give it any gas?

If thats the case then its not the CPS.  Bad CPS = turn key sounds like it starts but dies immediately.  Doesn't matter what you do with the gas... it just dies.

[OffRoadNewbie]

it sounds silly but slam your rear hatch door and try again ......... mine didnt like to run with the rear hatch open a bit

[Immortal]

that IS weird....

[barmanjay]

change your fuel filter

[cLAY]

Ballast resistor for fuel pump.

Its located on the fender wall near the airbox. Looks like a white porcelain box with two wires on it. Make sure one didn't come off.  Try connecting the wires directly together.

Its purpose is to reduce the voltage going to the fuel pump to make it run quieter. Early model XJs had consumer complaints  about noisy fuel pumps. This was done as a cheap fix to quiet things down. When the key is in the start position the ballast resistor is bypassed and pump recievies full 12V. In the on position the power for the pump goes thru the resistor kicking down the voltage and making it quieter.

After the wire jiggled off for the third time on my '89 XJ from bouncing on the trails I just connected the wires together and bypassed the resistor. No more problems.....

[barmanjay]

next thing to check TPS

[ogilviexj]

Sounds like TPS to me too

[sebasshole]

So i changed the distributor.
cleaned all the plugs.
cleaned the tps sensor
throttle body
and the other sensor on throttle body

now it wont even start just turns over.

next is the cps sensor.

Anyone know a cheap backyard mechanic that i can take this too.

its my daily driver that doesn't work lol

[S-FLY]

Check the CPS first.