yikes

Well tonite it finally happened. My 99 wouldnt start, just cranks. Unplugged crank sensor and plugged it back in and it started. I know that it has to be replaced. The big question is how many more starts will I get before the sensor dies completely ? No time to replace it until this weekend.

RatchetMaster10

No way of telling you, sorry man. Any electrical sensor can work fine one minute And be completely dead the next. You could 30 more starts or 2.

RatchetMaster10

Also to try and eliminate a connection problem. Put some die electric grease or vaseline on the connection

DFlintstone

X2^ You might have fixed it!

Just in case there might be other "gremlins" there's this:


1984-1990 w/AMC engine are pre-OBD.

1984-1986 w/GM V6-173 are OBD-I (GM control setup.)

1991-1995 are OBD-I (Chrysler)

1996-2001 are OBD-II (Chrysler)

The "Key Tricks"
Older (OBDI) models - Start with the ignition off. Within five seconds, switch the key on, off, on, off, on. ("On" is NOT "Start" and "Off" is NOT "Lock"). The "check engine" light will flash. Count the flashes. Each code is a two digit code, so a (for example) 23 would be FLASH FLASH (pause) FLASH FLASH FLASH (long pause). It will never flash more than 9 times, so watch for those pauses!

Newer (OBDII) models - Put the key into the ignition, push down the odometer reset button, then turn the key to RUN with your finger on the button - and then release the button. The odometer will go through 1111111 through 999999, then display the car's serial number. It will then show the error codes (it might show them starting with P). If this method does not work, try the OBDI method.

yikes

[QUOTE=RatchetMaster10;1448565]Also to try and eliminate a connection problem. Put some die electric grease or vaseline on the connection[/QUOTET

Thanks, just went back out and put some die electric grease on the connection and it started 20 - 25 times. I should change it any ways, right ?

DFlintstone

"I should change it any ways, right ? ". Let me know how it's running next month and I'll answer that. No idea myself. It might have been the connector. (happens). I think there is a resistance test for it. MIGHT tell you something.

RatchetMaster10

It wouldn't be a bad idea to go ahead and change it

tjwalker

Absolutely change it. Especially if it is the OEM sensor. I am about to change the crank sensor on my 99 as a preventative measure.

Much easier to change it in the comfort of your garage or driveway than to have it crap out on you when you're on the road or trail. It isn't particularly easy to do this repair unless you have the right combination of extensions and a wobble joint on the end.

And unless you like doing things twice, buy a genuine OEM Mopar crank sensor. You absolutely will get the best reliability and longevity with theirs. Lot of hit and miss with aftermarket sensors. And considering that the crank sensor is the most critical sensor on the engine, it is well worth the extra money.

RatchetMaster10

Agree, your gonna need several extensions and a wobble 11mm socket on the end. Also agreed that you should get mopar sensor. I've been thru 3 aftermarket sensors till i finally got one from jeep.

tjwalker

Exactly. I see threads with stories like this every week.

I buy plenty of aftermarket parts (just bought some today), but I buy my crankshaft position sensors EXCLUSIVELY from Jeep!

prerunner1982

Be careful not to drop the bolts into the hole for the CPS.. bad day made worse.

Also, a trick to make it easier to change in the future is to cut the holes in the mounting bracket into slots so that next time you will only need to loosen the bolts, not remove them. (disclaimer: This is most likely to void any warranty on the part)