i've got a 92 dakota 4x4 with sumpin fishy going on! about a year ago it died for no apparent reason. it started after waiting 10 minutes. just recently the problem's occured more and more frequently. i've put a new TPS sensor in and it runs great, but still shuts down occasionally. 2 weeks ago, a friend of mine helped replace the fuel pump unit. it ran great for a couple days, now it quits on me at least once / day. it acts like it get no fuel! i can't hear the pump prime at all since replacing. is the ECU sending bad info to the fuel pump? i don't think my "check engine" light even works! so i can't check codes. i'm frustrated because it's got 163K on it and runs like a beast (until it unexpectedly shuts off).
help!!!!!

 

one suggestion i'd recommend is when it dies and wont start, jumper the fuel pump on the fuel pump relay so it turns on, then try to start it. if it starts then either the relay is going bad or possibly the PCM. the pcm will drive the relay to close it's contacts to turn the pump on.

one other thing it could be is the crank position sensor.

 

the fuel pump relay is new, they're cheap enough i bought 3 extra! are PCM's $$$$ ?

 

if you do what I suggested, you'll know if it's the pcm or not, it could also be the auto shutdown relay... (just thought of it). the thing is when it's dead and wont start, you can turn the key on and listen for the pump, if hte pump turns of for 2 sec but wont start, then the signal going to the relay to turn the pump on. this will help narrow it down some.

most of the time however it's the crank sensor. when they start to go bad, they will get hot and shut off the motor in a heartbeat.

 

ALL of the relays in that particular box are new. I'm hoping it's the crank position sensor.
today as i was running an errand at work, it died after about running great for 15 minutes. i didn't notice right away, so my foot was about halfway down. after a second or two it popped back to life. about the time i looked to confirm zero RPM's, i saw it jump from zero to normal driving.
what the hell?
by the way Steve, thanks for the help.

 

sdavis 531,

Did you find the solution yet?

I have the same problem. Truck cuts off. Sits for a while and it will start (sometimes) then runs for a few seconds and cuts off. It always turns over. Have not started the troubleshoot process yet.

 

It seemed to have fixed itself for about two weeks. the crankshaft sensor seems to be my next option. i found info on testing it...i got zero continuity from the sensor so i'm replacing it soon. it doesn't look too bad, just kinda tight.

 

Well fellows,

So far I have swapped the relays, replaced rotor cap and button, replaced AIS motor (needed), and plugs. I also removed the wrap from the loom of wires under the box that contains the relays and soldered the splices even though they looked just fine.

Yesterday it cut off on me again. This time my 6 yr. old was with me. I had her turn the key after I pulled a plug wire and grounded it with a screw driver. NO SPARK! I reattached the plug wire and waited about 10 minutes and it started and ran fine for the rest of the way home. Just like last time.

I guess I will try to test the coil, crank sensor, and SMEC.

 

Found the problem. It's the PCM (SBEC). Unfortunatly I found the problem after I replaced the HALL effect, Crank Position sensor, and coil.

I tapped the unit and the truck shut off. I had previously removed the wire harness and it looks tip top. If I tap the lower right corner, the truck shuts off. Must be a short inside the gel.


Chrysler P/N: 56028339

New part #: R488661

95 Dakota, 2wd, auto, 3.9L

 

replaced the crank sensor, not bad except i had to climb on the motor to plug the damn sensor in. i'll know in a couple weeks whether or not it did the trick. i'm thinking bout the AIS motor (idles too low when warm). i'll check the wire loom shortly (it seems 2 b a popular fix). hopefully i won't need the ECM.