ART HERNANDEZ

My 1995 Grand Cherokee 5.2L started sputtering and then died, the next morning started just fine but did not drive it. While trying to fix I checked the fuse box, all looks OK, changed the coil and still engine cranks but wont start. I got no spark and no fuel. I can hear the fuel pump come on when I turn the ignition, I poked the fuel valve to see how much pressure is there and I saw a few times that only about an amount equivalent to a teaspoon came out with no pressure at all. I mean.. my lungs can create more pressure than that. Does anyone know if the ECU detects no spark signal it then in turn cuts off power to the fuel pump? Any help please... short on cash!!! THANKS!!

Cherockee

Replace the Crank Position Sensor.

peterk

CPS X2. (Cranks Position Sensor, Second Opinion Agrees.)

ART HERNANDEZ

Does anybody know why the fuel delivery shuts down on my 95 grand cherokee 5.2L when the Crank Position Sensor goes bad?

JJCIII

The cpu will not tell fuel to flow and spark to fire if it thinks the engine isn't turning

CrazyMacaw

No pulse signal from CPS to the ECM will cause ASD (Auto Shut Down) relay to kill power to the fuel pump and ignition. It's a safety mechanism (handy for fire prevention in an accident), basically if the engine quits turning the pump stops pumping.

ART HERNANDEZ

After a few cuts and bruises and some choice words, I replaced the CPS on the 95 grand cherokee 5.2. After it was replaced I left it running for about 20 minutes and ran perfect. I would like to thank everyone who responded to my question. I appreciate the help from all of you. Greetings from sunny San Diego CA. OHHHH and how much did it cost? $190.00 for towing, coil (which I did not need) $27.00, CPS $54.00.

peterk

Art,

You did well; it runs.

In my case, I was not as smart as you at sensing that the teaspoonful of gas was so little as to mean no pressure. When I suspected the coil, an ohm meter quickly ruled that out. I was at home, in a city, Fairfax VA, that has many, many car dealers, chain and independent shops. I called a dealer mechanic, whose work I much enjoy, and he told me it was the CPS, but he was off on Saturday. So, I used AAA for the tow (free), and the local shop got me on the road in an hour or so. $296. One of two no-starts in the 17 years of owning it. The other was a fuel pump.

Btw, the earlier Cherokees have different CPS technology than the later ones, and diagnostic tests are also different. In your case, it sounds like you were brave enough to go with the 99% guess.

best,

Peter

rbrweb

I had the same problem and took me to change fuel pump, then tps and cps, but find out that the Jeep ZJ models from 96 to 98 has the same stalling problem, the isue comes from some circuits on the ECM that doesnt make right contanct to deliver the proper voltage thats why when you get to the ECM and move the conections your ZJ starts and later when it gets warm again it stalls.
Solution: change the capacitors on the ECM, clean up terminals and have a visual inspection checking that everything is in the right place, i mean no lose solder ends etc. this is going to take you a lot of time and patience.
Best Solution Go to your web browser and look for a new ECM, you will get it for 150 or less in very good condition. Thats what i just did and now it works perfectly.
Hope this helps.