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Chris (aka-Moose)
Chris (aka-Moose), Technician
Category: Jeep
Satisfied Customers: 48357
Experience:  16 years of experience
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My name is ***** *****. I have a 2000 Grand Cherokee, 4.7,

Customer Question

My name is ***** *****. I have a 2000 Grand Cherokee, 4.7, auto, 143,000 miles. The engine dies occasionally, when it dies the fuel pump does not run. I rigged a jumper to power the fuel pump when the engine died. the next time it died I used the jumper. I could hear the fuel pump run, engine turns over, no start. apparently the problem shuts off fuel pump and injectors (spark?). After cool-down the engine starts immediately and runs perfectly. It seems to show the problem after an hour or so of run time. the cool-down can be 5 to 45 minutes. It seems to take longer to cool down each time it dies.
JA: Thanks. Can you give me any more details about your issue?
Customer: yes, I have replaced every relay related to engine run or fuel, have swapped out every fuse related. I rigged a test light inside, so I can tell if the fuel pump looses power, It does loose power to the fuel pump. I have taken loose every ground (I think) to ck for connection. I replaced the ECM with a known good from another matching Grand Cherokee. No codes set, the "ck eng" light does not come on. I did replace the crank sensor about a year ago, engine displayed a very different problem with that, with a "ck eng" light.
JA: OK got it. Last thing — Jeep Mechanics generally expect a deposit of about $18 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: Jeep
Expert:  Chris (aka-Moose) replied 1 year ago.

Welcome, I'm Chris (aka Moose). Experts aren't employees / agents of Just Answer. We are independent service providers using the Site to sell their Expert knowledge to Customers. I strive to provide EXCELLENT 5 STAR service, let me know what's needed from me so your pleased.

When this happens does fuse 12 under the dash lose power with the key on?

When this happens is the PCM no longer grounding the brown wire to the pump relay with the key on?

Can you see what else it is missing, spark or injector pulse when this occurs?

Below are the diagrams I will be using.

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