How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask rpmdiag Your Own Question
rpmdiag, Tech and Instructor
Category: Oldsmobile
Satisfied Customers: 8075
Experience:  Since 1975
Type Your Oldsmobile Question Here...
rpmdiag is online now
A new question is answered every 9 seconds

I am trying to get my fathers old Grand 94 V8 running. It

Customer Question

Hi ***** ***** my name is ***** ***** I am trying to get my fathers old Grand 94 V8 running. It wont run but it is starting fine, has fuel pressure at the rail and good spark
JA: Thanks. Can you give me any more details about your issue?
Customer: This is 94 jeep grand Cherokee with 5.2 V8, it was running fine until resenty. Then you could get it running by turing the key on and off a few times, start for að few seconds and the start again and then it would run fine. I have replaced the PCM but it still wont run, any Ideas ?
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: Oldsmobile
Expert:  rpmdiag replied 1 year ago.

Hi, I’m Ron and I can help you.
I have been in this business since 1975 and also teach automotive repair. I am confident we can resolve your problem together. Please understand that I don't know your skill level. I can't see, smell, hear, or touch the vehicle either, so it may take a few replies to get to satisfactory results. Please be patient!
I also try to give all of the information you may need, expecting a “positive rating” in return. I will also continue assisting you after you have rated me, if necessary. If there is any reason I cannot get a positive rating, please let me know why “in advance”, so I can go another direction for you. I am sorry you’re having this problem; I’ll help you through it.

I'm sending you an attachment that covers every aspect of what it takes to run a motor. Please read it and do ALL the recommendations with the proper tools.

Thanks, Ron

Customer: replied 1 year ago.
Hi RonaldI have a 20 years experience in conntrol engineering, plc programming and automation. Also I have been mostly fixing my own cars since i was a teenager.I have checked all of things on the list and it all checks out fine. I have replaced the PCM, got a new one from FlagShip1 but that did not get the Jeep running. The fuel pressure is good, good spark, no security active, good compression.
The test in the "check engine" only gives the code 12 "battery disconnected" and 55 end of code for both the old PCM and new. I have tried to use start spray to get it running, but no luck yet, All the relays and fuses are good.This problem begun by the Jeep was difficult to get in running, you would have to start it a few times and the it would get running an then it would run fine, but now that "trick" dont work no more.My feeling is that this is a electrical problem that has something to do with ADS relay, the is 12V dc between the terminal 87 and 30. Should I try to connect a wire between terminal 85 and 86 ?Can you provide me with electrical drawing of the PCM ASD connection ?Is there a OBD port on this Jeep because I have not found it yetThis is a 1994 Jeep Grand Cherokee V8 5.2, VIN numer is 1J4GZ78Y5RC349040Hope you can helpBest regards
Sveinn Logi Gudmannsson
Expert:  rpmdiag replied 1 year ago.

It wouldn't be the ASD relay, or you wouldn't have spark and fuel. The connector for the scan tool should be L shaped and by the battery.

Thanks again, and please don't forget to rate me and keep this link in case you need me again later on. I will do more research for you and let you know if I find something else.