1989 Jeep Cherokee Wont turn on

Tiny
JAKEW10
  • MEMBER
  • 1989 JEEP CHEROKEE
  • 4.0L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 173,000 MILES
I recently purchased this 89 jeep Cherokee, it drove home fine. I also took it to the store and back fine. The jeep soon after cut out while it was in idle, I figured it was just out of gas and filled it up and it ran fine for about 2 more miles until it cut out again. This time in a parking space, figuring the battery was dead I had a friend jump it, and it turn on fine, but on the drive back, while I was giving it gas, the jeep died on me again. Tried jumping it for a second time, but it didn't work. I had a few friends look at it, and I got two answers, it was either the alternator or fuel pump. The next day I tried charging the battery for 10 minutes and it turned over and started up on the third try. The engine ran for about 10 minutes and died again on its own leaving me to think it was an alternator. I purchased a new alternator and installed it. Tried jumping car again for ten minutes and turning it on, with no result. I brought the old alternator and battery to auto zone and had them tested only to find out they both worked fine. So besides wasting money on a new alternator, I have no clue what the problem is. I would really like to get this thing on the road again, but I need some help. I am a little strapped on cash at this point. Hopefully you guys have some ideas. Thank you.
Do you
have the same problem?
Yes
No
Monday, October 13th, 2014 AT 7:15 PM

5 Replies

Tiny
KEN
  • ADMIN
It sounds like the fuel pump is failing, can you perform a fuel pressure test when the engine is not starting?

This links should help

http://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Please let me know what you find.

Thanks for using 2Carpros.com

Was this
answer
helpful?
Yes
No
Monday, October 13th, 2014 AT 7:26 PM
Tiny
CARADIODOC
  • EXPERT
Sounds like you're unfairly blaming the charging system. In your replies, please list exactly what's happening. "But it didn't work" and "with no result" don't tell me anything.

First, to test the charging system, use an inexpensive digital voltmeter to measure the battery voltage while the engine is running. It must be between 13.75 and 14.75 volts. That's just the first part of the test but it's enough to verify the battery won't run dead while you're driving. You need a professional load tester for the rest of the tests, but that isn't pertinent to this story. A good, fully-charged battery, with the engine off, will measure 12.6 volts. If it stays at that voltage when the engine is running, we'll have to diagnose the charging system. You have a GM generator that was redesigned for the '87 model year and is a disaster. We'll discuss that further if necessary.

Next, your vehicle is right in the middle of when Chrysler was buying AMC. AMC used parts from other manufacturers and put cars together with a mix of all kinds of stuff. Chrysler fuel pumps very rarely quit once they've started running, so you'll seldom solve a stalling problem by replacing it. When they fail, they fail to start up leaving you stranded in your driveway. Banging on the gas tank usually gets them going again. You could also have a GM fuel pump. They have a reputation for starting up but quitting while you're driving, leaving you stranded on the side of the road. If you have a GM pump, it could cause stalling. When that stalling occurs, turn the ignition switch off, don't turn it back on, then pop under the hood and check for fuel pressure. There's usually a test port on the fuel rail on the engine.

A better method is to borrow a fuel pressure gauge from an auto parts store that rents or borrows tools, and drive around with it clipped under a wiper arm so you can watch it. If the pressure suddenly drops, then the engine stalls, suspect the pump. I looked up a picture of your pump and it doesn't look anything like the Chrysler pumps I'm familiar with.

For the next part, you did yourself a disservice by removing the battery. That will have erased any stored diagnostic fault codes. At this point you'll have to drive the vehicle again and hope the codes set when the stalling occurs. I said "hope" because the most common causes of stalling often don't set codes, at least not the first time. It looks like you have a diagnostic system similar to Chrysler's. They make it easier than any other manufacturer to read the fault codes yourself. Go to this page for the instructions:

http://www.2carpros.com/articles/jeep-diagnostic-trouble-codes-for-car-built-on-or-before-1995-odb1

The only thing that looks different from Chrysler is having to wait five minutes to reread the codes. On Chryslers, if you think you miscounted the flashes, just turn the ignition switch off and back on once and it will start all over.

The most common causes of stalling while you're driving are the crankshaft position sensor and the camshaft position sensor. They often fail by becoming heat-sensitive, and will work again when they cool down in about an hour. The clue is there will be no spark. You didn't mention anything about checking for that.

You ARE going to have another problem with hard starting and stalling due to the idle speed being too low but we'll take care of that later. The fix is real easy, but in the meantime, you may need to hold the accelerator pedal down 1/4" to get the engine started and keep it running. (1/4" is plenty. More is not better). Disconnecting the battery caused this. While you are going to have this issue, it's not the cause of your stalling problem based on your comment, "but on the drive back, while I was giving it gas, the jeep died on me again". Giving it gas is the clue. This new problem I'm talking about is due to idle speed being too low. The engine will run fine when you're pressing the accelerator pedal.
Was this
answer
helpful?
Yes
No
Monday, October 13th, 2014 AT 8:02 PM
Tiny
KEN
  • ADMIN
Great additional information Caradiodoc !

You are one of our better guys :-)
Was this
answer
helpful?
Yes
No
Monday, October 13th, 2014 AT 8:32 PM
Tiny
CARADIODOC
  • EXPERT
Thank you. You're a wonderful human being. Didn't mean to butt in to your conversation. My fingers were still smoking while you were posting.
Was this
answer
helpful?
Yes
No
Monday, October 13th, 2014 AT 9:01 PM
Tiny
KEN
  • ADMIN
Thank you for the complement, we have a good bunch of guys working work, its a pleasure to be included :-)

btw I never mind people adding to my posts, the more the better!
Was this
answer
helpful?
Yes
No
Tuesday, October 14th, 2014 AT 10:30 AM

Please login or register to post a reply.

Recommended Guides