'95 Jeep Grand Cherokee Laredo 4x4 (bought used 3 years ago), The Jeep sometimes dies while we are driving it. Most of the time we can restart it right away, but others it will make the turning over sound and not “catch” & go vroom.
Other times we’ll be driving down the freeway (for example) and it will do a little shutter, like it’s going to die and if we push on the gas it kinda skips over the dying part.
We thought it was the fuel pump, so my father-in-law took it to a mechanic and he checked it out and said the fuel pump is fine. His assistant drove it around for a while & it never died on the (of course). So he said it was fine and suggested we got some bad fuel and told us to put in some Chevron, but later that night we drove it close to home for 20min & it worked just fine. Ate some dinner at Mom & Dad’s then it wouldn’t start up again.
We’ve changed the Fuel Filter, it has a new Radiator, New Brakes and Just got an Oil Change, we filled it up with Regular Chevron and added ‘HEAT’ (additive to help get rid of moisture)… We are at a loss… Please help!!
The problem might be caused from a faulty ignition module.
Open the hood and look at the coil on the fender well. The ignition module is located below the coil.
Without knowing if the problem is fuel or spark related (and I agree with Tester about the ignition module) the fuel pump could still be at fault.
Pumps can test fine and may work fine for days, weeks, or months and decide to die.
Once the engine stalls it may start right back up again; or not. It varies.
I’ve cut a number of erratic pumps open and they all seem to have 2 characteristics.
One is a worn armature commutator that may look fine to the naked eye but horrible under a magnifying glass.
Two is the armature shaft will be badly worn at the end that drives the pump impeller. Like the commutator, the shaft will look fine to the naked eye but under a magnifying glass it will be cratered and look like the Moon’s surface.
Try spraying some aerosol carburetor cleaner into the intake and see if it starts and runs for a few seconds. If it does not then it’s a spark (module) problem and if it does run then it’s pump related. That means either the pump is dead or there’s a control issue (electrical) with the pump. Hope that helps.
I have a 2003 Jeep Wrangler Rubicon and the same thing happens to me. I have replaced the fuel pump and I have replaced most of the wiring to the fuel pump. The problem is still there. Any suggestions?
We ran a diagnostic and it was pointing to the Crankshaft positioning sensor. So we replaced it and now it works great!! No more problems!