1995 Jeep Grand Cherokee Laredo. Plz help tried everything!
1995 Jeep Grand Cherokee Laredo 4.0 liter strait 6 motor.
Ok, see if someone can figure this out because everyone I know is stumped. I've asked a few mechanics and parts store personal and no one knows.
First I need to explain the problem. After driving for so long, say 25-30 miles, it starts to act up as if it was running out of fuel. Backfiring, cutting out, loss of horse power ect... It does it whether you try giving it a little gas or the whole petal. But it only does it after being driven for awhile and its hot outside. When the temperature outside cools off and during the winter it doesn't act up at all. When it's not acting up it runs great and no problems. Sometimes I can put it in neutral and turn key off and back on and it fixes for a short time. Other times I have to actually pull over and turn the jeep off and let it sit for approx 10 mins and it's back to normal again for a short time. It's not showing any warning lights inside of any kind. There are no vacuum leaks that have been found after several times looking and listening. My theory is something is getting too hot I just can't figure out what. If someone could please help me I would for ever be grateful.
This is a list of things I have tried so far:
Pick up coil
Fuel pump relay
Crank shaft position sensor
The air filter is new as well and gets regular oil changes. Also it has proper fuel pressure and I have tried cleaning intake and has had probably 6-8 bottles of either Seafoam or Lucas fuel treatment since problem began. I'm not very wealthy and this problem is beginning to become pricy.
When was the EGR and o2 sensor last replaced? Also relays are sensitive to temperature (since most are mechanical). I've never had this issue on two (88 & 95) Cherokees and a 95 Grand. Though on one 86 BMW 325e I had, it would act up in the summer because of a faulty main relay that controls the ignition system. And a customers 98 Dodge Neon because it had poor battery cables. Check you sparks plugs again, even it if new, one could fail. Check for brown burn marks on the electrode. It could have a small fracture that grounds out at higher temps. I'm surprised that your not pulling any diagnostic trouble codes. Or have you tried that yet?
Sounds like a bad computer worst case scenero. Think about it computers need to stay cool or they start gettin kookie... just a theory. b/c you know it aint mechanical
Having a similar problem. Only mine stalls out completely after 25 miles or so. My Jeep issue is the auto shutdown relay killing power to the coil. Not sure why yet. (possibly computer) However- that also may cause it to backfire if it is losing spark and regaining spark and igniting the gas vapors that made it into the exhaust. Also, the 4.0 doesn't have an EGR, but does have two o2 sensors.
Maybe try replacing the thermastat. Or taking it out all together. It could be sticking and telling your computer to turn the vehicle off because it thinks its overheating. This fixed my 1985 jeep laredo. my 1995 is shutting off regardless of the dang wweather. I think mines actually in the comp.
I worked on a wrangler that had thash in the fuel tank. The trash would slowly clog the sock at the bottom of fuel pump. When it would stall, the trash would kinda float away from the sock....eng. would restart, run for a while and die again....this was a fun one to figure out. Hope this helps.....
My jeep did the exact same and what fixed it was the main computer brain on the left side firewall seams like it was around 300 bucks
Hello, None of the above, I have had this problem 3 times in my life, once in a corvette, once in a ford pickup, and now in my 95 Cherokee, the fix is simple, there is a ceramic module in the bottom of a electronic distributer that over time will crack internally and separate when it get to a certain temp, that will cut the spark to the plugs, when it cools off it will make contact again and the car will start and run until the module get hot again. I hope this helps all you shade tree mechanics out there.
I'm dealing with the same problem on my 95 jeep. I have replace spark plugs, wires, cap and rotor, idol sensor, and fuel filter. I was told by a mater mechanic that it could be my PCM. But first I want to try replacing my auto shutdown fuse first. Have you replace your auto shutdown fuse located in the fuse box under your hood? Drixcy
It was the manafold gasket causing all the problems. That year was prone to the manifold breaking. Check for leaks on or around your manifold and I bet you solve the problem.
This is exactly what happened with mine. It's gotta be your fuel pump because when you throw it in neutral and turn the key on and off a few times you are pressurizing your fuel pump which is why it seems to run just fine for a little while. Definitely get that changed.
It sounds alot like the problem alot of people had before plastic fuel lne and fuel injection. " vapor lock" however its not supposed to happen with fuel injection or plastic fuel line.
So ive read all the answers to the problem im having the fuse box under the hood has 6 tiny fuses and one is to the fuel always keep an eye on that one...to continue i was driving home and my head lights flickered then went completely out so i turned the knob and lost all power lights everything there was nothing, had to trailer it home, now ive had to change all the bulbs in the entire jeep, changed the instrument panel,the light switch, every fuse in both boxes,,,and relays, and the computer brain.....after all this you woulf think the damn thing would start well it does but dies almost immediately ive checked the plugs wires and distributor, replaced alternator and i still cant figure it out any suggestions would greatly be appreciated....thanks ladytj
Waynethor1 could you please specify to me where is this ceramic module exactly? I have the exact same freaking issue with my jeep grand cherokee laredo 95 strait 6 4.0 .... x.x
It is your radiator or your carborator I have th same problem of it could be a short in a wire some where no code right mine either after a lot of time and money it work great now good luck with it.
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