It's a Grand Cherokee 1998 4x4 , 8 cyl, 5.2 lt california and us emitions.
It has a strange failure, only when is hot, (after 20 to 30 minutes working) start to shake and have several explosions.but engine keep on working only in idle mode, I change the cap of distributor and the coil. It is not inyectors because it only happens when is hot, also alternator amps are below 13.6, My mechanic said is the engine computer because the alternator regulator also is placed there, we change alternator and battery and every thing was the same. thats why we are going to the computer, could be any other thing?
2006-08-10 07:04:04 · 5 answers · asked by javiercinni 4 in Cars & Transportation ➔ Maintenance & Repairs
check fuel pressure,plug wires,injectors,computer freeze frame,and miss history.tap on computer and see if smptons change.
2006-08-10 07:22:56 · answer #1 · answered by gear head 2 · 0⤊ 0⤋
back fires when it's hot engine idles unevenly. Sounds like you have a cyclinder that isnt' firing. Since it's when its hot I'm gonna say when the engine heats up and expands somethign is shorting out. Backfiring means there is unburned fuel in the headers. So i'm gonna guess and say bad plug wires, or caps, or distributer cap. do a spark gap test when the engine has the problem. or just pull each plug one at a time when you pull a plug and the engine shows no change thats your culprit.
2006-08-10 14:31:01 · answer #2 · answered by Briggs 3 · 0⤊ 0⤋
Sounds like a misfilre. Could be a bad ignition control module, ignition coil, or the computer. You should get a mechanic that will diagnose your vehicle when it gets hot to find out what is wrong and not waste your money just swapping out parts.
2006-08-10 21:36:43 · answer #3 · answered by Carpet Shark Luver 4 · 0⤊ 0⤋
are you loosing oil too? They've got a problem with the intake plantum leaking oil into combustion chamber and causing a spark knock. you should notice it blowing blue smoke out the tail pipe when this happens. If not, then you may have carbon built up on the piston and causing it to pre detonate.
If it's the oil leak, the intake plantum gasket will have to be replaced.
If it's the carbon built up, you can pure a spoon full of water down the intake to knock of the carbon.
2006-08-10 14:20:13 · answer #4 · answered by michael081278 4 · 0⤊ 0⤋
Do a compression test
You may have a burnt valve
After getting Hot if you have a burnt valve it won't seat
2006-08-10 14:23:28 · answer #5 · answered by Vulcan 1 5 · 0⤊ 0⤋