The truck has 225K miles on it, and runs great and then out of the blue it will act like it is running on 6 of the 8 cyl. the chech engine light came on and the code was a mis fire on #6. It doesnt seem to matter if its warm or cold when it runs rough. The mechanics are scratching there heads and so am I . Now let me tell you what has been done. New plugs and wires New Cap and rotor button New lower intake manifold with all new gaskets and O rings New air filter New spider injector with hose on #6 Timeing check with a computer New uper intake manifold gasket any Ideas would be greatly appreciated.
Looks like you covered just about everything outside the engine.
Since it has 225k on the engine, its possible the valves are carboned up or burned to where one of the intake valves fail to close some times.
You might try a compression test or use a vac gauge when it is running rough. If the problem was not happening before you changed the plugs, you could have bought some defective ones.
Stephen,
I had the mechanic check the compression and they said the truck has real good compression on all 8 cyl. I also asked them about a vac. leak they said they can not find any vac. leaks either. They are going to put in a different brand of spark plug and see if that helps. They also mentioned something about the injectors are controled by the distributor or something like that so they are going to be checking that as well..
×
SOURCE: 95 GMC Jimmy 4.3l W vin rough idle
My problem was solved when I repaired my 4 wd activation dash switch. The switch was contacting on 2WD & 4HI at the same time. The front differential activation is vacuum activated possibly creating a tug of war that didn't actually engage it but drained off vacuum from the engine? A theory at best but stumbbled across it because I knew the switch wasn't working properly I repaired it and low and behold rough idle disappeared and all is good for 3 weeks running.
SOURCE: misfire on #6 and #8 cylinder 1996 Dodge Ram 1500
Check the spark plug wiring . There are several places where the wires cross each other. These wire cross points MUST be at right angles to each other. Or you will have a misfiring problem.
SOURCE: 1989 Cavalier Z24 Stalling problem
Have you heard of Noid lights? You unplug the fuel injector and plug these in and they will light up if the injector is getting power. This might give you a better hint. There are also lights that go inbetween the spark plug and wire. Between these two items you may be able to narrow down the problem to a specific system. I believe that your car has a coil pack. Some of these engines have problems with the crank trigger. I believe it is located on the back side of the motor. If you decide to change it, be careful. I have heard of them breaking into two pieces and becoming a big problem.
SOURCE: 1997 chevy truck running rough
97 chevy 1500 4x4 replaces plugs wires cap rotor dist pick up and crank sensor truck run good when cold as soon it heats up and comes to stop it feels like it boggs down runs rough and stalls any idea what to do?
SOURCE: 98 Chevy Tahoe 5.7 liter engine cuts out and
Have you checked for vaccume leaks?
You've got lots of parts in there, Has the problem been the reason you have replaced all of those, or did it come up while doing some of the repairs?
268 views
Usually answered in minutes!
×