Eddie Don
NAXJA Forum User
- Location
- mountain city tn.
What would foul all my new plugs on start up ? New tune up with dizz cap washed 4.0 before tune up and all was fine tell then . Need help !!::dunno::dunno::dunno:
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Fouled plugs
- Thread starter Eddie Don
- Start date
old_man
NAXJA Forum User
- Location
- Loveland, Colorado
OK, what kind of fouling? Oil or fuel?
Eddie Don
NAXJA Forum User
- Location
- mountain city tn.
Sorry bout that gas !!!
89s15jimmy
NAXJA Forum User
- Location
- mount prospect, il.
got water in connectors. unplug all connectors you can find and dry them out.
old_man
NAXJA Forum User
- Location
- Loveland, Colorado
Ok, now pull all the plugs and show some pix. Are all the cylinders getting fuel soaked, or only one?
Eddie Don
NAXJA Forum User
- Location
- mountain city tn.
All plugs gas fouled tried to pull codes came up all 0's but cel light is on . Ran great before I washed engine . 1998 Xj 4.0 auto WHAT NOW????
old_man
NAXJA Forum User
- Location
- Loveland, Colorado
If you washed the engine, you most likely ruined the throttle position sensor, but first........
Renix engines have an issue that if you wet foul the plugs, they can be a bitch to get started again, even after you fix the original problem. I would by the cheapest set of Champions you can lay your hands on and put them in. I would rinse out the distributor cap with brake cleaner. I would do the same with each of the spark plug boots while you are at it. Double check the firing order for the plugs. It is cast into the intake manifold. If that does not fix it, use a volt meter and diagnose the TPS. You can find plenty of explanations for how to do that on this forum.
Renix engines have an issue that if you wet foul the plugs, they can be a bitch to get started again, even after you fix the original problem. I would by the cheapest set of Champions you can lay your hands on and put them in. I would rinse out the distributor cap with brake cleaner. I would do the same with each of the spark plug boots while you are at it. Double check the firing order for the plugs. It is cast into the intake manifold. If that does not fix it, use a volt meter and diagnose the TPS. You can find plenty of explanations for how to do that on this forum.
Last edited:
Eddie Don
NAXJA Forum User
- Location
- mountain city tn.
http://cdn.cherokeetalk.com/forum/a...26-fouled-plugs-win_20160222_13_23_44_pro.jpg
This is what the plugs look like. They are dry. Not wet.
This is what the plugs look like. They are dry. Not wet.
Last edited:
old_man
NAXJA Forum User
- Location
- Loveland, Colorado
Those look really sooty. Several things can cause that:
1) too much fuel
2) not enough oxygen (air)
3) not enough spark to ignite the fuel completely.
4) not enough compression
I start with the easiest to knock off the list. I would pull the plugs and run a dry/wet compression test. I would then replace the plugs with a fresh set. This will rule out a ton of mechanical possibilities.
I would measure the fuel pressure at the rail.
I would use a voltmeter and verify the TPS is working correctly.
Once you have it running, I would plug on a vacuum gauge. You can have a cat that has shattered and is now clogged.
I would connect a noid light on each cylinder and verify that you are getting pulses to the injectors, not a constant voltage.
I would use a timing light and verify the correct timing. While you are at it, verify the firing order and make sure you have a good fat spark.
I would measure the output voltage of the MAP sensor. On a renix, it is easy to get the plug into the throttle body reversed.
I would measure the resistance across the Air Charge Sensor/ MAT sensor.
My best guess would be a clogged CAT or a bad MAT sensor, followed by a bad MAP sensor, but I would never replace a part without doing some basic troubleshooting.
Just a crazy idea, did you happen to get your air filter wet? I have seen filters collapse and plug the air intake.
.
1) too much fuel
2) not enough oxygen (air)
3) not enough spark to ignite the fuel completely.
4) not enough compression
I start with the easiest to knock off the list. I would pull the plugs and run a dry/wet compression test. I would then replace the plugs with a fresh set. This will rule out a ton of mechanical possibilities.
I would measure the fuel pressure at the rail.
I would use a voltmeter and verify the TPS is working correctly.
Once you have it running, I would plug on a vacuum gauge. You can have a cat that has shattered and is now clogged.
I would connect a noid light on each cylinder and verify that you are getting pulses to the injectors, not a constant voltage.
I would use a timing light and verify the correct timing. While you are at it, verify the firing order and make sure you have a good fat spark.
I would measure the output voltage of the MAP sensor. On a renix, it is easy to get the plug into the throttle body reversed.
I would measure the resistance across the Air Charge Sensor/ MAT sensor.
My best guess would be a clogged CAT or a bad MAT sensor, followed by a bad MAP sensor, but I would never replace a part without doing some basic troubleshooting.
Just a crazy idea, did you happen to get your air filter wet? I have seen filters collapse and plug the air intake.
.
Eddie Don
NAXJA Forum User
- Location
- mountain city tn.
Thank's for all info .