Engine missing badly - throttle body?
Thread Starter
|
Member
Joined: Jul 2004
Posts: 73
Likes: 1
Engine missing badly - throttle body?
My son has a 1999 F150 with the 6 cyl., 4.2 (?), auto. trans. Has recently had a slight 'miss' or hesitation, primarily when the engine is under strain. Check engine light came on.
Went to local auto parts store, they checked the code which indicated either a bad throttle body sensor, throttle body valve or throttle body gasket. The guy working there recommended that we just start with the $2.38 gasket. Also, he recommend some Lucas fuel treatment. He said to pour about 1/2 into the fuel tank, 1/4 into the engine oil and 1/4 directly into a vacuum line while running. He said to then immediately shut off the engine, wait about 10 minutes and restart. Said it would smoke like crazy for about 30 minutes but then we should see results.
This is where it gets good.
Did the above, let it suck the remaining 1/4 bottle directly into a vacuum line. Sure enough, smoked a lot for about 20-30 minutes. However, it now sounds like we are running on about 5 cylinders. Missing, hesitation. Check engine light back on (by the way, we replaced the throttle body gasket, this didn't seem to be the problem).
Any ideas? I've checked all the vacuum lines, they are ok. Whatever the problem, it was definately made worse. I'm thinking O2 sensors in addition to the throttle body thing.
Went to local auto parts store, they checked the code which indicated either a bad throttle body sensor, throttle body valve or throttle body gasket. The guy working there recommended that we just start with the $2.38 gasket. Also, he recommend some Lucas fuel treatment. He said to pour about 1/2 into the fuel tank, 1/4 into the engine oil and 1/4 directly into a vacuum line while running. He said to then immediately shut off the engine, wait about 10 minutes and restart. Said it would smoke like crazy for about 30 minutes but then we should see results.
This is where it gets good.
Did the above, let it suck the remaining 1/4 bottle directly into a vacuum line. Sure enough, smoked a lot for about 20-30 minutes. However, it now sounds like we are running on about 5 cylinders. Missing, hesitation. Check engine light back on (by the way, we replaced the throttle body gasket, this didn't seem to be the problem).
Any ideas? I've checked all the vacuum lines, they are ok. Whatever the problem, it was definately made worse. I'm thinking O2 sensors in addition to the throttle body thing.
Senior Member
Joined: May 2005
Posts: 121
Likes: 0
I am not familiar with Lucas brand but it sounds like it may have ruined the o2 sensors by blosing all that carbon onto them. I have used Seafoam before without damaging any sensors. As for the check engine light, if it threw a code I would be willing to bet that it was the sensor in the first place.
Good luck
Brian
Good luck
Brian
Thread Starter
|
Member
Joined: Jul 2004
Posts: 73
Likes: 1
Sensor
If the O2 sensor(s) are damaged, is it possible to clean them?
Also, regarding the throttle body sensor, I removed it and found lots of carbon fouling (or at least it looked like the inside of an exhaust pipe). There was a piece in the center that was very heavily fouled. Could this be cleaned as well or would I be better off replacing it?
Thanks for the input!
Also, regarding the throttle body sensor, I removed it and found lots of carbon fouling (or at least it looked like the inside of an exhaust pipe). There was a piece in the center that was very heavily fouled. Could this be cleaned as well or would I be better off replacing it?
Thanks for the input!
Senior Member
Joined: Jul 2004
Posts: 3,105
Likes: 4
From: oceanside C.A.
o2 sensors can not be cleaned they must be replaced, i would find out what code is being thrown by the pcm if it sounds like you are missing on a cylender i would change spark plugs to see if that is the problem