kock sensor 95 f150

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Jul 12, 2009 | 03:46 PM

choochoof150

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From: Mount Vernon

kock sensor 95 f150

Basicly overnight my truck started acting up. It will not idle for nothing. It has a new gt40p motor intake and all new sensors(tps,iac,tfi,mass air). I hooked it up to my buddies snap on scaner and it gives me a knock sensor open circuit and canister purge fault. Has anyone heard of the knock sensor going bad? I will have to order one Mon because no auto parts store has it. Will the canister puge cause it to run bad? Since the motor swap I have put close to 6k mi on it and no trouble.

Jul 12, 2009 | 07:20 PM

DBGrif91

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From: Des Moines

What do you mean "basically overnight"? Did it run fine one day, you went out the next and it ran like crap? Or did it slightly act up one day and get worse the next?

Anyway, try unhooking your battery completely for 12 hours- this essentially "resets" the computer and can help isolate whether or not the problem is actually electrical. I've known scanners to tell you one thing and then after you replace it, that's not the actual problem. Try unhooking the battery then see what happens.

Jul 12, 2009 | 09:12 PM

choochoof150

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From: Mount Vernon

I did undue the battery first, then scaned it after I drove it for a min. The truck was fine but for the last few days the check engine light would flash on for a sec then flash off and stay off far a while. Then sat morning I went out to work on it and it started to run like crap. So I unpluged the battery and let it sit and drove it to my buddies to use his scanner.

Jul 12, 2009 | 09:45 PM

Conanski

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From: Ottawa, Ontario

You erased the computer memory when you disconnected the battery, you're gonna have to stop doing that if you want to find out whats wrong. Are you using a truck computer or mustang computer in it now?

Jul 12, 2009 | 10:36 PM

EPNCSU2006

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From: Concord, NC

Check the wiring to the knock sensor. An open circuit could be something as simple as the sensor being unplugged.

Jul 13, 2009 | 07:54 AM

DBGrif91

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From: Des Moines

Quote:

Originally Posted by Conanski

By clearing the memory the computer can record info on the most immediate problem. A guy can waste a lot of time chasing down problems the scanners show, because you replace one thing and then after that the scanner is just going to show you the next problem. I spent 2 days on a friends car replacing a lot of parts because the scanner would just display one problem after the other, and in the end all my friends car needed was a new o2 sensor.

Jul 13, 2009 | 11:35 AM

choochoof150

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From: Mount Vernon

I checked the connection and wiring and its all fine. I am running the stock 95 f150 computer. The scan tool gave the purge solinoid the first priority and the knock sensor next. I ordered a new knock sensor and purge solinoid from ford garage because they are calibrated to your computer and there are quite a few different ones. I had to give them my calibration number off my door jam so I would get the right one. They will be here Tue.Its just odd that a knock sensor would go bad, but it does have 225k on the knock sensor and purge solinoid. They were the only two sensors and switches that I didn't replace when I rebuilt my truck! We will see how it goes Tue.