lean 302
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lean 302
hey all sorry if this has been asked in the past. i ran a search with no success but i have a 1990 f150 with a 302 that pings pretty bad and i ran the computer codes i got a 31 in continuous memory wich my book doesnt show and i got a koer code of 41 wich indicates a lean condition. can anyone point me out in the right direction where to start with this thing. the rear tank fuel pump has a bad check valve so i thought that might cause it but when im using the rear tank it runs the same. also i did a fuel pressure test. and it passed the only thing that failed was the static pressure test which makes it a little tough to start. if it was a vacuum (sp) leak wouldnt it idle poorly? anyways this post is getting too long... well thanks in advance for any help. dennis
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lean 302
A few things to start with to check. Make sure these things are in good shape.
1. O2 sensor
2. Map sensor
3. Make sure the fuel injectors are clean.
4. Throttle position sensor (very rare, but can be reading that the throttle is in the wrong posistion causing it to cut out on gas and give you a lean mixture)
5. Fuel Filter (take it off and Blow through it, if you have any resistance, then replace the filter)
Also, make sure you clear you codes and run the engine again. Sometimes it will be a fluke that causes that reading, but the computer stores it and continues to run the fix.
1. O2 sensor
2. Map sensor
3. Make sure the fuel injectors are clean.
4. Throttle position sensor (very rare, but can be reading that the throttle is in the wrong posistion causing it to cut out on gas and give you a lean mixture)
5. Fuel Filter (take it off and Blow through it, if you have any resistance, then replace the filter)
Also, make sure you clear you codes and run the engine again. Sometimes it will be a fluke that causes that reading, but the computer stores it and continues to run the fix.
Laughing Gas
Joined: Mar 2003
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From: Colorado, U.S.A!
lean 302
I think tracman's on the right trac.
You're right about the possibility of a vacuum leak, dennisr, it probability would affect idle. It probably wouldn't cause pinging on a MAP engine, as far as I know...
You're right about the possibility of a vacuum leak, dennisr, it probability would affect idle. It probably wouldn't cause pinging on a MAP engine, as far as I know...
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lean 302
thanks for the excellent responses i finally got a chance to check it out again this afternoon the first thing i checked was the map sensor chiltons says with no vacumm applied and using a 6cyl. tach you should get about 300 some odd rpms and i get about 800. so my dad is bringing a map sensor home tonight i will post the results. ps on a side note while fiddling i pulled one of the smaller vacumm hoses off while the engine was running and idle was not affected. so i suppose that a smaller vacumm leak doesnt always affect idle. anyways thanks for all the help.
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lean 302
ok now i reread the manual its actually haynes. and when pulling codes it says to run the thing to let it warm up before doing koer test so i reset the codes and let it warm up this time doing the keor test. now i get two codes a code 12 and 45. in the book code 12 is cannot control high idle and 45 is not listed does anyone have any info on code 45? thanks again
Laughing Gas
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From: Colorado, U.S.A!
lean 302
According to "Ford Fuel Injection & Electronic Engine Control" byCharles O. Probst, an engine running code 45 means "Secondary Air Injection upstream during Self-Test". A continuous memory code 45 means "DIS coil pack 3 circuit failure or Coil 1 primary circuit failure".
I guess that first one applies to you.
I have no idea what that means... Good luck!
I guess that first one applies to you.
I have no idea what that means... Good luck!
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lean 302
Sounds like your diverter valve is not functioning. That vacuum line that you pulled of may have been the control for the diverter valve. Get that valve working and then rerun the EEC tests.
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lean 302
ok latest breaking update i cant remember the exact name of it but the vacuum solenoid that controls the egr valve is not functioning properly and the evr sensor is out of specs according to the manual. im pretty sure the solenoid/valve is bad because i removed and plugged the supply vacuum line for it and the truck runs better. im not sure about the sensor because this manual was wrong as far as specs on the map sensor so i will be ohming out a new evr sensor before i replace it. and finally i redid the koer test several times today without that code 45 so i will have to keep an eye on it. maybe the vacuum leak from the egr solenoid was preventing it from functioning anyways i will keep everyone posted with updates. BTW what an excellent site ive used it before to get tune up specs for my 64 f100 keep up the great work. - dennis