89 351 emissions failed.. no codes
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89 351 emissions failed.. no codes
I have an 89 F250 with a 351 AT 4WD. Just failed emissons miserably. Hydro Carbons and carbon monixed were WAY too high. Also, it seems to be running very rich, and the MPG are terrible. I pulled the codes, but they didn't reveal anything. Also, it is dualed out with no cat converters, but it's been that way for a couple of years. Just recently, it started running like crap and using a lot of gas. I need to get it thru inspection, but more importantly, I need to get it running better. Any/all comments are appreciated. Thanks!!
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Joined: Jul 2005
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From: Calgary, Alberta.
I used to have poor gas milage with my 88 F250, 460cid, and it was always black in the tailpipe. I changed out the O2 sensor (It was completely broken for about 2 years) and replaced the Coil/spark plug wires, and the milage almost doubled. The O2 sensor does degrade over time, so that's where I'd suggest starting.
Good luck.
Good luck.
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Joined: Jun 2004
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From: Central NY
Am I to understand that a 351 with no cats previously passed emissions testing?
I find that remarkable.
Running rich will destroy your o2 sensor I beleive.
Check your fuel pressures. They should be about 40 primed, and 32 running. Pull the vacuum line off the fuel pressure regulator and it should jump up to 40'ish again. There should be no gas present in the disconnected vacuum line or the port it connects to. If you see any, replace the FPR.
What codes did you pull? Sometimes a code can be caused by other problems so Its good to know what you've got even if you thnk its trivial.
I'd replace that and add hi-flow cat(s). They are about $60 on ebay from what I've seen on other posts.
Let us know what you find,
Popa Tim
I find that remarkable.
Running rich will destroy your o2 sensor I beleive.
Check your fuel pressures. They should be about 40 primed, and 32 running. Pull the vacuum line off the fuel pressure regulator and it should jump up to 40'ish again. There should be no gas present in the disconnected vacuum line or the port it connects to. If you see any, replace the FPR.
What codes did you pull? Sometimes a code can be caused by other problems so Its good to know what you've got even if you thnk its trivial.
I'd replace that and add hi-flow cat(s). They are about $60 on ebay from what I've seen on other posts.
Let us know what you find,
Popa Tim
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I bought this truck from North Carolina, which I assume doesn't have as tough emissions standards as Maryland. It passed Md safety inspection, so I got tags for it, but now I can't get it thru the emissions test. I will put a converter on it, but I know that is not going to help with the problem of it dumping fuel out the tailpipe. I need to fix that before putting a converter on. Any comments are appreciated.
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