runs bad
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Fleet Mechanic
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From: va
runs bad
87 ford f150 runs bad. Tune up is done. Whats the best order to check sensors? IAC,o2,TPS,MAP, then? The plug in port is damage so i cant check for codes.<!-- / message -->
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From: Still under the hood in O
Okay, first some details.
When does it run bad? (idle/under load/cruise/hot/cold/ all the above?)
And exactly what does it do?
Black smoke? backfire either through intake or exhaust?
Does it ever smooth out (even a little)?
What did you replace on the tuneup?
When does it run bad? (idle/under load/cruise/hot/cold/ all the above?)
And exactly what does it do?
Black smoke? backfire either through intake or exhaust?
Does it ever smooth out (even a little)?
What did you replace on the tuneup?
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Fleet Mechanic
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From: va
Originally Posted by 90f150moneypit
Okay, first some details.
When does it run bad? (idle/under load/cruise/hot/cold/ all the above?)
And exactly what does it do?
Black smoke? backfire either through intake or exhaust?
Does it ever smooth out (even a little)?
What did you replace on the tuneup?
When does it run bad? (idle/under load/cruise/hot/cold/ all the above?)
And exactly what does it do?
Black smoke? backfire either through intake or exhaust?
Does it ever smooth out (even a little)?
What did you replace on the tuneup?
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From: Still under the hood in O
Two things to try since giving it gas smooths it out.
Have someone rev the motor while you hold your hand in front of tailpipe to see if black soot comes out. This will tell you if it's getting too much gas. If it does spit out soot, replace the fuel pressure regulator. It may be weak.
Pull the IAC and throttle body. Use throttle body safe cleaner to clean both of them out real good, use a toothbrush if needed. Make sure to remove the sensor/motor from the IAC before spraying it (two screws).
Also while the EGR is disconnected make sure it isn't plugged.
Have someone rev the motor while you hold your hand in front of tailpipe to see if black soot comes out. This will tell you if it's getting too much gas. If it does spit out soot, replace the fuel pressure regulator. It may be weak.
Pull the IAC and throttle body. Use throttle body safe cleaner to clean both of them out real good, use a toothbrush if needed. Make sure to remove the sensor/motor from the IAC before spraying it (two screws).
Also while the EGR is disconnected make sure it isn't plugged.
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From: Still under the hood in O
Did you check as I described??
(your not looking for raw fuel - by products)
Cleaning the system does NOTHING for a bad FPR.
(your not looking for raw fuel - by products)
Cleaning the system does NOTHING for a bad FPR.
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Fleet Mechanic
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From: va
I can keep it running with starting fluid.
While its running rough for about 2 mins. if i spray starting fluid in the intake of the throddle body It will run high idal but runs smooth. It will stall as soon as the starting fluid dries out. I can restart it, will run bad again for about 3 mins. Nothing at all in the exhaust dry. Thanks
Last edited by mike L; Sep 23, 2004 at 01:54 PM.
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Fleet Mechanic
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From: va
Update, cleaned out the IAC and it now stays running for 10 mins at a time.
Exhaust is clean. But it took about 20 mins before it would run after cleaning the IAC??? It will run for 10 mins. at a time and then it stalls. Still runs a little rough though. I need to spray some starting fluid before it will start each time, even with both fuel tanks. Any ideas? Thanks
Exhaust is clean. But it took about 20 mins before it would run after cleaning the IAC??? It will run for 10 mins. at a time and then it stalls. Still runs a little rough though. I need to spray some starting fluid before it will start each time, even with both fuel tanks. Any ideas? Thanks
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From: Still under the hood in O
Pull the throttle body off and clean it thoroughly too.
Since cleaning the IAC allowed it to run for a longer period but still acting up, I would guess it's no good. More often than not if cleaning the IAC results in positive results it's time to replace it. Even if it were to completely fix the problem, a short time later they fail anyway but at least you would know that the problem is from the IAC.
They aren't cheap but I would spring for it if it were me, but I would also get that TB off and cleaned good (paying close attention to the air passage and EGR port).
Since cleaning the IAC allowed it to run for a longer period but still acting up, I would guess it's no good. More often than not if cleaning the IAC results in positive results it's time to replace it. Even if it were to completely fix the problem, a short time later they fail anyway but at least you would know that the problem is from the IAC.
They aren't cheap but I would spring for it if it were me, but I would also get that TB off and cleaned good (paying close attention to the air passage and EGR port).
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From: va
Thanks, will do. I have a 1" tube that runs along the straight six head. It looks like its metal and moldeled to the head. It has six 1/4" tubes coming straight up from the side of the head. Right across from the spark plugs. Right at the head it has a small fuel leak, still wet after a few hours. It has a 1" size rubber hose at each end and the other end that runs back about the injectors is hollow. What it this part, why is there a small fuel leak, must be coming up from the head?
What are some thing that would make my truck run rich? Cleaned the plugs and the after 10 minutes of running, it had had black dry sooty ....? carbon? on all of them. Thanks again
What are some thing that would make my truck run rich? Cleaned the plugs and the after 10 minutes of running, it had had black dry sooty ....? carbon? on all of them. Thanks again
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Fleet Mechanic
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From: va
Originally Posted by 90f150moneypit
Did you check as I described??
(your not looking for raw fuel - by products)
Cleaning the system does NOTHING for a bad FPR.
(your not looking for raw fuel - by products)
Cleaning the system does NOTHING for a bad FPR.
Can the fuel regulater be running high which is causing the fuel to stop running? Because it stalls after ten minutes of idling. My guess is its running with low pressure and it running rich is a bad sensor???
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Fleet Mechanic
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From: va
Originally Posted by 90f150moneypit
Check for a vacuum leak using the starting fluid.
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From: Still under the hood in O
Originally Posted by mike L
I held a white rag across the exhaust and it came out black but after 10 minutes of running it was clean nothing on white rag.
Can the fuel regulater be running high which is causing the fuel to stop running? Because it stalls after ten minutes of idling. My guess is its running with low pressure and it running rich is a bad sensor???
Can the fuel regulater be running high which is causing the fuel to stop running? Because it stalls after ten minutes of idling. My guess is its running with low pressure and it running rich is a bad sensor???
As far as the fuel leak - find where it's coming from and fix it. Sorry, I don't know anything on the 4.9, and my 5.0 doesn't have that pipe so I don't know what that is.