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running rich


crackems's Avatar
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02-11-04, 11:57 AM   #1  
crackems
running rich

HAve a 1990 F-150 4.9L. Running rich and will not idle, keeps jumping up and down in rpm's. Not sure what to check.

 
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Desi501's Avatar
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02-11-04, 12:15 PM   #2  
First check for codes and see what data is doing in the computer. If it's running rich, you should have a "check engine" light on. Pull the vacuum hose off of the fuel pressure regulator and see if there is any fuel in it. Check the vacuum hose going to the MAP sensor.

 
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02-11-04, 12:47 PM   #3  
crackems
there is no check engine light on. may sound dumb but where can i find the fuel pressure regulator and the map sensor. have tried to find them in my chilton's manual

 
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02-11-04, 02:34 PM   #4  
Is this a CFI or SEFI Speed Density?
The map sensor is often bundled with thermactor air bypass solenoids on firewall on the passenger car version of this engine
Also on same, the regulator is waaaay backon top, almost in the middle, and the Intake Plenum makes it hard to get to and see
The trucks have a different plenum (SEFI) but it's probably in the same spot
I have also found stored codes with no light so you may want to check that
If applicable (SEFI), you may want to clean out your throttle body and AIC for that wandering idle

 
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02-11-04, 02:56 PM   #5  
Originally posted by crackems
there is no check engine light on. may sound dumb but where can i find the fuel pressure regulator and the map sensor. have tried to find them in my chilton's manual
This is going to be impossible for you to diagnose if you don't have a basic understanding of EECIV and how it works. You may be better in paying someone to diagnose this for you.

 
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02-12-04, 05:02 AM   #6  
don't worry about data...

you can't get data from alot of fords (depends on the year, make and model) it's definately not available on the truck. start with the KOEO self test and see what codes are stored...

 
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