Rough idle-'94 F-150 4.9L
#1
Rough idle-'94 F-150 4.9L
Hi guys. My engine has been idling a little rough lately. Plugs, wires cap, rotor, fuel/air filter are less than a year old. I typically stay on top of the routine stuff. The truck accelerates great. I know the timing is good because I had to set it after replacing the pickup coil in the distributor. I ran some fuel injection cleaner through it, but it didn't seem to make a difference. This has been going on for more than a few tanks of gas. It is the same on both tanks.
I got to looking at the IAC. I need to measure the reistance on it as per the manual. I unplugged it while the engine was running and it did get worse. The idle started doing more of a rythmic surging up then down, then up then down. With it plugged in, it stablizes but is a little rough.
When I say rough, looking at the engine it seems to be perfectly smooth. The engine isn't bouncing. But, I can feel it sitting in the driver's seat.
Ideas anyone?
I got to looking at the IAC. I need to measure the reistance on it as per the manual. I unplugged it while the engine was running and it did get worse. The idle started doing more of a rythmic surging up then down, then up then down. With it plugged in, it stablizes but is a little rough.
When I say rough, looking at the engine it seems to be perfectly smooth. The engine isn't bouncing. But, I can feel it sitting in the driver's seat.
Ideas anyone?
#2
Your seat has Mexican Jumping Beans in the cushion.
Serious note, can you feel it in the steering wheel / breaks / accelerator?
#5
#6
Well, I removed the TB and cleaned it. Looks like the TB gasket might have failed. It is amazing how dirty a TB can get when only air goes through it. Also, the two vacuum lines that connect to the TB were comparable to old marshmellows. I replaced them as well.
Problem is resolved. It idles smooth now.
Thanks for all the help!!!
Problem is resolved. It idles smooth now.
Thanks for all the help!!!
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