I have a '92 F-150 XLT 5.0 5spd Shortbed, and between the idle problems that I can't seem to fix, the 10 miles per galon (average), and the clutch related problems..

I've been having idle problems since I've got this truck, It idles fine but when I hit the gas it takes forever for the RPMs to drop. Some days its better than others. Some days the gas pedal is more sensitve to other days. I took the TB off the other day, and cleaned it completly. It has a NEW TPS and IAC as of 10/04. I never adjusted the TPS, I pull it right ouf of the box and screwd it on, It should be fine right? I did the same with the new IAC.

Other big problem which is causing alot of stress when I drive the truck is the clutch, or something related to the clutch, I'll go to take off, hold the pedal still so the clutch can grab smoothly, and all the sudden, it will just hook as if I was popping the clutch pedal out. Sometimes I even push the pedal back in a little bit just so I don't stall out, YES THE RPMS drop that much upon take off. If I give it a little more gas that usual, and keep it at steady RPM they will acctually go up upon take off..this ALWAYS does this, in 1st gear its the worst (obviouslly) I get some wheel hope half the time.. Its VERY agrivating esp since I've been driving stick vehicles since I've had my licence, Its not like I don't know how to drive stick...Its very embarising when you take your girl or friends out in it, they think I'm new to driving manuel transmission..

AND ON TOP OF THIS! I'm getting 10MPG!! When it first got the truck I would get around 13-15MPG. Now its down to 10, and its beenthis way for weeks. I can't take this much longer, My Mustang is down for awhile, and I'm relying on the truck to get me around but...This clutch is getting worse..

Please give me some advice about these problems Their stressing me out to no end..

Thanks

 

sounds like your cadilac converter could be clogged. as far as the clutch it also sounds like a clutch mis-adjustment

 

hehe cadilac.

There's no adjustment to the clutch, but check under the dash and see if any of the linkage jumps when you release the pedal. As for the engine, I would start with pulling the codes from the computer to see if any error codes are stored. That might point you in the right direction in diagnosing the problem. I don't know if the catalytic converter is plugged, seems to me the rpms would drop faster than normal if it were creating too much backpressure. That truck should definitely be getting more than 10 mpg.

 

my 427 350 dually gets 12mpg...is it a hydraulic clutch? if so , it could have air in the system. check for a vacuum leak on you intake ...

 

Yeah, its unfortinatlly hydraulic...How hard is it to bleed the system??

 

Like bleeding brakes. Pain in da butt. Been awhile since I've done it if someone else can give you a more detailed explination.

 

it is just like bleeding brakes... you'll need 2 people. there should be a bleed port on the slave cyl. at the trans. check to see if the cylinders are leaking, the slave at the bell housing and the master on the firewall. one or the other could be bypassing fluid.

 

Is there a zerk fitting down there on the slave? i got a similar problem, except sometimes mine feels like theres sand in the cylinder until i pump the pedal a few times. I know its probalby time for a bleed but I don't know how to go about doing it.

 

I've heard about pumping the pedal sometimes before lauching, I've tryed this but only makes a very very slight difference, so little that It could just be in my head.. :\

 

I have the same problem with the clutch in the ranger when it is really cold outside. When you let up off the clutch the pedal is slow to return, sounds to me like something is hanging up the slave cylinder or the master cylinder. I wouldn't think it would be air in the lines if the clutch disengages nicely when you push the pedal. Air in the lines would give you a slopply spongy pedal that doesn't disengage the clutch the whole way.

 

If it only happens when it's really cold, it could be water in the line freezing.

 

check the fuse panel under the hood next to the airbox. i had a 15amp that went to the O2 sensor blow on mine(before i bought the truck) and my milage was pretty poor for an inliner. once i replaced the fuse, milage went up.

 

I had the same power problems,and it was my catalytic converter.I thought at first my truck had fuel problems.Like it was not getting enough fuel,boy was i wrong.I have the 460 F-250 1988.Dose your clutch make a clunk when you let off it.Thats the flywheel.Iam going on my second very soon.Any one is welcome to add there comments to this version of truck.I had low idel.It would stall at breaking(tuneup+raise the idel a bit fixed it)