hi, i have a 95 f150 with a 300ci efi inline 6 with an auto tranny

whenever its cold the speedometer will stay on the needle stopper and not on 0! the truck takes a really long time to heat up and when the temperature gauge finally gets to normal the speedometer will still stick at the stopper until i give the top of my dash a few hits...but sometimes that doesnt even work! On top of that my engine will turn off when my truck stops, but only when my speedometer is sticking or twitching back and forth! before it wasnt stalling and the gauge just stayed at zero tell i drive a couple miles and then it would kick on! now it stalls once i put it in gear and stop again! most of the time when i put it in gear i can leave my foot on the brake and it will stay running and sometimes it will die without even engaging the wheels! it only dies when the truck is at a stop! I replaced my tps sensor thinking that was the stalling problem but that didnt do anything! i took my idle air control off and shot it real good with throttle body cleaner and let it soak in it, but still that didnt fix the problem! the next thing im going to try is just replacing the idle air sensor and see what that does but i dont understand why it only stalls when the speedometer is acting up?!?

 

Have you ever cleaned the throttle body butterfly valve?

 

ya i cleaned the whole throttle body and the problem still persists!

 

-1995 F-150 4.9L EFI, 5spd manual, 2wd-

My 95 is doing the same thing but she'll also stall when I start to let the clutch out.

I've even got the crazy speedometer- fluctuates very quickly +/- 20 mph of how fast I'm going.

I cleaned all the electrical connections associated with the throttle body and the connector to the transmission for the speedometer; but it did not fix the problem.

I was told that it was a grounding issue, but mine are okay, hence grounding does not seem to be the problem with mine.
It is a very frustrating problem.

I'll be paying attention and good luck.

EDIT: Also, mine has progressed and now behaves this way even after the engine reaches normal operating temperature.
-Ken

 

ya same here, i live in texas so the weather right now isnt that cold and even when its 80 degrees it doesnt want to heat up on the gauge!

recently the blinkers and hazard lights dont work so now im off to the parts store to get a new flasher fuse! maybe that will help but im still wondering whats making it die!

im also considering the fuel injection box which has control of mostly everything or the voltage regulator or alternater!

 

there is a break on off switch that can affect idle also a power steering switch that can stop the engine altogather if you use the power steering at idle or close to it along with the normal stuff that will affect drivability it has nothing to do with the speedometer that's a seprate issue do you know if there are any check engine codes has the light flashed at all even for a second while runing

 

no check engine lights with mine.

f-150m- the blinkers & hazard lights could be the multi-function switch in the steering column.

-Ken

 

well F series trucks where kinda funny about their diagnostics those sensors didn't light up the check engine light last time I scaned one it was on there after a different repair and they didn't want to mess with it and no light just somthing usually not looked at

 

Why on earth does this sound to me like a bad vacuum line or one that isn't connected?

Can you get a vacuum guage and test it?

 

well ya but after being under the hood with what was done I figured it would have been found but maybe not could be

 

I've checked mine; but it's worth another look.

f-150m: any progress on yours?

-Ken

 

I rechecked my vacuum lines- all okay
Checked PCV valve- it's fine
Replaced EGR valve- no change

I'm going to do a tune up on Friday, just for laughs, and maybe replace the idle air control.

-Ken

 

Tune-up is done and the problem persists.

-Ken

 

With the tune up, my truck runs smoother, and so I detected a slight skip from just off idle, to about half throttle. I have no tachometer, so I cannot give a more accurate rpm range.

On a side note which just occurred to me: apologies for the thread hi-jack.

-Ken

 

Run some Berrymans B-12 through the fuel system at double strength. If there's a fuel blockage or rsetriction it will clear it.

DO NOT EVER DO THIS TO A DIESEL