1994 f150 4x4 5.0 manual.. My speedometer quit about a week ago for some reason and my ABS light is on and now when im driving down the road my truck will randomly cut out and back in just randomly all the time. Anyone know why?

 

ABS and spedo use the same sensor and a module to split the signal, the engine problem is probably unrelated. Check your grounds. All of them. Also take a look at all of the connectors in the ignition system, and pull codes. My coil connector plug was fouled a while ago, did the same thing, $11 at napa for a new one.
-Mike

 

Does the motor die at any throttle position, and restarts itself from being in gear?

 

mainly like 45 mph and up.

 

Does it happen while it's not moving? Should be pretty easy to narrow down if it does.

The speedo/ABS light could either be the wiring to the VSS on the rear axle or the PSOM inside the dash cluster. Probably the PSOM but with the other problems you have, it could be wiring.

 

no it only seems to do it when im driving down the road at a pretty decent rate.

 

One thing I try to do when an engine is quitting or missing real bad, is figure out if it's an ignition problem or a fuel delivery problem. If you have a tach, or if you can rig one up so you can SAFELY see it while you are driving, it will tell you which it is. If the problem is ignition, the tach will drop like a rock and then jump back when the engine starts back up. If it's fuel related, the tach will drop slowly as the engine speed drops off. Hope this helps.

 

its literally split second when it dies and then comes back, the tach isnt even fast enough to catch it.

 

I had this happen not long ago, steady throttle, around 35 mph. Would happen once or twice during trips around town running errands. I cannot say with certainty what cured it, because I did alot of work on this truck the last couple of months. I would guess that of all the items that I replaced, that one of these four, were most likely the cause of that particular problem, listed in high probability culprit order: installed a new distributor & shined up block contact area to insure a good ground. Re-manufactured computer, new coil, new ignition switch.

 

where is the abs speed sensor located? and i have a new coil, dist cap, rotor, plugs, wires fuel filter and air filter already.

 

On the top-front-drivers side of the rear diff. If you haven't already, pick up a Haynes, its faster then waiting for responses.
-Mike

 

ok thank you