engine revving on its own

[Keith Richards]

This si now about the fourth or fifth time it's happened.The engine just decides to rev high while driving and then stall.Inj.pump was replaced about 30,000 or less miles ago.The truck started to come up on the car infront of me so I popped it in neutral,and then it stalled,and took a minute to fire back up.I hadn;t driven it in a week or so,so I went home and dumped a whole bottle of stanadyne injector cleaner in it,and its been running fine.I definately need new injectors.Is this what is causing this?It is now stalling about once every month or two.I am going to change fuel filter and check that the screws are tight on the pmd this weekend.

[catmandoo]

funny you should mention this,i have been battling a wierd surge for the last year and a half,it did it mainly after i say pull off the freeway i'd pop it in neutral and coast to the stop sign,if i turned right no problem,but left and about the time i go to push the clutch in for second it would surge and throw you back in the seat.i have one corner in particular that it would surge at every time i came to it.well after gelling twice this winter i switched to soydiesel and it has yet to surge at that corner,but at times it seems like the idle is way to high.

[Cowracer]

One cause of uncontrolled engine acceleration is that is starts burning its own crankcase oil as fuel. This can happen if you have shot rings.

Is you oil consumption excessive? Are you generating any blue smoke?

The other thing to look at is the FSD. When my transistor screws loosend up, I would experince intermittant uncommanded engine rev-ups. Usually when going into reverse. Since I tightened the screws and relocated the FSD to a cooler, I have not had one incedent.

Tim

[catmandoo]

as for me i have a 92 and it uses maybe 1/4 of a quart in 2500 miles.it almost acts like the cold adv is coming on,i'm gonna try unhooking the wire tomorrow and see what happens.

[charliepeterson]

A classic sign of a PMD failing is for the engine to have the cruise control on when it's not on. The first step is to look for any engine codes. If none look very hard at the pump driver. One other test is in neutral, slowly bring the RPM's up to about 1500-2000 and hold the accelerator still. If the RPM's climb to the governed speed by them self, the driver is toast.

Other signs of failure are the stalling like you turned the key off. If stuck on the road pour tap water on the PMD to get home. Unfortunately when this thing goes South it will never leave a code behind.

[Keith Richards]

Thanks.I guess its about time,its been over two years of no inj. pump or pmd problems.I certainly hope its not burning its crankcase oil,I dont have any blue smoke while driving,maybe a little blue gray on start-up,just a puff.Ive been driving it all week with no incidences.I will be looking into a new pmd or fsd(whatever its called)in the next few weeks.

[MTTwister]

Keith - PMD when it's mounted on the pump, FSD when it's remotely mounted. If you can get it off the pump, try tightening the Transistor nuts. finger tight + 1/8 of a turn. Also best have a new replacement handy - just in case. Spare parts seem to take up a lot of room in the bed.. [img]smile.gif[/img]