Runaway engine!

[Gizmo 007]

OK fellers, need your help again. Got a '93 dodge with a wicked pump problem.



After starting the truck, it idles like a dream. If i just touch the throttle, it runs away... After restarting, it will idle again, until I touch the throttle. It has the old mechanical rotary pump. Have inspected the boost diaphragm, and found that the pin that rides on the diaphragm shaft (part of the throttle linkage) shoots out when i touch the throttle, but won't retract on it's own.



Does anyone know of anything to look for inside of these pumps that would cause this? could the governor spring be broken and cause this? The problem started instantly while driving, like something inside the pump broke.



Anything is helpful! Thanks!

 

[Philip]

Sounds like someone cranked the fuel screw in to far.



It is located on the back side of the pump above the lines running to the injectors. If the cap is gone off of it. Back it out a couple of turns and see if that stops the runaway condition.

 

[phillips5]

philip is right when the screw is in too far the engine will take off and fly.

 

[Gizmo 007]

Thanks guys... I'll try that. I'll report back in the morning

 

[BushWakr - RIP]

Pull the inlet air tube off the front of the turbo and have a buddy stand there with a board or something to stick over the turbo inlet in case the "key off" option fails to precipitate the desired results... . it happens... .



BTW, is this a new problem? Have you made any tweaks that may have started this? If not, you may have another problem with the pump.

While it is not too common for the 93 model year to have this existing internal problem there was a recall of certain VIN trucks that could experience this, and they were called back for pump replacement.



Bob.

 

[farmerzo]

My truck likes to run away if you rev it in park or N, doesn't usually do it in gear. Its not as bad now that the screw is backed out some (transmission is gone). Is there a way to solve this without backing the fuel screw out? The stock pump never did this with the screw in way to far, I now have a pump from scheidts that is awesome, but it likes to runaway and lopes at low rpms in gear. TIF alonzo

 

[Philip]

Is there a way to solve this without backing the fuel screw out?

I do not know.



I was wondering who was driving the Red/silver truck at the Indy Dyno meet Sat. I didn't get to meet you. I was driving the black 1st gen dually parked to the south of you in the west side row.

 

[farmerzo]

I didn't get to go to the dyno day in Indy, I had a class field trip that day. I might of went through Indy but can't remember.

 

[Gizmo 007]

BushWakr, we haven't jacked with the pump... yet .

BTW, Nice post on the gov. spring! That's great work!



well, the fuel screw didn't solve the problem... Going to tear into the pump and check out the gov. spring assembly.