85 Golf races very high RPMS right after starting even with foot off accelerator

[SR Heer]

Yes it has been colder than before in the last month here lately but I live in Houston TX -
so it hasn't been below freezing - My 85 diesel Golf had been started like a week ago and everything ran fine!
I went to start today and it races out of control so I turn off key and it keeps running for a while at very high RPM.
I try again and it really races even with key turned off so I rip the wire going to the injection pump's shutoff solenoid off
and it dies after a bit! It races so fast I am afraid the belt is going to slip or break!
I want to try and start it but have it run or idle normally without it racing so - what would cause this
and what can I possibly do to prevent or fix this?

This is a 1.6NA diesel motor that has run great before - I am pretty sure it is all fuel related rather than oil bypassing the rings and on a "run away" because I have not seen any blue smoke - how can I tell the difference or troubleshoot before its too late?

Any ideas or what to do that might work and bring these RPMs down to earth will be appreciated!
Thanks

[nissannx]

How many rpms is it racing to? Does sound like a runaway especially if you remove power to the pump. What's your oil level at? Any air leaks in the intake system?

[theman53]

You can always use the clutch to kill it with the brake applied. It is weird that it happened all of the sudden, but if it stops when you pull the wire I would say it is pump related. Is anything stuck you can see on the outside?

[libbydiesel]

I try again and it really races even with key turned off so I rip the wire going to the injection pump's shutoff solenoid off
and it dies after a bit!

How long is 'a bit'?  If it dies immediately it is fuel related.  If it runs for any time after power is removed from the stop solenoid, it is most likely oil related.  Check the oil level.  The next step I'd take would be to pull the crank vent hose and try again, this time with a piece of wood ready to block the intake.

[SR Heer]

Nothing is stuck on outside f pump - everything works - except cold start valve is hard or not really able to pull out - I  t disconnected the case vent coming off valve cover and there doesn't seem to be much blow by going into intake. Ok - yes it is mostly fuel related - oil level is up and I have a jumper wire from IP to battery and hand held start switch to crank and it starts but starts to race immediately and when I pull jumper it dies sometimes immediately and other times not - may change out shot off solenoid  - I can control it from running too fast by stopping up air intake inlet with palm of hand so to me it seems that the throttle inside is somehow stuck wide open because I have tried hammering a bit on pump side and top but still starts to race uncontrollably - I thought about having it suck some Diesel Purge into pump and let it sit a for a day - I wonder what could have gotten stuck or frozen or and why? - it ran about two weeks ago before it got colder on us with no problems - could a person vibrate it some how to loosen up what ever might be stuck? Any ideas or suggestions? Thanks!

[vanbcguy]

Be VERY careful using the palm of your hand for that or you might end up with the mother of all hickeys. Exploding diesel can suck air in harder than your skin can resist.

Odd that it keeps going after the wire is pulled even with the crankcase to inlet hose disconnected. That's the usual source for a non fuel runaway.

[SR Heer]

I thought about draining a bit of the oil out - its a bit over the top off mark and then adding a couple of warmed up STP for four cylinders and see if that would drop RPMs - if so then it may be somewhat oil related - it could be combination of fuel and oil - I don't know if injection pumps governor parts or acceleration weights could get stuck in one position or another - don't think its likely - and it ran fine say like three weeks ago before it sort of got cold here - I also thought about putting in a cold weather coolant heater and plug it in to get eng warm and then see if that affects it before I do a diesel purge and let that sit in injection pump overnight - what about the oil rings getting stuck - is there anything I can put into cylinders to soak the rings with that might help them loosen up?

[rodpaslow]

I had an old 1.5 years ago that blew part of the head gasket between cylinder 1 or 2 and the engine was sucking oil from the #2 bolt that feeds the head with oil - it would do like your saying, but there was such a cloud of smoke behind me you couldn't see through it.  I could get it under control by having it in gear and pulling down the engine.  Once it was around idle it would be fine, but as soon as you touched the accel pedal it would start sucking oil and the engine would runnaway.

If it's not oil related, which is what it sounds like, I'd turn down the fuel screw all the way and slowly turn it back up till it idles, and go from there.  It's an NA so you don't have to worry about a turbo causing issues.

[CODE4LS1]

I experienced this problem YEARS ago with a D24T in a '83 Volvo 760.  Only in really cold weather, cold starting will result in immediate "runaway" behavior.  We never figured it out, but by placing the auto trans in gear, we were able to keep it from getting away.  This was on a healthy engine.  No HG leaks and the IP was rebuilt by Bosch back in the day.

[SR Heer]

I am thinking it very well may be a head gasket in that I get pressure immediately in the coolant's expansion bowl - but no water in oil though - ok interesting - thanks for chiming in especially in reference to former HG problem!

[manehfr]

the gasket doesnt only separate oil from water... sometimes its just water to piston or piston to water... or sometimes even just piston to piston... sorry for my english im from portugal by the way... if it has too much oil try draning the extra oil... i saw a friends engine runing away because of extra oil he thought it was missing oil because the oil light was blinking... afterall it was just a wire unpluged... and almost send the piston rings into heaven... hope i helped cheers good luck!

[RabbitJockey]

When my headgasket was bad it only leaked air into the coolant

[manehfr]

exactly... mine too ... and its 2 gaskets with the same simptoms... air in coolant... when i changed the first gasket forgot to tight the head after the 1000km... i didnt forgot the 2nd time thats for sure...