Diesel Stumbling

I have a 92 Golf Diesel 1.6L that likes to stumble, or miss, at high
rpms. I also think that the power is lessened too but this is hard to
conclusively prove. But when the cold start is pulled out the car will
run fine.
I have checked the timing belt, replaced the injectors and there is no
air in the fuel lines. If anyone has some ideas let me know?
Also does anyone know if driving all the time with the cold start
pulled out is hard on MPG or anything else? Cause I am getting to that
point on long drives or hills.
Thanks

Its probably pump rebuild time by the sounds of it.

You may want to change fuel filter as a cheap check. Mine appeared okay
in my '81 Rabbit but lost power up long hills - changing the filter
helped.

Mike

You said you checked your timing belt, but did you check the timing. Is it
in the exact range. If you can , and feel like fooling around. put it near
the top end of the range. As close as possible, but don't go over. Also how
many miles is on the engine. Do you think it is tired . You wont hurt
anything driving with the cold start out. Timing advance doesn't affect the
mileage on Vw diesels Theoretically. it may get better, by a super small
amount. but not worse if your timing is correct. I leave my advance lever
out most of the time because my VW is worn and tired and it runs better
advanced.
"92Golf" > wrote in message
oups.com...
>I have a 92 Golf Diesel 1.6L that likes to stumble, or miss, at high
> rpms. I also think that the power is lessened too but this is hard to
> conclusively prove. But when the cold start is pulled out the car will
> run fine.
> I have checked the timing belt, replaced the injectors and there is no
> air in the fuel lines. If anyone has some ideas let me know?
> Also does anyone know if driving all the time with the cold start
> pulled out is hard on MPG or anything else? Cause I am getting to that
> point on long drives or hills.
> Thanks
>

What none2u said.

I also agree with Mike L, a new fuel filter is a cheap and easy
troubleshooting step.

How many miles do you have on the timing belt and tensioner?

Yea it, does sound like its losing fuel at high rpms. The filter is an
excellent idea. I just offered another thing to cheaply check. My thoughts
on the timing were if the engines marginal, or has less compression on a
cylinder. and the timings off, maybe every cylinder isn't firing everytime
when he's at high rpms. And by advancing the timing as far as possible, its
got a better chance to fire the fuel. This may be why the advance lever
helps. I,d try everything before pulling a pump.
> wrote in message
ups.com...
> What none2u said.
>
> I also agree with Mike L, a new fuel filter is a cheap and easy
> troubleshooting step.
>
> How many miles do you have on the timing belt and tensioner?
>

Thanks for all the responses. The timing belt is new but the tensioner
I have never replaced. The tensioner is also pretty well maxed out to
get close to the right tension. I have only owned the car for a year
(20,000km) and the motor is up there at 450,000km. I have alot of
faith in VW diesels though but it could be many things at this point.
Is there anyway to test the injection pump? The fuel filter was also
changed when I got the car. I am going to try to find a diesel
compression tester and see what I can get. I don't have the indicator
to check the exact timing on the pump but I am looking for one as well.
Thanks again

I am a pain in the ass, but one thing I am is the king of getting piece of
crap VW diesels to run without paying too much. They are the bomb. I have
faith too. I regularly drive 100 miles to visit my brother, at 70 mph, in an
85 golf diesel, with 200,000 mi. that's been overspeeded twice, run low on
oil, and the trans whirrs, and makes people back off from the oil burning.
Instead of taking my 2005 Toyota Echo. There's not much you can check on the
pump without the appropriate Bosch proprietary rights protected Test
equipment and books. There's plenty of high quality used pumps available.
You need to get the pump timing up at the upper limit. At least check it. If
its out of range, put it in. If its low that may be your problem. If its in
, put it at the top. Do not go over. Or you will have cold starting issues
below 20 degrees. You need to know your timings nuts on. I mean pump, cam
and crank locked down. plenty of people change belts and don't set it due to
lack of tools. Or you're wasting your time. You could check your compression
FYI, maybe a cylinders low. or if you're thinking of rebuilding the motor.
450,000km should have compression down. Then what are you going to do. If
the timings belts new, and the tensioner isn't wobbling around or feels
loose , almost maxed out tensioner belt is ok. you've done the filters ,
injectors, belt, timings good, compression is good. if the problem still
exists, and you don't want to drive around with the advance lever out. Then
the pump. then the engine. Good luck.
"92Golf" > wrote in message
oups.com...
> Thanks for all the responses. The timing belt is new but the tensioner
> I have never replaced. The tensioner is also pretty well maxed out to
> get close to the right tension. I have only owned the car for a year
> (20,000km) and the motor is up there at 450,000km. I have alot of
> faith in VW diesels though but it could be many things at this point.
> Is there anyway to test the injection pump? The fuel filter was also
> changed when I got the car. I am going to try to find a diesel
> compression tester and see what I can get. I don't have the indicator
> to check the exact timing on the pump but I am looking for one as well.
> Thanks again
>

Thanks for the thoughts. It is good to hear someone else's ideas on
it. I am going to get checking the timing on the pump then follow your
advice to the pump then motor. I had the idea but wanted to pass it by
you guys first.

Something you may be able to replace yourself is the shaft seal. However
that usually causes the pump to loose prime when sitting resulting in a slow
start. If you think it's the pump something I've done several times with
very good results is to add a inexpensive generic gasoline electric fuel
pump just before going into the filter. The injector pump returns any excess
fuel to the tank so there's no problems with too much. I just wire them up
to the stop solenoid. It'll run like new because it's getting the proper
amount of fuel.

Joe Romas

"92Golf" > wrote in message
oups.com...
>I have a 92 Golf Diesel 1.6L that likes to stumble, or miss, at high
> rpms. I also think that the power is lessened too but this is hard to
> conclusively prove. But when the cold start is pulled out the car will
> run fine.
> I have checked the timing belt, replaced the injectors and there is no
> air in the fuel lines. If anyone has some ideas let me know?
> Also does anyone know if driving all the time with the cold start
> pulled out is hard on MPG or anything else? Cause I am getting to that
> point on long drives or hills.
> Thanks
>