Can't figure it out

Technical questions and answers concerning all models of VW diesel vehicles.

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Hans
Glow Plug
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Location: Park Rapids, MN
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Can't figure it out

Post by Hans »

Hi everyone,
I have been looking around this forum for a while now and have found a ton of great info, but it has come time for me to ask some questions.

I am having starting problems. I have read the hard starting sticky, I've got good glow plugs, no air in the lines, good injectors, and a new battery. Usually the car starts just fine, although it usually takes some amount of cranking, but every now and then, especially when it's really cold, it just doesn't want to start. I started to think that the starter was bad so last week I took it apart and cleaned all the black gunk out of it. After putting it back it definitely feels stronger. It is really cold where I am at 0-10 F but I do have a block heater, which works, and that hasn't been helping me either. The thing I haven't checked is compression as I don't have a tester, but I was under the impression that even with bad compression the thing should start up after being plugged in for an hour or two?

I would greatly appreciate any suggestions. One other thing, when I am cranking it I get a lot of white smoke(vaporized fuel?) coming out of the exhaust and air intake manifold, I would think that this would imply the engine is getting plenty of fuel, yet it just won't fire.

Thanks
Jon
83 Rabbit 1.6L NA
202,000 miles
VWCaddy
Missing Linkz
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Post by VWCaddy »

How did you test the glow plugs?
- http://www.4crawler.com/Diesel/CheapTri ... lugTesting

Might also be low compression and/or high altitude starting. I used to have those problems with my old 1.6D at 6000'+.
'82 VW Caddy, 1.9D engine, FN tranny w/ Quaife, Missing LinkZ shift linkage
jogl8
Glow Plug
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Location: SW Ontario Canada

Post by jogl8 »

With 200,000 miles your compression really is the next logical thing to check. $25.00 to rent here is not a bad deal. For $50 you could probably get a shop to do it for you.

JP.
Many Diesels in my family.
Vincent Waldon
Turbo Charger
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Post by Vincent Waldon »

And test the compression with the engine stone cold... it will do you no good from a cold starting perspective to have great warm compression but lousy compression when the engine has been sitting overnight !!!
Vince

Edmonton, Alberta, Canada
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Gone but not forgotten: 1969/1971 Beetles, 1969/1974 Westies, 1979 Rabbit, 1986 TD Jetta, 1992 gas Jetta, 1994 TD Jetta

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stopping
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Post by stopping »

there seems to big much white smoke on this site..... so much that.... it may be hard to find answers to searches and queries. Is it worth having a white smoke/ blue smoke sticky?

Hans... Does your cold start work well and timing right?
I think you should check for good fuel flow from the tank, blocked filter and I would check compression too but after eliminating everything else.
Hans
Glow Plug
Posts: 19
Joined: Tue Jan 09, 2007 7:18 pm
Location: Park Rapids, MN
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Post by Hans »

I tested the glow plugs first using a battery tester, then later I visually checked them when I replaced the injectors.

I guess the compression check really is in order, it just seems that if bad compression is the big issue that I should have poor cold starting all of the time?
83 Rabbit 1.6L NA
202,000 miles
stopping
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Location: Montreal, QC, and StJohn's, Nfld, Canada

Post by stopping »

well it should also start when it's warmed buy the heater... no?
Hans
Glow Plug
Posts: 19
Joined: Tue Jan 09, 2007 7:18 pm
Location: Park Rapids, MN
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Post by Hans »

Oh yeah, my cold start does work well, and I believe that the timing is pretty good, when I push the cold start in when it is cold the engine misses.

The filter is something that I have been considering. I did replace it within the last month, however it is just a filter that I got from the auto store, not OEM.

Just recently I was having problems with air in my lines which I suspected was due to a leak coming out of the cold start seal. So I replaced the seal which cured that problem right away. Although I still notice minuscule air bubbles traveling from the filter to pump when the car is running. Not sure what to think about that? Fuel filter? Some blockage in the lines maybe?

I can't imagine little bubbles like I have could affect starting?
83 Rabbit 1.6L NA
202,000 miles
Hans
Glow Plug
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Joined: Tue Jan 09, 2007 7:18 pm
Location: Park Rapids, MN
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Post by Hans »

And no, plugging the car in didn't help much.
83 Rabbit 1.6L NA
202,000 miles
coke

Post by coke »

Are you giving the car some throttle while cranking? Say, 10F or lower, half way to the floor?
Hans
Glow Plug
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Location: Park Rapids, MN
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Post by Hans »

I usually don't give it a lot of throttle until it starts firing. I have always been a little weary of giving it a lot of throttle because I don't want to flood the thing...maybe this isn't a concern? Also I figure that it is getting plenty of fuel because vaporized fuel comes billowing out like crazy.
83 Rabbit 1.6L NA
202,000 miles
tawney
Turbo Charger
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Location: Watkinsville, GA

Post by tawney »

Low compression is undoubtedly a contributing factor, but I'll bet there are some other issues also. You mentioned cleaning the starter; did you apply grease to the bearings, etc? Cranking RPM makes such a big difference, especially if compression is low. You might see how easily it starts when you roll start it; the faster rotation will usually start it right up.
One fairly easy thing to check is the camshaft timing; it's odd you're getting smoke out the intake. Finally check the injection pump timing, but you'll need a dial indicator.
Fatmobile
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hard start

Post by Fatmobile »

Have you checked the valve clearances?
I heard they can cause a hard start.
libbybapa
Turbo Charger
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Post by libbybapa »

Yup, Check timing AND ANY bubbles in the line can be your hard starting problem. It indicates that either your fuel filter (or line to tank) is plugged/restricted or that you have a leak. If there is even a slight leak, it can cause the system to lose a bit of fuel and take a bit of cranking to start.

Andrew
Hans
Glow Plug
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Joined: Tue Jan 09, 2007 7:18 pm
Location: Park Rapids, MN
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Post by Hans »

Hey thanks for all the feedback.

I really don't think that my cam timing is off. When I replaced the timing belt last I had the cam nicely locked in place with the slot parallel. But I am definitely getting vapor coming out of the intake. Also I have check the valve clearances and everything was within spec.

Today I dug into the fuel tank, removing the sender unit. My intention was to check out the pickup screen and see if it was clogged, but turns out mine is not there? I drained as much fuel as possible and looked all around inside the tank but there is no sign of a loose screen. My guess is it was previously clogged and just removed. I did blow air back into the tank and it seems that it is blockage free, the only thing that I can see is tiny metal specks where the screen should be. They look like little flakes of aluminum?

Anyone think its bad to leave the tank screen free, or should I try to find one to put in?

I also put a clear line on prior to the fuel filter so now I should be able to narrow my air issues down better.
83 Rabbit 1.6L NA
202,000 miles
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