Hard start in morning

[92Wolfsburg]

Hi all, my girlfriend just bought a 92 Jetta Turbo Diesel (I'm pretty sure its the Wolfsburg...its made in Germany). It's in nice shape, has 380,000km and we got it for $1000cdn safetied!!! I have been reading through this site and I bought a bently manual off e-bay and have been puttering with it a little bit. So I've got a couple of q's...

My Bently manual only covers vehicles up to 1990...are there any differences on the 1992 Jettas I should know about?

It's been hard to start in the morning even with temps slightly above freezing. I changed the fuel filter, air filter, oil change with Castrol Syntec VW oil and a couple other minor things. I discovered that the glow plugs were not working...the light would stay on for like 35seconds even if it was warm....I performed all the tests in the Bently manual and they all checked out. When I reconnected all the sensors and relay, the glow plug light started behaving normally, lighting up only after a few seconds. I dont have a test light and instead used a multimeter to check for voltage at the glow plug bus...hooking the positive to the bus and the negative to the negative terminal on the battery and no voltage...I think the multimeter may be FUBAR'd though, as I'm using tinfoil as a fuse. I'll buy a test light to ensure they are working...as well as an ammeter to check the current draw. The glow plugs are all brand new, no wear on them at all because the system wasn't working. Any thoughts?

By reading other posts, I'm also starting to think there may be a small air leak. Is it worth it to install one of those check valve squeeze ball thingys? If so where would I install it?

Does anyone know off hand the size of the hoses used between the pump and filter? I'm thinking of replaceing them just to rule them out but I work on the car at my uncle's place which is out of town....PITA to have to come back to town to buy the correct size.

Awesome little car though other than the cold starting problem...we have been getting 40USmpg (47IMP mpg) pure city driving...not bad!!

Oh and the compression is good it was re-ringed 3 years ago.

Thanks for all the info and sorry for the massive post!!!

[Doug]

Check glow plug bus current draw with a cheap series type ammeter or a clip on style one to see about 60 amps or so draw at the start. If not then check each individual glow plug for continuity by lifting the bus connections. Replace the inline fuse link. You can make one out of thin copper foil if you are handy. Check the temperature sender connection on the head to make sure that it is not loose. Check sender for continuity also. Check the relay for correct operation. Chances are the contacts are burnt away on it and it is time to replace it if everything else is good.

[Vincent Waldon]

Yup, we Canadians need our glow plugs all year round, and since it sounds like you've got good compression the glow plug system is  the likely culprit.

If you are lucky they are simply not getting voltage.. confirm your multimeter is working by measuring the battery directly (should see 12V) and then confirm you are getting 12V to the glow plug buss bar when the engine is cold and you turn on the key.  No voltage:  great !!  (much easier to fix than the plugs !!!).  Look for a blown glow plug fuse, bad glow plug relay, or a wiring issue.  Multimeter to the rescue !!

If you are getting 12 V to the buss bar then chances are one or more glow plugs are not working. (brand new or not).  You can confirm with an ammeter (I use a cheap Canadian Tire car dial gauge)... should be 48A at the start down to about 30A as they heat.. but this will just tell you what you already know.  To go further you'll need to remove the buss bar between the glow plugs... 8mm wrench and one of the more knucklebusting jobs on a TD, and you'll need a 17mm to remove the steel injection lines to give you room.  With the buss bar removed you can check continuity or current draw to each plug... 12A to start.  Or remove em all, and use booster cables to connect them to the battery... should glow red hot in a couple of seconds.

The fact that you are noticing hard starts suggests you have at least 2 of the four not working (assuming they are getting power).  Me:  I always replace them 4 at a time... everything is already apart and the other two will go soon anyway!   The brand to get is Bosch.... specifically Bosch Duraterms... latest glow plug technology and seem to last a long time.  IMHO this is not the time for generic parts... I prefer to do this job as infrequently as possible.

Holler if any of the above is unclear or you run into a snag... it's not a hard  job just tight spaces to work in.

Welcome to the wonderful world of diesels BTW... you got a great deal  and should enjoy your purchase for years to come.


Vince

[92Wolfsburg]

Turns out it was the fuse after all. There was no crack visable, but when I took it out it just fell apart. I replaced it with a 55amp honda fuse...dont think the extra 5amp rating will hurt anything. Also, I had to bend the fuse up to get it to fit (less distance between the terminals on the VW as opposed to Honda). Nothing at Cdn Tire would fit the closer terminals. If I have problems with the bent up honda fuses I'll probably just buy a fuse block and use that instead. I guess I could always price the correct fuse... Anyway, thanks for the help guys! Mucho Appreciendo


Oh, P.S. do the Duraterms draw more amperage than whatever was stock? A better, faster plug has got to draw more power right? Just curious...I did a search but could not find anything.

[BlackTieTD]

the 50 amp glow plug fusable link is about 2 bucks at the dealer. nice when its an easy fix!

[farmer]

When you shut the engine off look at the clear large line (fuel feed) if there are bubbles in the line and they flow back to the filter then you have an air leak at a hose clamp or the injector pump main seal is leaking air into the system on shut down.
My 94 Golf has the same problem, there is a leak at my seal letting air in the system on shut down.
Put your ear at the front of the pump by the timing belt cover when the engine is off, if you hear a hissing sound from that area than the injection pump needs a front seal.This may be a further problem becuase if the seal leaks that would likely indicate some internal wear and these are very expensive to overhaul. on mornings that are warm you shouldn't need growplugs.
Best of luck

[Vincent Waldon]

Fuse.... sweet... how come I never have that kind of luck ?!!!!

[mtnbob]

my 86 Golf 1.6 N/A Is impossible to start cold unless pushed or helped, once warm starts easy. I don't see any clear lines to look for leaks in the lines. If I was to install a clear line, where would I put it and what material does the hose need to be so it doesn't melt? thanks
robert

[Doug]

Read all the posts in this thread carefully. Look at your glow system first.

[mtnbob]

would the glow plugs be the likely culprit here in the south? are they even needed when it is 80 degrees F + ?  just wondering. still learning.
robert

[jtanguay]

would the glow plugs be the likely culprit here in the south? are they even needed when it is 80 degrees F + ?  just wondering. still learning.
robert

with bad compression, yes.

[mtnbob]

ok taking it in to the dealership tommorrow to have compression checked and starting diagnosed. I don't think I can check it my self.

[Doug]

Last time that I was in S.C. it seemed to me that there could be some fairly cool nights especially inland towards the mountains. With lower compression you will need the glow system operable. Fix that first and ignore the dealer's attempts to sell you a new engine/rebuild. It will get you going again.

[jtanguay]

yeah... i doubt a dealer would be ready to warrantie low compression...

just fix the GP's and have fun driving a diesel... and be thankful you don't live in the cold climate up north  

[mtnbob]

I was planning on taking it to the dealership tommorrow for a diagnostic. They said they would check the compression and glow plugs and do a general diagnostic for $86. Are you telling me that I can check the glow plugs myself reasonably easily? And then at least rule that out? How hard is it for me to check the compression and timing? Figured a reg timing light wouldn't work since there are no spark plug wires to clip it to. Engine only has 108,000 miles on it, and body is great, but it sat for years until I made it my project.