No start. Fuel or timing?

[jkmackenzie]

Hi there,

This is my first post, but I'd like to say that I have been circulating around here for a while and have enjoyed the great base of knowledge floating around this forum. Apologies for a long first post.

I'm having difficulty getting my 91 TD started.  She has 504,000km but has been very solid until now.  I've had her for 4+ years and she has a brand new 850CCA battery and the timing belt & tensioner were done by VW within the last 20,000km.

I figure that it is one of 2 things: fuel or timing. I would consider myself to be an 'intermediate' home mechanic.  Fuel problems are within my realm...timing issues are new to me.  So I am starting with a fuel system breakdown and am coming up short on answers, and your help would be greatly appreciated.

I have found a similar story here:
http://www.vwdiesel.net/forum/index.php?topic=17883.0

But not all of my questions are answered.  Here's the story:

Day 1: 15 degrees C and wet outside.  Started no problems and drove for the afternoon doing errands.
Day 2: Almost exact weather conditions. Turned over but would not start.  She would kick and "want" to start, but could not get it going.
Day 3: Figuring it was a fuel issue, I:

Checked voltage to Stop Solenoid ("click" on key)
Checked for any looseness or leaks around the IP
All clear lines to and from IP and filter pulled and checked.
Replaced fuel filter
Filter to water separator line pulled and checked. There was a blockage in that section, but I blew it clear.
Water separator to tank pulled and checked.

The temperature was warm enough that I did not spend my time on checking the glow plugs.  I put it all back together, and eventually did get her to start, only to have her quickly die and not start again.  I figured that I had put the lines back together leaving a fitting loose. So, I:

Pulled all lines again and blew them clear with a hand pump, including the water separator.
Replaced the tank to separator line.
Pulled and checked the fuel gauge sender and suction assembly.

With that done, I then confirmed that fuel was getting to each injector by cracking the connection to the top of each one individually and turning the car over.

Nothing.  Same as before...she turns over and over and over.  There are moments of slight "stumbles" but nothing more.  There is fuel in the clear return line, I can see it moving as I turn the car over.  There is plenty of exhaust as I turn it over, and it appears to be a normal colour.

From my research, my next actions will be to:
Double check the solenoid (as suggested in the above post)
Check the IP timing
Compression test (??)
Pull the injectors (would all 4 go at the same time??)

Thanks for any input!
Jason

[burn_your_money]

Push start it and see if it will go. I'm suspecting an elecrtical/starting circuit problem.

If you have smoke out the back, and fuel at the injectors your fuel delivery should be good enough to start it.

[jkmackenzie]

Thanks for the quick reply.

I suppose that's a possibility, but I can crank it over and over until the battery starts to fade.  Crank speed during that time is strong and constant.

 

Jason

[burn_your_money]

You should check the glowplugs, they do make a difference even when it's warm out.

I still think you should push start it and see what happens

[jkmackenzie]

Thanks Tyler, i'll try the glow plugs and push start this weekend.  Any other ideas?  I usually only have the weekends to work on her, so I'd like to get as many tests organized as possible.

Jason

[Doug]

I sounds like you have the fuel circuit checked out okay.

Check your glow bus for voltage. Earlier models had a fusible link supplying the glow bus circuit that sometimes failed. I am not sure about the 91 model. There may be a fuse in that model. The other option is replace the glow relay. Contacts are often destroyed or the internal logic circuit that controls the relay fails. A quick test for that is to jumper the glow bus (if there is no voltage there on a start cycle) directly to the battery for 20 seconds only. Then crank the motor. I had to replace the relay this season that worked one day but failed the next. The yellow LED on the dash display still seemed to work properly.   

[theman53]

I would definately check the Glow Plugs. It seems as if the fuel system checks out, but watch to see if there is ever any air in the return lines if you have clear ones...there should be no air. If the Glow plugs check out and the above mentioned fuse is ok, then I would go see if the timing is messed up. Get a reading where it is now and if it has retarded then advance it some. You should be ok. I am betting the glow plugs are junk. I had my 81 that would start fine and only #1 GP was working, but my 84 needed to have 3 in warm months and all 4 to have a chance in the winter.

[jkmackenzie]

Thanks guys, i'll definitely do a check of the glow plugs and circuit this weekend.  I had kind of discounted it and put it at the bottom of the list, given the warm weather.  The glow plugs themselves were replaced about 3 years/40,000km ago.

theman53, there did seem to be a bit of air in the return line...that's how I could tell it was flowing through the IP (my vantage point was the driver's seat). My timing experience is nil so i'll have to do some reading and then have a look at that as well.

Jason

[jkmackenzie]

Well if I didn't have a glow plug problem, I do now.  The nut holding the glow plug bus bar to the gp on cylinder #4 was rusted.  In trying to remove it I ended up turning the end off of the plug.  I still can't get the bus bar off to test the other plugs.

In other bad news, I pulled off the air intake all the way to the turbo (just to eliminate all possible causes) and found this:





The turbo will spin, but there is some resistance and a slight amount of play in the shaft.  Not what I was hoping for.

Could this be the culprit of my non-starting engine?  I'm presuming that all that oil from the turbo is now in my cylinders.

[burn_your_money]

That's not a lot of oil. I wouldn't worry about it. Most of that if not all of it is from the CCV system.

Ah the breaking glowplug trick... Use a pair of vice grips on the part that came out of the glowplug and then you should be able to undo the 8mm nut.

[jkmackenzie]

Wow that's a surprise and relief  Thanks Tyler, you made my day!

Any trade secrets on getting the glow plugs out? I'm having a rough time getting my tools in to take off the nuts.  Do you pull off all the injector lines or work around them?

[burn_your_money]

for sure pull the injection lines.

The other secret it grease

[turborabbit]

Hey, JMack, you did the right thing, starting with fuel. My rule of thumb is first check the fuel, then glowplugs (even in the tropics), then check compression. Did you push start it? Running compression is not starting compression, but once the engine is hot it will usually re-start. For while. I hate mechanicing more than most, but I love driving these cars, so I do it myself with a Bentley and a couple of specialty tools. Good luck-warren

[jkmackenzie]

Well I figured it out.  I haven't had much time to put into the car, hence my time away from the forum.  Thanks to you all for your great input.

After pulling the fuel and air systems apart looking for culprits, I finally took a look at the glow plug system (outside of a quick initial look).  I was sure that wasn't it, but was wrong.  In the end it was the in-line fuse (metal strip on the engine side of the fire wall).  I feel a bit sheepish for not going through the glow system more thoroughly at first, but lesson learned I guess.  The advantage to this is that I learned some new stuff, right? To be fair to myself, there was a blockage in my fuel line when this all first happened, so that had me fixated on fuel, which was definitely part of the original problem.

NoSurrender, I did crank the hell out of it a number of times, but luckily with no (immediately apparent) repercussions.  With a new '05 TDI and not a lot of free time i'll be selling the '91, so I'm glad to have her running again. Thanks again to everyone for your help.

Jason

[burn_your_money]

Glad it was a nice simple fix