Odd diesel Rabbit starting problems

[DanHoug]

just fyi... the starter bushing remains in the block when starters are swapped as it is a bushing pushed into the recess the nose of the starter fits in. the last starter i bought had the $2 bushing with it and a tag that said "No warranty issued on this starter without replacing the starter bushing prior to installation." it's that important because it keeps the internal parts of the starter in alignment during cranking, preventing the armature from dragging on the field coils.

but 4 ga. cable is used on boomer stereos nowadays... with the battery in the trunk, i'd go with 00 or greater. had a Fiat Spider with the battery in the trunk and skinny cables for those mild Italian winters.. had to switch to some real copper meat for northern MN.

-dan

[Fatmobile]

Where are you connecting the ground cable?
The stock trany mount location is weak.
I connect to the starter's top mounting bolt.

[DieselAlltheWay]

Hi all, after nearly 3 months of ignoring the car due to other commitments I'm ready to try and get it running again.
It would seem that the consensus here is that the 4 gauge wire I used to be too small so I'm going to try something thicker. Before I go out and spend the money want one last piece of advice to ensure I'm not getting the wrong wire (as in, too thick?).
Seeing how the 4AWG produces .8152 m/m of resistance I thought a good bet to be the really thick 1/0 (or 0 AWG) which produces .322 m/m. This wire is 8.25mm thick, compared to the 5.2mm 4AWG so do you all agree that this is a good way to go? Hope it isn't too thick to feed through the car.
So I'd be using this for the positive right? As stated earlier I had also gotten another 14' of 4AWG for the negative and connected it to the engine bay, which seemed to help. I wonder if I'd be better off doubling the negative by using 2 of the 4AWG wires. After all I'd have one extra 14 length of the 4AWG wire so I figure might as well use it. If so, what's the proper way to do this? How do I physically connect the two together to provide the most current with the least amount of resistance?

Hope this works this time but also looking for input in case someone disagrees with the above. Thanks

[DieselAlltheWay]

just fyi... the starter bushing remains in the block when starters are swapped as it is a bushing pushed into the recess the nose of the starter fits in.
-dan

Dan, I don't think the bushing to be the case due to the car starting fine a few times then dying while on the road. Which suggests poor voltage running through the wires. But I'll try that next should the thicker wire not work. A Fiat Spider huh? lucky guy. Still have it?

[bscutt]

Yes I would parallel up the 2 4 awg wires for the ground along with the 0 awg t the positive side. You can't get too low resistance in those connections. At the current draw of the glow plugs plus the starter motor, any little resistance in the wires translates into significant voltage drops.

[wmasscaddy]

Did you just say it sometimes dies for no apparent reason? If the electrical system was so sketchy it couldn't keep it running, it's unlikely it would ever start. Unless the problem was very intermittent. Stalling out makes me think the problem lies elsewhere. Have you tried putting the battery up front/ strapped to bumper & using stock cables yet? That will rule out everything else.

[DieselAlltheWay]

Did you just say it sometimes dies for no apparent reason? If the electrical system was so sketchy it couldn't keep it running, it's unlikely it would ever start. Unless the problem was very intermittent. Stalling out makes me think the problem lies elsewhere. Have you tried putting the battery up front/ strapped to bumper & using stock cables yet? That will rule out everything else.

I stopped by the car once to try and do what you said, put the batt up front to rule out the voltage drop. But honestly it was a lot more work than I expected so I didn't go ahead with it (my friend had done the mod but has since become too busy to do much anymore). Yes, I agree that ruling that out to be a good idea. Let me describe what happened and maybe someone could confirm if this is a symptom of a voltage drop:
When we first got the car fired up, it seemed to start fairly easily (once the pump was primed and all). Seemed to idle fine for a while but as I recall it then died after a few minutes. It was a bitch to get it started again, this with another car boosting it. I had thought the batt was bad but when I brought it to a shop to have it charged, I was told it had a full charge. At that time the negative was placed at the hatch, near the batt. Friend used the digital voltmeter and it turned out the negative was weak, don't recall what we got but it was less than what it should be. So I bought another 14' of 4 awg wire and put the neg at the engine bay, tested the voltage and all seemed normal. The car started fairly easily so we thought the problem had been resolved. I drove it around the block and all seemed fine. Since the car was still cold I didn't push it, so I can't testify to the power of the 1.9L engine as I was taking it easy. Then after maybe 500m or so it just died as I was driving. Coasted to a stop and it wouldn't start, no matter how much I cranked. Got the Cabrio there and tried boosting it. Tried for a long time with no luck. So the car's been parked at the same spot for nearly 3 months now, hoping that either me or my friend would find the time to work on it, which hasn't happened. Could it be the timing? I don't know but my friend insists that he checked and rechecked the timing several times (he has the tuning tools and followed the procedure). So at a first glance it makes sense to point the finger at the voltage drop, especially in view of the input I got from the users here and their experiences with a long run with a thin 4awg wire.

I'm not crazy about swapping the wires in order to put in the stock wires but I'm willing to give it a shot if it can be made easy. Could someone help me figure out where the pos would go as well as the neg? I can put a spare batt in the engine bay somewhere and don't care if I have to drive with the hood partly open for a while. Thing is, there seems to be a lot more wire going places than just the one I thought goes to the starter. Do I need to hook all that up? Or is there a shortcut I can take?
Again, thanks for the help with this.

[the man 53]

If it just died and never wants to fire are you sure the fuel seliniod is getting power? I didn't read the first page so if that was covered there sorry. Sounds like it isn't cranking fast enough, no fuel, or timing and you said your friend checked timing.

[bscutt]

Well here's the deal on what power you need to make it run:
1) you need good solid power to the positive lead on the starter from the battery (the big lug)
2) You need similarly good ground to the starter body or engine ground
3) You need +12V to the IP solenoid to turn it on
4) you need good 12V power to the glow plug rail for about 15-30 seconds before cranking
5) you need to put +12V to the small spade terminal on the starter to make it crank (normally comes from the key switch but can be jumpered)

Basically that's all you need to make these start and run if fuel supply is ok, compression is decent, and timing is good or at least real close.

So if you can rig up battery leads to the starter big lug, engine ground, then jumper the solenoid on and get power to the glow plug rail, all you need to do is get the starter motor to crank and you should have met all electrical requirements to make it run. That's what makes these cars so simple in my opinion

[TylerDurden]

^^^ Agree. ^^^

The fuel cutoff solenoid can be hot-wired to a small 12v SLA in the cabin or engine compartment. After that, once the engine is started, it should run for a long time. The solenoid draws very little power.

It seems fuel supply is a possible issue, so clear fuel lines to check for air are a good idea.

[Fatmobile]

Sounds like a fuel issue to me.
A vacuum gauge on the fuel line can help troubleshoot those.

[wmasscaddy]

Just to beat the solenoid thing to death in case that's the issue: The fuel shutoff solenoid is the cylindrical thing on top of the IP that has a wire attached to it. With the hood up, you should be able to hear it click when the key is turned to "on". You may have to get your ear between the hood and windshield, with your arm in the window.

If you dont get a click, first use a wire to bring 12v directly from the battery to solenoid. If it clicks, then the car will start and run, but it WILL NOT STOP WHEN YOU TURN THE KEY OFF. To shut it off, disconnect jumper wire or short it out to the body of the IP. Or stall it out with 3rd gear.

If that doesn't make it click, then take the solenoid apart and remove the spring and plunger. Now the car will start and run, but it WILL NOT STOP WHEN YOU TURN THE KEY OFF. So stall it out with 3rd gear.

Tyler- what is an SLA?

[TylerDurden]

SLA = Sealed Lead Acid (battery).

[DieselAlltheWay]

Here's another update - a delayed one, seeing how our second son was born last week and as you can imagine time is so short.
The problem continues but after testing things as best as possible we managed to eliminate all of the issues brought by you fine folks here. The thing that appears to be the problem is a short somewhere. This short circuit is happening between the key hole and the starter. Even after boosting as described by you guys the car won't crank. In fact the lights shut off as I turn the key, this while getting plenty of 12V throughout all the systems.

So the only explanation is a short somewhere and I believe I know what the culprit is. Yesterday I had the car towed here to my place so I no longer have to drive cross town to play with it. In the coming days I plan to remove the cluster and investigate the wiring there as I believe this is where the problem lies. My friend recently installed the MK2 cluster with a tach from my 88 TD Jetta (poor thing died last year) and my hope is that somewhere in there a wire is shorting, causing things to not run. Just a fyi, the car did run fine for a while till it suddenly died while in motion. Suppose a short could cause that. Hope it will be an easy fix, just need to take things apart a bit and check all the connections. Will update once I find the time to remove the cluster.

[82vdub]

Congrats on fatherhood x2. I went and read your initial post and browsed the comments. Are you still having cranking issues or now is it a starting issue?

If it's a cranking issue, you're getting power to the starter, just that it clicks and doesn't crank over, and that the battery is still in the rear of the car.

Did you try my remote starter idea? Here's what happens when you buy a remote starter test switch and try to use it. A remote starter takes power right at the starter via the cable to the battery to pull in the solenoid. It bypasses 100% of the factory wiring. If the problem still persists with a remote starter, it can only be an electrical or mechanical issue related to the starter, solenoid, battery, cables, or connections, or interface with the engine/trans (ie misalignment etc). 100% of the factory wiring is removed from the equation and effectively isolates any problems either at the starter to the battery, or in the wiring of the car.

Have you measured voltages at the starter without cranking it and when you try to crank it?

The headlights shutting off on a VW is part of the load reduction relay that kills the headlights, radio and heater fan (I believe). It's to remove high loads from the system when activating the starter motor. Sounds like this is functioning correctly to me. If you have not used the remote starter to isolate all other electrical, then I would suggest this (make sure the car is in neutral though). Check for voltages and try the remote starter and post your results.

If it's a starting issue, did you bottle feed the inlet fuel line to remove 100% of the fuel distribution system to the IP and hotwire the fuel solenoid? This isolates where in the fuel system the problem lies and shows you where to troubleshoot from there.