Problems with drivability...stalls, won't restart hot, etc

[tjamesj]

I am new to the forum, and am seeking some advice. I have an 87 Vanagon GL Westfalia 2.1L and have had various problems with it running since I bought it in May. It has about 115K on the original engine. and has had all the grounds replaced, battery has been checked, and some normal tune up items have been replaced - dist, coil, plugs and wires done a few years ago by PO, but since that time it had only been driven 5K or so. I have been reading through many of the posts but haven't found anything that addresses all of my various issues. I hope you all can give me some advice. I have a decent local VW mechanic who I am hoping to steer in the right direction... I did replace my power window regulator last week with the help of this forum, so thanks for that!

1. Periodically, after short runs, like 10 minutes, it won't restart after turning it off for a bit(10 min to 20 min). It will turn over normally, but won't fire. Time usually helps - if I give it an hour, or sometimes less it starts normally. Always starts great cold. I have push started it after this happens and if it had a chance to cool down, it ran fine.

2. It has recently started dying after running at higher speeds for an hour or more. All of the sudden, it would not let me keep the revs above 3K. When I would try to accelerate, it would bog down, until finally I have to slow down and pull over and as I am coming to a stop the engine shuts off. Sounds like the Vanagon intermittent syndrome I read about, except it won't restart after it dies. It will turn over, but not fire. I had to let it rest for a bit -waiting 20 min did the trick last time. I had the grounds redone after the first time it died, but then it died again....

3. On my last trip, it drove ok for a couple of hours, although I could feel it hesitating once in a while when I would re-accelerate. Then we stopped and turned it off for about 30 minutes and it barely started. It was pretty hot outside, and I don't think that it engine cooled down much in that time. I got out of the parking lot, but then it died as I tried to get on the road. It would not restart -turned over, but would not fire. So I got push started and then it ran super rough, a bit of black smoke for a few seconds, and ran rough until we stopped about 20 minutes later. I could barely keep it from stalling out when I would stop and start out in first. Keeping the revs high was the only thing that kept it running. Then I let it rest an hour, and it restarted and ran normally for a 10 minute drive home.

I don't know if these items are related or not. And I hope I have included enough detail. My wife and I love the van, but fear of getting stranded in the woods with our 10 month old boy is a bummer!

Thanks,
Todd
'87 Vanagon GL Westfalia 2.1L
'01 Volvo XC 70

[stormforge]

#1: Have you changed your fuel lines?

Could be a variety of problems. First thing to figure out is, when it won't start, is it because of a lack of fuel, or a lack of spark? If the engine has both those things it will usually at least start.

Keep some tools handy and the next time this happens you can try to diagnose it.

I usually check for fuel first. My favorite test is to spray some starting fluid in the air intake and then see if it will turn over and run briefly. If so, it's not getting fuel. You can also open the little bleeder on the fuel line T near the fuel-pressure regulator and see what comes out (or attach a fuel pressure gauge) -- you have to be careful with this procedure on a hot engine. If no fuel: check pump, fuel lines, injectors, filters, etc...

If you have fuel, the next thing to check is the spark. Remove a spark plug wire and check whether it will spark against a solid ground when the engine is turned over. If no spark: check wires, distributor, coil, etc...

Come back with more info and you'll definitely get it sorted out.

Cheers,
-Bill
'89 Syncro

[Howesight]

Hey Todd:

Welcome to the Samba. I had similar problems on my '86 syncro. John, of Van Wonder auto service in North Vancouver BC told me that the problem was likely my ECU. He said that the harness attaching to the ECU exerts pulling/pushing on the ECU circuit board where the harness attaches to it. It then creates a small crack in the circuit traces and if the harness moves, or heat causes expansion, then some of the circuits go open and the ECU goes into limp-home mode or causes a stall, depending on which circuit goes open and for how long.

The most important tell-tale sign that your problem is the ECU is that when the engine is acting up, your tach needle will bounce all over the place as though your ignition was being turned on and off.

If anyone you know can lend you their ECU (one that is known to be good) for a test, do the swap and test. Otherwise, do as follows below.

The fix:
1. Disconnect and dismount the ECU;
2. flip the ECU so the side that was at the top is now at the bottom, but the harness connection is still facing rearward;
3. Drill new mounting holes as necessary to attch the ECU;
4. Turn the harness 180 degrees and re-connect it to the ECU;
5. Re-install the ECU mounting screws in the new holes you drilled.
6. Enjoy your no-dollar repair.

This worked for me and apparently for John on 90% of ECU's with the same problem. The harness now puts an opposite force on the circuit board, thus closing the cracks that were previously opened with movement or heat or what-have-you.

Good luck!

[alnvilma]

I've had two Vanagons and the hot start problem was a $5 fuel pump relay (inside the high voltage box). They can get weak w/o complete failure. Good luck

[tschroeder0]

Here's a few thoughts:

first get more info when it happens; pull a plug to see if you're getting spark or not, pull a injector to see if you're getting fuel (don't point it at anything hot and have good ventilation!).
when it starts to have problems can you pullover and will it continue to idle?

Check the wires(3) going into your distributor, they go to the hall sender, are small, and can crack and ground out = no spark

Check and/or replace your catalytic converter, it can break up and plug the exhaust outlet and cause the slow deceleration you describe

Make sure your fuel filter is new

Replace your ignition switch (they are cheap)

as stated, replace you fuel relay(s)

Listen for your fuel pump to cycle when you have these problems(it cycles at the first "click" of the key when turning to start the engine), if you don't hear it, get under there and check the ground and hot wire going back to the plug in the harness, the routing of the hot wire is crappy and over time can wear and then ground out. Good luck!

[tjamesj]

Thanks for all of your responses!
Bill - I haven't replaced the fuel lines, and they could be original, or at least older than 10 years. When it happens again I will try your diagnostic tips.

Howesight - The ECU problem you describe sounds similar, but my tach needle does not jump around at all. It seems to match the engine speed.

Alnvilma - The relays sound like they are worth a shot - thanks!

Tshcroeder0 - When it is dying and I pull over it usually completely dies. One time I stopped quickly when it was acting up and it stayed running, so I quickly turned it off and restarted it and it drove a bit better. I'll check the wires, cat, relays. I'm sure the fuel filter has a couple years on it.

Anyone think the fuel pump itself could be the culprit - at least for the dying after an hour or so issue? Are they known for acting up when they are hot?

Thanks again,
Todd

'87 Vanagon GL Westfalia 2.1L

[westyman71]

I have had 2 Vanagons in the past that would get "wonky" on a hot start.

Next time it happens, when you restart the engine, turn the key to "ON" and wait a few seconds until you hear the fuel pump cycle. Then turn the key to engage the starter.

Both those other Vanagons would not start if you immediately jumped in when hot and just cycled the key to start.

I kept them both for a long time and didnt replace anything. I just knew what to do.

[tjamesj]

Sorry for the very delayed reply, but I've come to appreciate it when the original poster replies with the solution. So better late than never.....

In my case the problem was fixed with a new fuel pump.