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Tue Jun 10, 2008 8:14 am

how to explain.....here goes. ive had my 86 vanagon for about a year and have had the same problem the whole time. while driving down the highway the van will just cut out. it may just hickup and then keep running... or it may do that a few times in a row... or it might wait till ive deccelerated then restart.... or it might stay stalled until ive pulled offf the road and restart right away... or it might not want to start again for a few minutes... or it might do all those things when im not on the highway butat lower rpms. now... it might decide to do this every 5 miles or it may not decide to do it for a thousand miles. sometimes when its pulling its shennanigans several of the electrical components (distributor, fuel pump relays, and the wiring harness junction box) will intermittently buzz with an eerie sparky kind of sound...then presto... it stops and the van is fine for another 2 to 2 thousand miles. HELP ME PLEASE i know someone else has had similar gremlins and knows how to exorcise them.

Tue Jun 10, 2008 9:30 am

Mine did that and it turned out to be a bad hall sensor in the distributor.

Tue Jun 10, 2008 10:38 am

Welcome.

This is some stuff on how to fix the problem...

http://www.geocities.com/harald_nancy/intermitt._syndrome.htm

http://www.benplace.com/vanagon_intermittent_syndrome.htm

Tue Jun 10, 2008 11:12 am

I think that I have the same problem and I think it is the hall sensor also. I did a post and had some replies indicating the hall sensor as the problem. I am at the point of purchasing a new one and installing it. As my engine quit running I noticed erratic tach indications and that is why I think the hall generator is the culprit. Several responses suggested checking the condition of the wiring harness where the three wires go into the distributor. If those wires short or cross connect it would probably cause the same symptoms. Or it could be the harness or the computer.

Aloha
tp

Tue Jun 10, 2008 11:22 am

here is my post and replies

more questions '87 Vanagon wiring harness

Aloha
tp

Thu Jun 12, 2008 10:31 pm

ok i had similar symptoms and suspected the hall generator. The mechanic had said the wiring harness was bad, but i bought a distributor at auto quest and uncovered my distributor. The hall generator was held in place by silicone sealant and wiggled in it's seat, the wiring and connector was ok. I installed the new distributor with the new hall generator, but forgot to put in the rotor. as i was putting my tools away i noticed the rotor and put it in the distributor, but now i've discovered i forgot the dust cap. The new distributor is aligned in approximately the same position as the one i removed. I reconnected the battery and attempted a start. alas it did not start and my timing light is in california.

I think my mystery/phantom problem is resolved and when i can set the timing properly the engine will start and run for another 30,000 miles.

Aloha
tp

Fri Jun 13, 2008 7:14 am

chrismon wrote: how to explain.....here goes. ive had my 86 vanagon for about a year and have had the same problem the whole time. while driving down the highway the van will just cut out. it may just hickup and then keep running... or it may do that a few times in a row... or it might wait till ive deccelerated then restart.... or it might stay stalled until ive pulled offf the road and restart right away... or it might not want to start again for a few minutes... or it might do all those things when im not on the highway butat lower rpms. now... it might decide to do this every 5 miles or it may not decide to do it for a thousand miles. sometimes when its pulling its shennanigans several of the electrical components (distributor, fuel pump relays, and the wiring harness junction box) will intermittently buzz with an eerie sparky kind of sound...then presto... it stops and the van is fine for another 2 to 2 thousand miles. HELP ME PLEASE i know someone else has had similar gremlins and knows how to exorcise them.

Replace:
Ignition switch.
Main FI power relay.

Check, clean, reconnect firmly:
Diz wiring connectors (as Tom said, watch if the tach dropping precedes the engine dying by a fraction of a second. No tach? Then WHAT TIME IS IT?).
All engine grounds beneath coil, on block, and at ECU.
Connections at ignition coil.
Connection at ECU.

Sat Jul 12, 2008 2:54 pm

I think my 87 vanagon is doing the same thing as Chrismon reports. I've changed out temp sender II, fuel pump relays and air flow meter. I've also temporarily disabled the idler motor. Still the problem persists. It stalls 3-4 times on my 3 1/2mile trip to work. I have a fuel pressure gage on the system and observe ~35psi while idle, approx 30 while underway. Shortly after the stall when the chatter/buzz/clicking starts the fuel gage meter bounces around as it drops. (I think that's when the injectors are unloading fuel and flooding the cyclinder.) I next plan to check the ground at fuel pump and other grounds, but the van is not exhibiting the bucking like when I had a ground problem 10 years ago. I may swap out the hall sensor next - although my VW mechanic doesn't think it's the likely cause--thankfully he's been very generous with loaning me parts, so I think we'll give it a try. Chrimon, have you solved this problem yet??
Thanks,
dp

Sat Jul 12, 2008 5:46 pm

Yours sounds very much like an ignition switch. I'd do that before anything else, it's cheap and an easy job. They fail like that all the time. Your fuel gauge fluttering is the tell.

Do you have a heavy keychain?

Mon Jul 14, 2008 5:26 pm

I'm still trying to fix this problem...
Just changed the Hall sender, and it didn't even try to start...
...Until after work today, after the van has been sitting dead for almost two weeks, it fired right up.

It's very confusing

Mon Jul 14, 2008 9:17 pm

Thanks tencentlife for your response and suggestions. I spent yesterday afternoon doing all the fuel injection system diagnostics listed in Bentley. All sensors and wiring checked okay. I replaced the temp sensor and swapped out the air flow sensor - still the stall and flooding persisted.

I reviewed results with my mechanic this morning and he suspects the computer. He was kind enough to go out to his synchro and pull his ECU to loan to me. Since the swap the vanagon has performed without a stall. I didn't note in my earlier posting that my catalytic rattles and I probably need an OX sensor. I have a catalytic on order. My mechanic would like to see me replace the catalytic and Ox sensor before going for the ECU replacement--just in case.
In the mean time he's suggested I open up the ECU and look for failures. Does anyone know any details about the guts of the Digifant? I work with electrical engineers. We'll look for the obvious, but I sure would like a schematic of the digifant?
Does anyone have any leads on such details?

Tue Jul 15, 2008 9:16 am

Hah. Good luck with that.

Wed Jul 16, 2008 6:47 pm

With nothing to lose I dove into the ECU and found the source of the intermittent stalling and flooding. Some won't believe how simple and inexpensive this fix is. The boards of my ECU had some solder joints that looked like they were rusted. But there's no steel or iron on a PC board. I conferred with two colleages each with 25 years + of experience with design, build and testing control circuits. They told me the brownish stuff was flux residue. They also told me that 20 years old electrolytic capacitors could be failed. - but I addressed the easy stuff first. With the guidance of an electronics technician I cleaned and scrubbed the board surfaces and solder joints with Flux-off and an anti-static plastic brush the size of a small toothbrush. I would have been very gentle with he scrubbing but these experienced people scrubbed vigorously and agressively with lots of the solvent dripping off the ECU boards into a garbage can.

Once clean, I let it dry then buttoned it up and installed it in my vanagon - and it's been running PERFECTLY since. I say perfectly, because there appears to be no stalling and flooding, but also no little skips or any hesitation in these two days since the fix--as if I did a major flush of the whole system.

My thoery is that some of the solders joints were completed by hand and were left with a lot of flux residue. My electronics friends says that 20 years ago there was a lot of "junk" in some flux. I think it may have been a little corrosive. The impurities in the flux may have attacted the solder and created some oxides. Over time the oxides settled and moved in the flux that bridged between solders points. Oxides are semi conductors and I think they started "semi-conducting" currents between solders intermittently. Gremlins. My mechanic commented "I wonder how m any $500 ECU were replaced when they may have only needed a cleaning."

Anyway that's my theory. Only things I would add, I don't know much about the solvent so take precautions as it smelled quite nasty. Also, be careful not to fry the ECU microproccer with a stray static discharge. It wasn't a problem for me in this humid Maryland summer (I guess it is good for something) , but you may want to ground yourself before opening the ECU and while cleanig it if you work during winter or in a dry climate. I think the Flux-off or some other flux cleaner and anti-static brush should be availible on-line or from a good eletronics supply.

Now I just have to repair a leaking R&P steering gear and a CV boot. Always something.
Thanks again.
Daniel

Wed Jul 16, 2008 8:21 pm

Sounds like another Vanagon cottage industry in the offing.

Thu Jul 17, 2008 6:20 pm

I kinda had the same problem, and I posted on here, and the advise given to me was to check, clean, and adjust the throttle position switch. I went ahead and did that, and now the van runs excellent, and also gets very noticeably better fuel mileage.

Fri Jul 18, 2008 4:43 pm

I have had the same problem on my 89 hiccup, stall, runs in 3 cylinders...

the culprit is spark plug cables.... try them 1st because they are not expensive

good luck

Tue Jul 29, 2008 12:21 am

Greetings!

I need help, too- My 1986 Vanagon was running strong and fine up until about 2 weeks ago; I had the same "cut off" and/or "hiccup" while rolling at highway speeds for a while, or it would feel like a "drop in compression" for a second, then come back in feeling strong as ever.. Its been stuck in the same place for the last 2 weeks after I parked in front of my buddy's house.. It wants to start, but doesnt- as if it were out of gas.

1) I replaced the ECU/ECM computer- same result..
2) I replaced the Air Flow Meter with another good 86 one- same result.
3) Replaced/traded the fuel pump with that of my air-cooled 81 Vanagon- same thing..
4) Replaced/traded the ignition coil AND ignition switch(in steering wheel column) with the working ones from my 81.. same problem..
5) Bought one new fuel pump relay- but dont know where it goes!

I dont how to check for a spark, or how to check the "Hall Sender/Sensor" in the distributor.. But I can learn- but can anyone at least tell me where the fuel pump relay goes? I also heard the same crackling/static sound from my fuse panel just left underneath my steering wheel... My Bentley repair manual only goes up to 1983, and I dont have a key to tell me which fuse and relay goes to what...

Thanks for the help in advance..

Tue Jul 29, 2008 3:57 am

tencentlife wrote: Sounds like another Vanagon cottage industry in the offing.

O.K., I'll bite.....what does this saying mean?!?!?!

On a side note to the above post, I had a quirk in the idle, and the occasional stall when I first brought back my Vanagon from Germany. I found that it was a loose connection of the coil to distributor ignition wire. I had just replaced the spark plug and coil wires. I used a pair of needle nose plyers to expand the copper leads so the wire would make a good, tight connection into the coil and distributor cap.

So, it sounds as if these types of intermittient and irratic cutouts and stumbles could be many issues. The ECU having leftover flux is a new one to add to the list though. I have a good working spare.

Tue Jul 29, 2008 9:01 am

Well the spirits are indeed acting up here. The fuel pump relay is in the black box on the driver's side of the engine compartment. Test for spark; have a beautiful assistant sit in the driver's seat ready to start and STOP the act of turning over the engine. Unplug the center ignition wire from the distributer and hold it about 2" back from the end. Hold it about 1/4" from any big chunk-o-metal, like the AC bracket. Have your assistant crank it over and you should see a spark jumping from the end of the wire to the chunk-o-metal.

Or you can do it my way, have you son misunderstand your directions while you have the wire in your hand, nowhere near any metal. That way the spark passes through your body. Very easy for him to run away from your vengeful grasp, as running while convulsing is tough.

Get the Protraining Manuals and do the tests on all the circuits. Defiantly search for bad ground here and clean yours up. The Fuel Pressure Regulator should also be tested as outlined in the books. When it stalls, or 'hiccups', does the tach drop to zero and immediately go back to wherever? If it drops to zero, then the Hall sender or its heat cracked wires and/or the plug on the side of the distributer could be to blame.

The coil in your 81 is NOT the same as the 86. Get the proper coil. Putting a 27 year old ignition switch was a waste of time, they cost $9.95. Get a new one. The clicking sound is most likely the unloading relay, which is mounted above the fuse panel and grounds on the A pillar. It likes to cycle on and off from a bad switch or grounds. The grounds in the two clusters can also be bad from windshield leaks.

If you have not seen this before, get these and read through them, do the tests:
If you want your own set of Protraining manuals for free, go to my public folder and get:

86 Vanagon Protraining.pdf
Vanagon Protraining 86-91 Fuel Systems.pdf
Vanagon Protraining Digifant I 86-91.pdf
Vanagon Wiring Diagram.pdf

http://homepage.mac.com/WebObjects/FileSharing.woa...mp;lang=en

Tue Jul 29, 2008 9:40 am

Thanks so much for the Vanagon wisdom! I'm so appreciative for all the excellent info, from the distributor spark testing, using needle-nose pliers to tighten up the connections, to all the awesome links to the diagrams! I'm still digesting them! I'll let you know how things turn out once I get back to my '86..