Start/restart or stalling problems

Capt. Mike

Martin Stebbing Junior Member posted May 06, 2002 11:25 AM

I recently bought my westy and it is in great shape all over but for this one thing.After she is warmed up and I shift gears there is a brief moment when the engine slows right down and if you dont catch it just in time (i.e. floor the gas after quickly slamming into neutral of course)it stalls and I am left waiting for an hour for it to clear.Also turning the steering wheel whilst parked with the engine running can have a similar effect. My mechanic pal has checked the whole ignition system and he can't find anything wrong and the previous owner had a lot of new(OEM)parts installed last year. Also when the engine is warm and you have been stopped (in traffic,or waiting for wife and beasts to get in) a little jab on the gas will cause a little puff of sooty smoke to emerge from the tail pipe. The engine is in fine shape with no pressure leaks around the cylinders,the wiring harnesses,plugs,rotor caps,ect are all new. We just cant seem to work it out and summer fun is on the horizon.Any clues anyone????

Laurence Smith Member posted May 14, 2002 09:25 AM

May be your O2 green wire ground...

I have found that a persistent running rich problem can sometimes be a broken ground of the O2 green coax wire.

The green O2 wire is a coax wire meaning it has an outer sheath that is a ground wire. This ground separates from the green coax inside the wiring harness near the ECU and then connects to terminal 19 of the ECU. Then a brown ground wire comes off terminal 19 and works it way back through the harness and connects to the engine block. If this brown ground wire is broken or shorted to the coax core then the O2 readings sent to the ECU are whacky. The ECU responds (usually) by running the engine rich.

I have some across 2 Digifant systems where this ground wire was not doing its job. I ran a new brown wire from terminal 19 on the ECU back to the engine and grounded it. Actually I spliced the new ground to the existing one as close to terminal 19 as I could.

Problem fixed! No running rich.

Laurence Smith
Hamilton, ON
90 Westy
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Capt. Mike

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jrogers Junior Member posted July 02, 2002 03:25 PM

Last night my '84 Westfalia refused to restart when I stopped and turned the engine off to wait for a road crew's repaving efforts, after having driven about 35 miles. After sitting about 10 minutes, attempts to restart the engine resulted only in flooding. Several re-tries were similarly unsuccessful.

Went back this AM and the engine did start right up, but now the idle is oddly way high. What might be going on here? As a little background, I've only owned the van for a bit less than one month and have been stranded three times now due to alternator failure (since rebuilt), ignition amp failure (since replaced) and now this. Also, during last night's drive, the oxygen sensor light came on, but I've assumed that is just coincidence (?). All in all, it seems the electrical system on this van is systematically going to hell.

Any thoughts or suggestions would be most appreciated.

Capt. Mike

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robovan Junior Member posted July 02, 2002 07:29 PM

I was wondering if anyone with digijet system experience has a working solution for this problem. I don't know if I can contract the vanagon syndrome as my van is an '84 1.9 liter.
I could use some help here.

My fuel delivery system works great and the engine is fresh and snappy but after long drives/high load or high temp days I have noticed some hesitation. Yesterday on the freeway (it was a hot day) the engine shut down. completely. It had gas but was dead dead dead. In the morning it started and ran excellent. I thought it wanted to cooperate. So today I go and drive to a job interview and on the way home boom. it dies again (on the freeway no doubt) and I have to pay for another (2nd) expensive tow home. I hope these symptoms sound familiar to someone. Any ideas?

I would super appreciate any help here.

Capt. Mike Tech Writer posted July 04, 2002 03:20 AM

As an '84, it cannot have Vanagon Syndrome -- that was only on the Digital FI systems (Digifant). Nor do your symtoms match.

If you have fuel, but no spark, I'd first look at the ignition system (Has its own forum) because coils can breakdown hot but work cold. (Happened to me once though not on my Westy!)

Then I'd go through the sensor checks for the FI & ECU listed elsewhere on the site and in the Bentley, especially the temp sensors since you seem to have the problem only when hot.

Capt. Mike

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danrobjon Junior Member posted July 11, 2002 12:46 PM

I have a '79 Camper Van with 80K original miles on it. The trouble I am having is that it runs fine for a while (like 20 minutes) and then floods itself, to the point I can't start it again. I have noticed that it does this under all driving conditions from going down the freeway to stopping at a light. I have replaced the double relay, all of the fuel injectors, bypassed the cold start valve, checked all the grounds (that I can find), inspected the harness to the ECU. STill no luck. I have also tested the airflow meter using bentley. It checks out. Any ideas where to turn? Do I have the dreaded bad ECU? When it floods, it looks like the ECU is telling the injectors to stay fully open. I'm reluctantly to drop $800 on an ECU only to find out that ain't it.

Capt. Mike

If the previous posts on flooding don't anwer your questions, check your Pressure Regulator to see if it is bleeding off the excess fuel pressure as it should. Failure would have excess pressure on the system at all times.

Also check the auxilliary air regulator which provides additional air during start and thus triggers the ECU to send excess fuel. If it continues to provide excess air, the ECU will continue to be fooled into thinking it's in warm-up mode and call for extra fuel.


New member
I have a bit of a problem with my 1978 bus, I was driving through town the other and she died on top of a hill at a red light, I tried restarting her and she ran, then I gave her gas and she died again. I brought her home and started her in the drive and she barely ran at idle, I pushed on the acclerator and the rpms barely rose, I pushed slowly and she reved right up, then I took my foot off the accelator and she died, and now I have to have the accelator all the way down so she'll idle, Please Help, I have no idea what is going on.
With Regards,
J. Walker

Capt. Mike

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whitestarline Member posted July 30, 2002 12:29 AM


I can't seem to get my 1978 westfalia running, I recently installed a rebuilt engine and hooked everything thing up. the starter turns the engine over and the fuel pump flows, but the engine will not start up, I noticed that the ignition coil gets very warm which seems odd to me. Any help of any kind would be much obliged and greatly appreciated.

AWG Member posted August 02, 2002 11:24 PM

Have you checked for spark?

whitestarline Member posted August 04, 2002 05:39 PM

I do have spark, and fuel flowing, but I'm still getting nothing, I had a friend of the family who use to work on vw's re gap the points and it started up and ran for a half hour, then the next day I went to start it up again and nothing. I disconnected the temp sensor and then re connected it and it started up again but when I went to drive her she died again.

AWG Member posted August 04, 2002 09:24 PM

After cranking it for a while, does it smell like gas? Or have you removed a spark plug to see if it's wet or dry? Your fuel pump might be running, but your injectors might not be coming on.
Check all your ground connections, make sure they are clean and tight.

whitestarline Member posted August 05, 2002 12:41 AM

It does have a strong fuel smell, I had her running today and took her out for a spin around the block but she died on top of a hill after about 5 minutes of driving and I had to tow her home, where should everything be grounded? I have a ground from the battery and two grounds (one from the transmisson and one from the side of the engine). is there anywhere else that needs to be grounded?

Capt. Mike

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nickr Junior Member posted September 07, 2002 01:38 PM

Help, My 90 Vanagon GL will not start at elavations above 8,500 feet. The engine will start but when the clutch is let out, the van stalls and engines dies. If I try to restart, the engine will crank but refuses to start up again. If I wait several hours before tring to restart the engine again, it fires right up but dies as soon as the clutch is let out. Had it towed to a lower elavation (5,000 feet) and the van drove perfectly 15 hrs. all the way home. Never had any problems again, that is until I went back above the 8500 feet in elavation. If I don't turn off the motor and drive straight through the higher elavations the van run, but it does feel slugish. The probelm only occurs if I stop and try to restart at the higher elavations. I replaced the air flow meter harness (vanagon syndrom) it has not helped. Checked all hoses for leaks, air filter is clean, fuel filter is new, and fuel pump operating. My mechanic strongly feels that it is my ECU. Before I drop $450.00 bucks, I wanted to check in with the group and see if anyone else had any problems similar to mine.

Thanks -
1990 Vanagon GL
66 Karmann Ghia

Capt. Mike

What have you checked (Guideline #3)? Does your idle speed & CO content adjust for elevation as per Bentley 24.52. How about the throttle valve switch? Failure or too small a gap will give your symptom. How about pressure regulator? It adjusts for manifold pressure, which would be attenuated in high altitudes. The idle stabilizer is meant to adjust for load. Again,high altitudes can give a false load reading. Last, what octane fuel are you running? See the Fuel Octane topic as many mountain areas are selling substandard (for the Westy) fuel as part of their EPA program. The Westy requires a minimum of 87 Octane, R+M/2 method. (The required yellow sticker number on the pump -- don't go by "regular" or other advertising terms.)

Capt. Mike

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hayes Junior Member posted January 06, 2003 12:34 PM

(This is a first time post for me and I wonder if this is a good board. Are there other good ones where I should post?)

I have a 1983 1/2 westy with the 1.9 water cooled engine. Off and on for several years I have had an occassional problem with the engine running rich -- black smoke, everything. I corrected several problems, mostly dealing with ground wires on the injectors and finally seemed to fix it completely when I removed a splice someone had put in one of the injector ground wires and respliced and soldered it.

Now, after months of running well, the engine seems to be full rich when trying to start only. I can start it once when it is dead cold (it's winter in West Virginia, below freezing mostly) but then, when it is warmer I cannot restart it. I can get it started by removing the injector caps, cranking and starting the engine till the fuel burns out of the cylinders then reattaching the injector caps and trying to start the engine. Usually it floods again and I just try starting it with two or three injectors firing, but that's a two person project, someone to crank the engine while I reattach the injector caps.

WHEN THE ENGINE STARTS IT RUNS PERFECTLY, NOT RICH. My thinking is that there may be a problem with the computer since the flooding seems only to occur when I am cranking the engine and stops once the engine runs. If it was a bad injector, bad ground wire, bad coolant temp sensor or bad air intake sensor, it seems the problem should continue after the engine is running. My thinking is there is something in the computer that tells the engine to be rich at cranking.

Anybody have any ideas.


TJ Hannink Member posted January 06, 2003 06:51 PM

re: Rich start condition - Fuel Injection

Sound like the Temperature 2 sensor is sending bad coolant temperature info to the ECU. Check your manual for location of the sensor, in my '87 camper it is located in the thermostat housing, I'm not sure where it is in your van.

The manual has a test procedure for the sensor, but if yours looks like its original, it wouldn't hurt to replace it as preventive maintenance.

You might also check your coil wire to make sure it is in good shape, a bad wire can cause similar problems.

Good luck,

TJ Hannink
Goldibox - 1987 Vanagon Camper, Wolfsburg Edition
Winter Park, Florida [Vanagon] Album


New member
after much searching, i am electing to post here.
'85 westy, 115K miles FI
Bentley owner
I will give you the symptoms.

Starting the engine stone cold, the engine idles fine. When I travel long distances (100mi) or short (5mi) and turn off the engine. Let it sit for 5 - 20 min...when i restart the engine, at idle rpms dive and climb. almost stalling. THIS condition will stay dropping from 1,000rpm to near zero (almost stalling) until I accelerate (in gear). As I accelerate, the engine bogs down (no response to depressing gas pedal) until it finally begins to accelerate. Once this "trouble area" is over...the westy accelerates fine and idles perfectly.

Today i changed the fuel filter just for kicks. I am not sure where to go from here. My mechanic is not sure where to go. He says as long as it doesnt leave me stranded...then let it could be very expensive trying to track down the culprit. This bothers me because it is a dangerous situation trying to pull out of a parking lot without acceleration in Atlanta.

The thing that baffles me, remains how the problem completely vanishes NOT after idling, but after driving the car the first few 100 feet (after some hesitation and bogging down). It is almost as if some pressure is lost in the fuel line when the car sits...and then it takes a bit of pressure to get the fuel moving again.

Any of your expertise would be greatly appreciated.


Capt. Mike

That it starts fine cold indicates the FI and fuel system are probably working fine (and why the change of fuel filter had no effect).

Once the engine is started, other sensors come into play. See the "Injection & Sensor idle problem" thread and the "Engine misses, surges . . ." thread. Possible causes are the Temp Sensor sending an improper signal as the engine warms, or the throttle/idle switch not changing over. Test of both is described in the Bentley.


New member
I will try out those tests per the Bentley. I will let you know what shakes out. My mechanic said something that I want to check with you. He said my '85 westy doesn't have an idle stabilizer. Does he speak the truth? tp

Capt. Mike

An '85 should be Digijet. Tell him to read page 24.18 where it describes the various tests with & without the idle stabilizer connected. The auxiliary air regulator perfromed most of the idle correction functions. Later versions (24.24b) used idle speed boost valves to augment that idle corrections. Fig 28-381 on 24.29 shows the idle stabilizer control unit connection of the narness, 24.31. Early models used a multi-switch to control full throttle/decel/idle; later models a single switch.

Capt. Mike

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CW Junior Member posted April 27, 2003 06:24 PM

We have been struggling with a 1980 Westy air cooled. Don't know what the problem is. Will run very rough a few moments then die. VERY rich but acts like it is a electrical issue one moment, the next a fuel supply problem.Virtually everything replaced. The dealer gave up on this one last summer. Need help!

Garyo Member posted April 27, 2003 08:56 PM

Any chance of putting your computer into another '80 to see if the problems follow? That way you'd be confirming if your computer is on the fritz or not. Plus it would be safer than putting someone else's computer in your Westy and end up frying it. Sort of trial and error without any electronic expense!

CW Junior Member posted April 27, 2003 09:29 PM

Already tried 2 different computers without any luck. Of course both might be bad. The Bentley trouble shoot seems to point to a bad ECU sometimes = no flickering current to the fuel injectors. Then other times it seems to point to a break in a wire leading into the double relay= no voltage on the center wire going into the 4 resistor unit.Brand new: Bosch injectors, air flow meter, fuel pump & hoses, double relay, distributor, spark plugs & wires, electrical fuel inj. plugs, engine temp sender, even replaced entire engine wiring harness, etc. Really very elusive problem. Thanks for the suggestion... if you think of anything else please let me know.


New member
Rough idle when cold

I have a 1982 air cooled Westy with 15,000 miles on a remanufactured engine. When the engine is cold it fires up immediately, but the idle fluctuates and after 30 seconds or so it dies. I can prevent it from stalling out by giving it gas. After it dies it fires right up again, but the idle continues to fluctuate, coming very close to stalling out. Once the engine is warmed up it runs and starts great.

Here is what I have checked:
-new ignition wires
-new spark plugs
-new distributor
-new points
-point gap and timing are right on
-cold start valve does not leak (Bentley 24.6)
-thermo-time switch is good (Bentley 24.6)
-temp II sensor new
-deceleration valve is good (Bentley 24.7)
-Auxillary air valve checks out electrically (Bentley 24.9)
-Auxillary air valve fails 5 minute ignition test (Bentley 24.9) (Even after 30 minutes with ignition on, the valve does not close). However, after 10-15 minutes of driving around town the valve closes.
-I currently have the EGR valve disconnected from the throttle body while I figure this out. However, it closes tight and does not leak any exaust gas into the air plenum. I plan on getting this hooked up after I take care of the idle problem.
-All vacuum hoses have been replaced. Rubber boot running from Air flow meter to throttle body is good. Rubber elbow on the AAR is new. Have NOT checked the condition of the seals on the fuel injectors.
-Air Flow Meter checks electrically (Bentley 24.9). However temp sensor I (in air flow meter) checked out at 1418 Ohms at 75F compared to specs of 2300-2700 Ohms at 68F according to Bentley. Not sure if this is enough of a deviation to worry about.
-Tried to check the system at the ECU control unit plug, but could not find any numbers on the plug corresponding to the terminal numbers in Bentley. (???)

Ok, I think that's it. Any help would be appreciated.

Jake B
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Capt. Mike

Your symptoms point out to a problem in the cold-start and warm-up sequence. Last, first, Bentley 24.20 & 24.21 show the numbering sequence for the Digijet FI; the AFC should follow the same pattern. The diagram in the late Type II manual (also AFC FI) shows this same pattern, Section 10-3, Fig 3.1 & Fig 4-23. The numbers are usually on the box, not the plug, but I've seen both. They can be tiny and faint. This is an important set of tests so can't be 'worked around' easily.

Your comprehensive diagnosis list doesn't show check of the Cold start valve for function, 24.5, Fig. 2. That you start cold OK, but then must keep the engine running with more throttle (= more air) is an indication your are too rich beyond the first start seconds. That it doesn't leak when "off" (Fig. 3) isn't a test that it's injecting at a proper rate when on.

[FI does a funny start sequence. It basically injects more fuel to make the ECU order the aux. air regulator to inject more air, thus leaning out excessive richness. Apparently the control of air is more effective or accurate than the ability to richen slightly with fuel alone. Or messes causes pollution that can't be controlled by just fuel.]

The auxiliary air valve, whose purpose is to enhance the air supply when cold (see above), has failed (by your tests). Good place to start! I believe the part number is 022-906-045P but check with a dealer first for upgrades. I have that note in my shop manual so it indicates I've run into something with one in the foggy past.

At the end of the Temp I sensor range, the ohms get pretty big and hard to measure. I'd consider that the least likely if it's showing good readings at all it's other settings.


New member

Thanks for the input Capt. Mike. I have followed up on your recommendations.

-I have checked the cold start valve for function. I do not have a fuel pressure gauge so I could not do the test in Bentley (24.5). I removed the cold start valve from the air distributor, left the electrical connection in place, and turned the vehicle over. Gas sprayed out of the valve in an even conical shape for about 5 seconds. I also ran the diagnostic in Bentley 24.5, but without the pressure gauge. I removed the valve from the air distributor and operated the fuel pump to build up pressure in the fuel system. I then jumped the valve and watched gas spray out until the fuel pressure dropped. I think these tests show that the cold start valve is working properly.

-I tested the FI system at the ECU plug (Bentley 24.15). Only abnormal reading was between terminal #1 and a ground. Resistance was infinite when the white wire was connected to the coil (consistent with specs). Resistance was 30 Ohms when the white wire was connected to a ground (specs are for 0 Ohms). I am not sure how to rectify this. Any suggestions.

-I could not figure out how to test the Auxiliary air regulator and wires through the ECU plug (Bentley 24.15). Bentley says to measure the resistance between #34 on the ECU plug and #37 on the double relay. The terminals on the double relay are labeled 85,88a, 86b, 88b, and 88c. The terminals on the double relay plug are labeled 1-9. I could not find terminal #37. (???)

-I have a new auxiliary air valve on order. I'll give an update after I have installed it.



New member

1982 Air Cooled Westy

This message is a follow up to the three above. I just got the new Auxillary Air Valve (AAR) and installed it today. I checked it out according Bentley 24.9. It failed the five minute ignition test, just like the old one did. I measured 12 volts on the AAR plug when the ignition is on. So, the AAR is getting the signal telling it to close, but it is not closing (even after 45 minutes with the ignition on). It seems highly unlikely that the brand new AAR is defective. Any ideas before I send it back for a new one.




New member

1982 air cooled Westy

This message is a follow up to the three above. I beleive that when testing the Auxillary Air Valve according to Bentley 24.9 the engine must be running. With the ignition on and the engine off, the brand new auxillary air valve does not close. With the engine running and the ignition on (obviously) it closes within four minutes. Installation of the new auxillary air valve helped with the cold start problems outlined above. Now the motor only dies after the first start when cold. The second time I start it up the idle is a little rough, but it doesn't die. The idle smoothes out considerably as the engine warms up.

-This weekend I checked the fuel delivery side of the system. Fuel injectors do not leak and have a good spray pattern. I replaced the fuel injector seals while I was at it. Fuel pump delivery rate is right on. Replaced the fuel filter.

-I bought a dwell/tach meter and a timing light. Turns out the dwell and timing were off. I corrected this. While this rectified other performance issues, my cold start symptoms were not affected.

-I have now thoroughly diagnosed the igniton system, fuel injection system, and fuel delivery system and cannot solve this problem. Through a process of elimination I am beginning to suspect the ECU. Anyone out there have a good one they could lend me to test this idea? Any other suggestions are welcome.