# Frustrating Digifant II Random Stall or Cut-out Problem



## vanagonGTI (Jun 16, 2001)

I have an 1989 Golf with the 1.8L RV engine and Digifant II. Recently it has begun to cutout - literally shutdown the ignition - at random times when running at hwy speeds. In a recent 300 mile trip it occurred seven times often in two or three event clusters. Otherwise the engine runs smoothly, has plenty of power and starts easily. I have run through the Digifant resistance tests and all seems fine. Replaced plugs & cap, cleaned all ground contacts, cleaned distributor and coil contacts. Fuel pressure is at spec and replaced fuel filter. The symptoms are: 

1) At hwy speed engine dies, tach goes to zero, switched accessories remain on, battery voltage stays;Then turn ignition switch off, then back on and engine and tach recover and engine runs fine again. 

2) When the ignition has shut down (and the ignition switch remains in the on position), clutching while coasting to let the engine run down, then re-engaging the clutch does not restart the engine. 

3) During a stall or cut-out, if the clutch is left engaged and the ignition switch turned off then on, the engine power and tach indication comes back as before. 

4) Sometimes, the engine seems to miss, the car bucks accordingly, the tach goes to zero but them immediately recovers and runs cleanly as before. 

5) Cutout and stall never has been observed while idling, even during a 4 hour continuous idling test. 

6) Replaced ignition switch with no effect on the problem. 

7) Seems to occur only after the engine has reached operating temperature. Doesn't occur at cold or warm startup. 

8) Ignition shutdown only seems to effect engine power and tach reading, other dash gauges continue indicating, no change in battery voltage. 

Thoroughly frustrated. Any help, comments or suggestions greatly appreciated!


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## ps2375 (Aug 13, 2003)

Rip it out and install MegaSquirt. Troubleshooting will be soooo much easier.


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## srgtlord (Jun 4, 2010)

wow. I have a similar issue. Let me know if you figure anything out. If its a simple fix I might contemplate leaving the 8v engine in there.


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## ps2375 (Aug 13, 2003)

srgtlord said:


> wow. I have a similar issue. Let me know if you figure anything out. If its a simple fix I might contemplate leaving the 8v engine in there.


 It's not the motor, it's the management. And with no way to see what the ECU is seeing or not seeing, diagnostics will be hit 'n miss. Or more accurately, miss 'n maybe hit.


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## Fat Rabbit (Nov 18, 2001)

As I said to sgtlord. When my Digifant car did that I replaced the fuel pump relay and the ECU relay and the issue went away. He did that and his issue was not fixed. The situation sounds like something that drops out and then resets when the ignition is restarted. The other thing I would try is to snug in all of the connectors in back of the fuse and relay panel. It could be something like a loose wire or corroded connection. From time-to-time I have used a contact enhancer on Digifant electrical connections. I have also used electrical contact cleaner . You might take a good look at the air flow sensor connection. You can try replacing parts like the ECU, air flow sensor and fuse panel -- sometimes throwing parts at a problem works. You can also check the wiring for continuity. I've done some rewiring on Digifant cars because of broken or corroded wires. FR


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## vanagonGTI (Jun 16, 2001)

Thanks for the helpful suggestions! I had not thought of the relays since in my previous experience relays had been virtually invisible - never a failure problem. I will replace relays and test again. I have gone through the relay board connections and all were tight. I remade them but couldn't get in there to burnish the contacts. I did use the VW contact cleaner on the connectors before re-seating them. As far as throwing parts at the problem, I have accumulated space ECM's, distributors, AFM's, idle control valves and throttle switches - just hoped this was a specific enough problem that the solution might occur to someone more quickly. I'll report progress.


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## Fat Rabbit (Nov 18, 2001)

It once took me a year to diagnose an issue with an O2 sensor that was caused by a corroded wire. That issue would show up when the engine compartment was hot. When I tested the wire for continuity it always tested good but it was rotted off inside the plastic insulation. I never would have found the problem but one time when I disconnected the connector I felt some fluid on my hand that came from a hole inn the wire. Point being that sometimes things can be very tough to diagnose. 

You also might want to check that the fuse and relay panel is properly secured in its bracket. I had one car where the panel was not locked in place. That placed stress on the wires and caused them to become partially disconnected. 

I came to the conclusion that the issue I had was the Digifant relay because I could eliminate the issue by turning the car off and back on. FR


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## Bandwidth (Jul 8, 2009)

ps2375 said:


> Rip it out and install MegaSquirt. Troubleshooting will be soooo much easier.


 im having issues with mine also... im waiting for my relay board to come in for my MS2 settup )


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## vanagonGTI (Jun 16, 2001)

After searching the current posts and the archives, I have concluded that the key observation is the fact that when this cut-out or ignition interruption occurs I can leave the car in gear, turn the ignition switch off then on, and the engine powers back up immediately. The randomness of occurrences and the long time between the clustered events seems consistent with observations of the incipient failure of a relay. The lack of a stall or cut-out at idle might be related to the lower vibration levels at idle. The lack of stalling when cold could be a temperature sensitivity of the failure. The rapid drop of the tach suggests that this should be in the Hall sensor/ECM circuit. I have an Air/Fuel gauge monitoring the O2 sensor output. When running warm it is rapidly oscillating lean to rich, consistent with closed loop fuel control. When the tack shuts off with the ignition cut-out, the O2 gauge stops oscillating and indicates strong lean condition. As soon as the ignition resumes, it goes back to oscillating behavior. 

I've ordered the 165 906 381 relay and now await delivery and testing.


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## srgtlord (Jun 4, 2010)

I solved the problem!!! no more cutting out!!! lol 


 


This is actually a shot of the Cabriolet I have which also had the Digifant cut-out issue. Not anymore


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## vanagonGTI (Jun 16, 2001)

*Update!*

I finally received the relays and completed swapping out both the fuel pump and ECU power relays. Unfortunately, the problem persisted. All relay contacts were cleaned and remade in the process. During the testing, I found that just a slight motion on the key, when a stall or cutoff occurred, would restart the engine. I therefore went in and replaced the ignition switch. Again, the problem persists! Again small movements of the ignition key will restart the engine during a cutoff. 

Even more frustrated and open to any suggestions as to what to attack next!!


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## teutoned (Jul 29, 2008)

vanagonGTI said:


> I finally received the relays and completed swapping out both the fuel pump and ECU power relays. Unfortunately, the problem persisted. All relay contacts were cleaned and remade in the process. During the testing, I found that just a slight motion on the key, when a stall or cutoff occurred, would restart the engine. I therefore went in and replaced the ignition switch. Again, the problem persists! Again small movements of the ignition key will restart the engine during a cutoff.
> 
> Even more frustrated and open to any suggestions as to what to attack next!!


check ALL grounds. check ALL circuits relating to ignition switch. is "new" ignition switch OE, aftermarket, or used? is it possible but not probable that switch was bad out of box?


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## Fat Rabbit (Nov 18, 2001)

Your initial post stated that you replaced the ignition switch. The ignition switch would be the first place to check given your issue(s).

There are two parts to the ignition switch -- the electrical part (which is the part that usually goes bad) and the key part. For some reason the electrical part of the switch assembly is sensitive to heavy key fobs and those fobs cause it to fail. The electrical part is less than $/10 on line and is relatively easy to replace. I trust that is what you replaced.

Since the tip of the key blade extends into the electrical part of the ignition switch and presses a tab allowing the switch to turn (while the key operates the tumblers in the key part of the switch) you may want to try a different key. Your key may be worn to the extent that it moves enough to cause Circuit 15 (the "run" circuit) to drop out. PM me if you have questions. FR


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## vanagonGTI (Jun 16, 2001)

Sorry, should have said that I replaced the ignition switch again because of the sensitivity to small angle changes in key position. All testing has been done with the same key, so I will try another. All engine compartment grounds have been cleaned and rechecked. I have not gone over the interior or dash grounds as yet.


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## Fat Rabbit (Nov 18, 2001)

I'm thinking that there is enough slop in the key part of the ignition switch to cause the electrical part to drop out. Trying a different key is the first step. You may even want to have a new key cut so the key is crisp. A locksmith could likely cut a new key without even using the old one. I had one car where the daily use key got pretty worn but still worked. The issue could also be in the lock cylinder. If that is worn the key might rotate slightly and cause the electrical part to loose contact. You mentioned that the issue did not occur at idle with the car standing still. Road vibration could cause key rotation or movement of the electrical part of the switch. I'd also take a good look at the ignition switch electrical connector with special reference to Terminals 15 and 30. When you replaced the electrical part of the switch you made sure that the small screw that holds the switch in the steering column was in and tight -- correct? That screw is hard to reach. If it is loose or missing the switch might move slightly in the column and cause loss of contact. Just some thoughts..... FR


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## srgtlord (Jun 4, 2010)

Well I may have discovered the issue on my golf, there was a slight amount of carbon build up on the ignition rotor. I filed off the carbon and the cut-out issue seems to have disappeared. We will see if this is wishful thinking or not in good time.


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## vanagonGTI (Jun 16, 2001)

Did I say frustrating? Today I fired up the engine, tried two keys and manipulated the keys in the run position. The keys were pulled hard, pushed hard, wobbled in all directions and no stall/cut-out! Went in and checked the distributor, cap and rotor. Found carbon tracks and film coverage on the rotor! Cleaned the rotor and polished the end point of the rotor conductor, and added additional ground line from distributor to the valve cover common point. No effect! On the test run, again we had a few cut-outs. This time it took a full switch off and then on of the ignition switch to bring the engine back on. After studying the Bentley wiring diagrams again, we examined the several circuits supported by the ignition switch. As mentioned previously, when the engine cuts out, the tach goes to zero. But also, after today's testing, we know that the horn remains powered (during the cut-out) and the alternator light remains off. This suggests that the load reduction relay is not triggered off by the event and (possibly) that line 15 from the ignition switch has not gone to ground. The fuel and temperature gauges do not appear to move, but they move slowly anyway and I'm switching the ignition quickly to maintain traffic speed. 

It seems that this leaves the Hall sensor in the distributor, the Hall sensor ignition control unit and the ECU. An intermittent in the coil seems unlikely due to the quick response to the ignition switch. Likewise the Hall sensor in the distributor would seem unlikely for the same reason as well. On the other hand, flaky semiconductor operation would seem more plausible. Perhaps its time to swap ECU's.......


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## Fat Rabbit (Nov 18, 2001)

It only takes a momentary lapse in connection. Circuit 15 doesn't have to go to ground -- it only has to not complete for a second and things like relays will drop out. Don't neglect the Fuse and Relay Panel and the wiring that connects to it in the back. I sent a PM a week or so ago asking what fuse and relay panel your car had. 1989 was a transition year to CEII. That makes a difference in wiring diagrams etc. and may make a big difference in how the car is actually wired. Over the years I have done a lot of rewiring on Digifant cars. 

I think that you are correct in thinking about the ECU at this point. The engine rotating safety logic circuit was moved from the fuel pump relay to the ECU in Digifant. That circuit gets input from the coil and inputs into the ECU. It may also pass through the ICU. So those are items to look at. FR


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## Seax_Smith (Jun 1, 2007)

This is going to sound sort of stupid. 

Pull out the rain tray and go over the digi harness very carefully. If the harness is free to bounce around a little it can chaff and short out on the wiper assembly.

Had a car with a weird cut-out issue. Took a long, long time to find, it and it kept getting more and more frequent. One rainy day the car would cut out every time the wipers were on the back stroke at the exact same spot on the windshield, The car would cut out, wipers would move and the car would jolt as it pop started itself.


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## srgtlord (Jun 4, 2010)

It seems that all the digifant cars have these terrible cut out problems. Unfortunately there is no easy or quick fix. It literally could be anything electrical related. I have 2 digi powered vehicles. The first car I swapped a carbuerator setup onto. On my other digi powered car I pulled the motor out and its currently waiting for a 1.6l diesel transplant.


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## vw_fix (Jan 24, 2000)

My car used to do this so I was trying to remember what I did to fix it. I went through my parts orders and the thing that stands out is "Fuse and relay panel". I also remember replacing the fuel pump relay. 

Here's some other interesting reading:
http://www.benplace.com/vanagon_intermittent_syndrome.htm
http://www.ericthecarguy.com/forum/...51691-bosch-air-flow-meter-check-clean-fiddle


My most recent issue with losing power at speed was a broken fuel line inside the tank after the first pump.


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## Rusty Rabbits (Mar 24, 2015)

*cut out*

I know your talking about Digis, but I'm having the same problems with an '89 cabrio and it has CIS. On the highway at times it will shudder but keeps running, my problem happens mostly in town. 
You know when your having car problems and all you can catch is red lights and people in front of you dumbing around.
I've replaced key switches, control pressure regulator, alternator, plugs, cap and rotor, coil, hall sending unit, fuses and relays, checked and cleaned grounds. 
About the only thing I haven't replaced is the ECU. Looks like that's next.


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## Baker3j (Apr 21, 2020)

Has anyone figured out this problem?


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## matty kirk (Jul 2, 2007)

Based on the original post, it sounds a lot like "Vanagon syndrome." Google it. It was a predominantly a problem on Vanagons using the DigiJet system (hence the name). However, it also affected cars running Digifant EFI.

It was such a big deal VW invented a harness to fix it. 

Harness seen here...
https://www.vancafe.com/025906302AAFT-p/025906302aaft.htm


Just a thought.


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