Eurovan 2.5L Check Engine Light Flicker,then stall, no codes

[bmmtraker]

Hello all Eurovan fans,
I have for long avoided the electrical issues of the vw, but I believe my luck has run out.

1995 Eurovan Camper
2.5L Manual Transmission

Symptoms: Flickering check engine light, bucking, stalling. Not necessarily when under load, has even flickered when car not running

I have a flickering check engine light issue that has been present for the past 4 weeks I have been having an intermittent problem with my bus and a flickering check engine light. It will randomly start flickering and typically (but not always) my engine response will start to be erratic. Like: no response to gas, very bogged down engine power, bucking (from what almost feels like a misfire or running out of gas), etc. The bucking is the painful part where I feel bad each time it goes through these episodes, doesn't feel healthy.
In about 50% of cases the engine will eventually stall. Sometimes during this stall the check engine light will continue to flicker, turn off or stay on. In some cases, I can prevent it from stalling by pushing in the clutch. In cases once it has stalled, it either starts right back up or takes 1-2 key turns for it to turn over. In one case, I had trouble starting it from cold. In another case, the van had stalled and the check engine light continued to flicker on and off (you can hear a solenoid in the back tweaking).

When the issue first started, we did read the codes and got the following (however the codes had not been cleared in quite some time):
-Intake Manifold Pressure Sensor - no signal
-O2 Sensor correction at limit
-Secondary air system faulty
-EGR system, signal shorted to plus.

After driving around for a week and having the issue occur multiple times (a few with the check engine light remaining on for an extended period of time) There were no major codes that came back...

It very much feels like a computer issue. However jumping to replacing an ECM (023 906 024) is no easy task (to find).

Any help is appreciated
_________________
Burlington, VT Area
1995 Eurovan Camper
2.5L 5cyl 5 speed

[61Scout]

Howdy. So.... What diagnostic work has been done?

What is the state of your battery, cables and alternator? Have you checked for loose connections? Pulled them apart to check for corrosion? Looked over the harness for rubbing? Do you have anything aftermarket tied into the system? Alarm or remote start? Did this problem occur in conjunction with any recent service done (by you or a shop) on the vehicle?

You've done a good job tracking the problem, and do continue to keep track of when it fails and what conditions are present. But we're all just guessing what's wrong at this point. Time to dig in and do some testing. Not many Eurovan owners around, but you might try sending out some PMs to those who do. I personally don't own one, but I hate seeing Eurovan threads fall into oblivion, so I thought I'd give you a bump.


-Kevin
_________________
1986 Westfalia Weekender Wolfsburg, RJE 2.3
1985 Tin Top, Subie 2.2 + 5MT
Floppy Mirrors no more: http://www.thesamba.com/vw/forum/viewtopic.php?t=653018&highlight=
Remove the front spindle nut with ease: https://www.thesamba.com/vw/forum/viewtopic.php?t=679567&highlight=
Remove the rear wheel bearing housing without messing with the big 46mm nut: https://www.thesamba.com/vw/forum/viewtopic.php?t=679507&highlight=

-Nec Spe, Nec Metu

[bmmtraker]

Thanks for the bump, it is difficult to get feedback as a Euro sometimes so I appreciate the effort!

This morning on the way in, completely lost engine power and ignition. Tried to drop the clutch (repeatedly) to start it back up, as it came to a stop, with no response. Waited for about 10 minutes after repeatedly trying to restart it with the key. Starter turns, feels like it is out of gas (bud definitely not) Eventually came back to life with a key turn.

-Battery is older - have checked for corrosion and loose connections on that
Did recently install two new electrical devices, not sure why I haven't worked backwards to uninstall and see if there is any fix from that but the install dates don't directly correlate to having issues.
- HID kit for the headlights (went on a 3K mile road trip with no issues after install)
- LED "fog" lights (tied directly to battery, issue started prior to hook up)
(both of these are never on during the issue)
-Took apart the distributor cap and cleaned contacts with a wire brush

- NO alarm, NO remote start
- No other major electrical add on's, most are added through the accessory battery
- Did not correlate to shop work

could try to post a video of the check engine light flicker if it would help...?
_________________
Burlington, VT Area
1995 Eurovan Camper
2.5L 5cyl 5 speed

[61Scout]

I'd start with some basic diagnostic work... here's a good primer on the subject: http://www.ericthecarguy.com/faq/solving-automotive-electrical-problems

Keep in mind however, your problem may not be of an electrical nature. 1995 I'm guessing is not obd2, in which case, most check engine lights at that point were primarily there for emissions failures. Check over your exhaust system with a fine tooth comb for any cracks, failed gaskets, and so forth. Check the intake for any leaks. Pull off the EGR valve and make sure it's working and not clogged up. There are number of things that need to be crossed off the list before even going after the electrical frankly.

If you don't own one already, I'd recommend purchasing a factory service manual. From there you can do some testing. I'd also check for obvious things... loose connections, busted vacuum hoses, corroded grounds, etc. I'd pull the spark plugs and take a fuel pressure reading also. Now is also a good time to cross out easy maintenance like the fuel filter, dist cap, spark plugs/wires, etc.

You'll need some values to help sort out the issue. Without knowing what these values are... for example, what the specific fuel pressure psi is... well, let's just say it makes it especially difficult to help over the computer. Pictures and the results of diagnostic tests will be the best information you can post up here in terms of reaching out for help.

The service manual should provide you with the specifications, at which point you can verify that the fuel psi you're seeing on your gauge is what the vehicle wants. It should also have a wiring schematic which can help track down your issue. Take a good look at those codes and see how they are related. Do they share a common power or ground? Are they related at all?

Replacing parts without proper diagnosis and a reason to replace said part is time consuming, ineffective and often expensive. Patience is the key, cutting corners on diagnostic work never pays.


-Kevin
_________________
1986 Westfalia Weekender Wolfsburg, RJE 2.3
1985 Tin Top, Subie 2.2 + 5MT
Floppy Mirrors no more: http://www.thesamba.com/vw/forum/viewtopic.php?t=653018&highlight=
Remove the front spindle nut with ease: https://www.thesamba.com/vw/forum/viewtopic.php?t=679567&highlight=
Remove the rear wheel bearing housing without messing with the big 46mm nut: https://www.thesamba.com/vw/forum/viewtopic.php?t=679507&highlight=

-Nec Spe, Nec Metu

[bmmtraker]

Update:

My '95 Eurovan Camper 5 Speed has had an issue that dates back about 5 months. It started with the following symptom:


Link


It all started with an intermittent check engine light flicker. It would occur when the van was running or not running, idle or at higher speeds, flat road or up hills, warmed up or cold. The check engine light would flicker (like in the 1st video) and if the van was running it would, only sometime, cause the van to completely lose power (similar to the feeling of running out of gas, fuel line pressure is in spec) while the check engine light flickered on. I did also notice the sound of the #30 ECM relay clicking on/off. Sometimes the flicker would persist until I was stuck on the side of the road and other times it would go away for a few minutes to several days. I found that at times, I could pull the #30 ECM relay and it would prevent the van from stalling out when the check engine light was flickering, however with my foot on the gas, could still notice a severe loss of power as it flickered.

After replacing many worn vacuum lines and the EGR solenoid, the issue went away for about 2k miles, then returned... Then we replaced practically all of the vacuum lines, the ignition rotor, cap, wires and plugs as well as replaced the catalytic converter. Issue still persisted. Then we replaced the ignition coil and feed wire after noticing a weak spark. This then caused that issue (1st video) to go dormant but fruited the new issue immediately seen in the 2nd video:


Link


As shown in the video, at idle or while driving, once the van was warmed up, it would rev up and then drop to almost a stall and repeat this over and over. We checked the power to the coil pack and found that it was not receiving any ignition voltage during the drop to an almost stall. Also noticed was the charging circuit would go from a comfortable 13.5 volts to a scary 30-35 volts, this was seen during the van's cycle of revving up then almost stalling (in 2nd video).

After testing terminal 2 and 7 on the ECM, it was observed the output for the ignition coil (7?) was dropping out intermittently. So then, I resorted to send out my ECM for a rebuild and hope to hell it gets fixed. The repair house called yesterday to tell me that there was a processor in it that they cannot get a replacement for and that it will be returned to me unrepaired.

My garage seems to think that there is an issue with my charging system on my accessory battery side. That the solar panel or something else in the circuit was feeding an excessive voltage into my starter battery loop that may have caused my ECM to degrade over time. They observed that the solenoid which connects the two systems seems faulty.
Another forum yielded a similar issue with the #30 relay and thinks that it could lead to a fried ECU/ECM.

These are exciting time's in my life, where my fiance and I were planning to move into our van and travel with our business south, away from Vermont to head towards our dreams. Without much warning, the ticket to our freedom, Nigel (our van), decided to delay our plans.

I am sharing this in hopes that others will learn, but also desperate for any advice on how to move forward with this. I currently have a few calls out to other ECM rebuilders for references and to see if they can repair my ECM with the proper components.

I am curious to a few things.
-Do you (or the folks you spoke to) believe that if I am able to find a close version of the ECM, such as the 5wp4127, that it might perform nearly identical in the van?
-Any idea why pulling the #30 relay helps to temporarily band-aid the issue? My concern is that this is disabling the van's ability to shut down when it detects unsafe operating conditions.
- Do anyone know of anyone that has been able to flash the removable EPROM in these types of ECMs? Does anyone have a source for a blank EPROM? I would assume the most difficult part of this would be obtaining a map/program from another 5-speed ACU to flash it with...
-To possibly avoid another meltdown in the future of this ECM, can you help me to understand the specifics of a MegaSquirt System or other related system to redo the ignition system? I also would like to not have my ECM torn apart as a donor to support such a transition but I am desperate for a long term solution.


Any and all help and advice is appreciated!
Thanks everyone!
_________________
Burlington, VT Area
1995 Eurovan Camper
2.5L 5cyl 5 speed

[typetwotool]

This is just me pissing in the wind or shooting in the dark if you will but maybe the ignition switch could use an inspection? I know that they have been known to cause folks problems. I havnt taken the time to look at the wiring diagram but it might be a good component to add to the list of things to check.

Maybe the next time it starts acting up, reach down and fiddle with the key, might get lucky?
_________________
Nathan

80 Vanagon
00 Eurovan
69 Karmann Ghia

[Abscate]

Ignition switch. See my thread on replacing on my 2002.

That was a tough job, hope your is easier.

People often jump to ECU (or ECM) as failure points but they rarely fail if they arent messed with.

The fact that the charging voltage is shooting up is related to either a bad diode on the alternator or a loose ground - either one will cause voltage spikes.

You are getting close to the problem.

Stop in Albany on the way through!! Summer house
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.ssS!

[gakali]

While I do not have much pre obd2 VW experience, I would be tracking down power supplies and double checking grounds. This vehicle being 20 years old now is ripe for faulty relays, ignitions switches, poor connections, and similar problems. I agree that intermittently faulty ecm's are not very common.

Issues like cracked solder joints come to mind.

I would think that an ecm damaged from high voltage would be permanently fried. If an ecm has a bad charging circuit it may be possible to install an external regulator and bypass computer control. Not a proper repair but I've seen it done several times - and if a replacement ecm is unavailable this may be worth considering, at least for test purposes. Of course I'm assuming here that your alternator is computer controlled.
_________________
Why do it? Because you can.

1999 Eurovan
2003 A4 Avant 1.8T Quattro
1992 W201 190e 2.3 Mercedes
2006 W220 S600 V12 Twin Turbo 5.5 Mercedes

[gain7095]

I'm having literally the exact same issue. I've replaced all plugs, wire, cap, distributor, then fuel pump. But it keeps coming back randomly, no correlation to why.

I have a 1995 vw Eurovan auto transmission but this is driving me mad. I was gonna go and try and check grounds etc to the ECU but I'm running out of ideas. I was also going to replace the relay number 30 and see if that helps.

Please let me know if you ever had any success figuring this out.

[eurovanpilot]

[subdewd]

Relay or maybe the coil