Vanagon Drivablity problems...

[MrLiMBO]

Hi Gang,

My 87 vanagon is experiencing some driveablity issues. Like thats a surprise.

Symptoms: Hi idle cold... 2500-3000 after warm up the idle is fine.

Runs poor cold. It acts like the choke is stuck on while cold. But of course its not carbureted. No power, skipping. During this time, I have to feather the throttle in order it get and keep the van moving.

But as soon as the O2 sensor warms up and kicks in it smooths out and runs decent enough. I know its the O2 sensor thats working because I unplugged it and it ran poorly and never got better until I plugged it back in. But it still isn't perfect. The engine has no power on the low end. But as soon as it hits 22-2400 RPMs the power smooths out and the van runs just fine. I could drive all day at highway speed without any problems.

Taking off at lights and climbing hills are as real PIA. I have to get the RPMS up and slip the clutch a bit to take off and climbo hills. Not good. for the clutch.

I've done a tune up. Plugs, cap, rotor, wires, air filter. I haven't done a fuel filter yet, but its on the list. Though I don't think its a fuel delivery problem. It has plenty of power in the upper RPM range.

I replaced the fuel pressure regulator thinking there was too much pressure it was fooding out at low end. No change.

I've replaced the coolant temp sensor. Twice. No change.

I've replaced the idle stabilizer because of the hi idle. No effect.

I don't have a spare AFM. So I haven't had a chance to check to see if thats the problem. I suppose I should get the book and my multimeter out and check it out.

I've got to read up on the double idle relay.

I've also checked out the green O2 sensor wire too. It checked out. I replaced the end just in case.

I did double check all the grounds and electrical connections at the various plugs for corrosion and poor connections. They all checked out fine. I cleaned a couple just to be sure.

I'm wondering what to do next. Or if anyone had any thoughts. Thanks.

I don't want to give up on the Fuel injection. For the most part, I've had years of trouble free service from all the vanagons I've owned. Its just got me stumped.

[MrLiMBO]

No replies??  No one has any ideas to pass along??  How bad is that!

I posted this to the LiMBO facebook page today...

Help, I'm at my wits end.  My 87 Vanagon is running like complete crap.  It starts fine cold, but while its warming up it has no power. Sputters and skips. If I feather the throttle I can get it to keep moving, but it takes about 5 minutes before it clears.  Even then, its not 100%.  It has no power on the low end.  Once it hits 22-2400 RPMS it runs ok.  Most times after its warm, it  starts real hard and a couple of times is wouldn't start.  I've checked out most of the major systems, temp sensors, AFM are supposedly in spec, according to the Bentley book. The book doesn't give any values for the AFM, but I did notice that the resistance is a bit irratic. It starts off at .5 and then as I move the flap, it jumps up to 1.1 and then it drops back down to .8 and then rises again from there.   I had some spare parts, so for giggles I changed the idle air regular, the fuel pressure regulator and the coolant temp sensor. No change. The only thing I really haven't been able to check is the idle air control unit.  That double relay behind the right tailight.   All the sensors check out.  I even unplugged the oxygen sensor and that made the van run poorly all the time.  So I figure thats working.   Help...

[Vanagonjr]

What about the 02 sensor?  Just a guess

[MrLiMBO]

I've ruled that out.  Its the only thing keeping the van running decent enough to continue to drive it.

[Vanagonjr]

I guess what I was thinking is that some O2 sensors have a heated circuit.  So sure unplugged van runs poorly.  But if the heating circuit is off, then the van may not run great until the exhaust heats up the O2 sensor.    I did not check to see if your van has a heated 02 sensor though.

If you have a known good ECU, then I do a pulg- & play with that - but I'd guess most problems with the ECU would be constant.

[MrLiMBO]

The plot thickens.. I headed over to Dale's Saturday and brought my ECU, AFM and idle control unit with me.   I plugged them into his 90 vanagon and everything seemed to run just fine.   The only thing I noticed was that the idle was surge when the ECU was plugged in.    

So now I'm thinking WTF? So I got a set of wires from Dale and put them on Sunday.   The van fired right up and seem to run just fine..could it have been the wires all along.  They were new last August and I've only got 12K miles on them.  Then, about 5 minutes later, I had to stop for a light and then when I took off, it started sputtering and running like crap all over again.  


That surging idle got me thinking...  When I was at Dale's I tried each part one at a time.  At the time, I thought everything is fine.  Aside from the surging idle.  But what I didn't think about until later was that Dale's van is an automatic.  I put the ECU in last.  After the engine was warmed up.  That and the fact the my engine will run decent once its warmed up and the engine RPMS are about 2400 RPMs or so.  I'm thinking the ECU is my problem.  

The automatic revs up to torque converter stall speed when you step on the gas and then engine speed increases from there.  On the vanagon torque converter stall speed is about 2500 RPMs.   If I slip the clutch enough while taking off, the van will take off perfectly.  If I drop in the clutch too fast, it bogs down and nearly stalls and it sputters and pops and then it clears out.  

So now I'm waiting for an ECU to come in the mail.  I should have borrowed Dale's spare then and there.  But at the time I thought my parts were good.  I'm also waiting on a fuel pressure gauge I order from Harbor Freight.  I replaced the fuel filter, which wasn't plugged.  I really don't think its the fuel pump. It runs well enough over 45 MPH or 2500 RPMS.  But I don't want to rule anything out without checking it.    I'm not giving up on the fuel injection just yet.   Keeping my fingers crossed.

[KingBee]

I have a similar "good weather blues" issue.
I have an '86 Weekender 2.1 standard.  I have owned this bus for 1 & 1/2 years and have been fixin' her up over that time.
She is my daily driver, so we drove all but the worst weather days into work during the winter, no problems.  
The first hot day, when it hit 85, she dies after 5 inutes of driving.  So the tinkering began.
I did the cheap and easy things first.  After checking the maintainance records I noticed she could use both a fuel filter( and O2 sensor see below).  changed the fuel filter, shee needed it.  Adjusted the throttle switch (whitch to my surprise was way out of whack).  Same engine cut out issue, then came the miltimeter tests for volts and resistance.  So far everything lookled good.
THEN ... One thing surfaced as a reoccuring issue.  

CLUE #1 - Everytime the temp sender hit 265Ohms resistance the engine cuts out.  
Per the Bently manual/chart 265 ohms is about 100degrees coolant temp.  Upon internet research I discovered 265ohms/100 degrees is the signal for the Digifant system to go from taking the temp sender signal as a 'cold start' injection mixture to using the O2 sensor signal for the injection mixture.  this is when I changed the O2 sensor.  Same engine cut out occured.
CLUE # 2 - the radiator fan kicks in exactly 3 times before the stall.  For about 10 seconds a time with a short 20second pause between each.
CLUE # 3 - what could possibly be another clue you may ask ... well ... I let the engine get to 100temp again, she cut out as expected, I unplugged the temp sender.  Started her up again no problem except I need to nudge the gas pedal as she will not idel she stalls at full idel position.
Clue # 4 - now I'm looking at the temp sender with a 'stink eye' expression and decide to check her out some more.  when the engine temp goes over 100 (I assume it's over as I ran it w/ the temp sender unplugged) I checked the resistance of the temp sender ... no signal.

OK ... you have the clues.  Replace the temp sender?  But if so, why does it stop having resistance at exactly the cut off point.  Is that normal because it dosn't have to go higher?

Any ideas are appreciated as I sit w/ my head in the engine compartment doing my best Yosimite Sam impression turning curse words into gibberish as the kids play in the diveway.

[KingBee]

I'm thinking about going to visit Fred in Barkhampstead at Mechanical Advantage if I can't get this fixed.  
I looked him up on Google and the pic from the 'street view' shows about 1 Eurovan, 6 Vanagons, 4 beetles, several other VW's and imports in the yard.  There was 1 review from a Vanagon owner with praise.  
He also seems like a 'fix it' not 'throw parts at it' kind of guy when I spoke with him on the phone.
Anyone ever use him?

[KingBee]

ARGH!!!   I replaced the temp sensor and still the same cut out  issue once the engine hit temp!  Although now the temp sender hits 300 ohms only now before the cut out.

By the way, I hope I didn't hijack the thread.  I was hopful by adding my experience it may give you ideas with whats going on with yours (and vicea versa).

Anyway .... Now I know it's not many things (AFM, O2, tempII, fuel relay) and more fingers point to the ECU.  I found a used one on the Samba I'm going to order.

Anyone near Rocky Hill CT w/ a working ECU I could borrow for 20-30 minutes to see if my assumption is correct?  Or ... I may have an extra ECU if that's not the problem lol !

[KingBee]

I seem to be talking to myself, but I know someone out there may get something from this.

When I ordered the O2 sensor from BusDepot, I discussed what was going on and the guy there gave me a tip.  Spray your vacumme lines with WD40 and run it.  If it runs for a while then gives you trouble later, check your lines as the WD40 would block a crack in the line for a while.  I found a loose vacmme hose going to the fuel regulator as well, gave it a squeeze and sprayed the hoses down.  

I can get down the road now.  After a little while, about 1 &1/2 hours later I started to get a little buccking when jamming on the gas pedal.  Looks like I'll be changing my vacumme hoses this weekend.

By the way ... yes I AM kicking myself for not going over the hoses earlier.  Learn from my mistake.

I'll stop by later and let you fine readers know how things turned out!  Trying to make it to the Pre-dust-off campout in MA!!!!

[KingBee]

MrLimbo, on your issue, did you check your Throttle switch for adjustment?

Did the new ECU help?

[MrLiMBO]

MrLimbo, on your issue, did you check your Throttle switch for adjustment?

Did the new ECU help?

I've unplugged the switch with no change.

Still waiting on the ECU.  It might be home waiting now. Dale called me last night but I wasn't home so we didnt' get a chance to talk.

[KingBee]

You won't believe the outcome  .... it wasn't ANY of the usual items you might run into.  A brittle wire from the starter solenoid to the alternator.  I will tell the whole story in my next post in 24 hrs from this one.

[KingBee]

I took the Vanagon to Fred in Barkhampstead, he knew his stuff and we went through everything .... EVERYTHING.
Replaced just about every piece to determine the trouble.
ECU, coil, pump etc all checked out (at least that's good to know)
Then we did the 'shake the wire" test, then rocked the engine.
Rocking the engine recreated the thing we experienced while driving (a studder).  She only stuttered when torque from the engine was needed in generous amounts, up hill or even over bumpy roads.  
Found a frayed wire, respliced ....
When all was said and done she drove great ... for a day.  then, the same situation.  At least this time it's slightly different.

After hanging in the engine compartment with Fred for 6 hours getting a super crash course in Vanagon maintenance and how to diagnose the Vanagon Syndrome studder...  (FYI-I can rebuild a 1600 air w/ my eye's closed, so this just brought it all home for me.) ... I ran though the checks again and found my throttle switch (the little click switch under the throttle body) is waaaaaay temperamental.  Once in a while she gives an OMH resistance (3.3 to 8.  when the throttle should be open and the OHM should be at infinity.
My guess is since there is a signal from the throttle switch to the ECU of 'resistance' the ECU goes into deceleration mode due to it thinking there is no throttle being given.

In a nut shell, I'm looking for a throttle switch or even a throttle body that I'll take the switch off of.  Got one you'd part with?

This is what kept me from going to Shrewsbury for the Ward campout and the dust off.  My kids and I camped in the back yard as a consolation prize.

Please contact me of you have one.  
Signed,
Desperately Seeking Throttle Switch.

[MrLiMBO]

After much toil and swearing and one small fire (no fire, just kidding) I finally fix the van!!!   You'll never guess what it was.    FUEL PUMP.  It was a weak fuel pump.  I ordered and finally received a fuel pressure gauge kit from Harbor Freight.   Hooked the gauge up to the test port near the intake manifold and the gauge read 19 PSI.  Working pressure is 29-36.    Thanks to Dale and a loan of a used fuel pump, I then had 31 PSI!!  Drove the van around town and it drove likea new Vanagon!!  

You can't imagine what a relief it is to finally fix the darn thing.  Here is what I tested and replaced over the course of the last two months.

Cap
Rotor
wires
plugs
fuel filter
air filter
coil (used)
fuel pressure regulator (used)
Aux air regulator  (used)


Tested the AFM.  Then drove to Dales to put my parts-AFM, ECU and Idle control relay- in his bus just to find out they were fine.  I then put in borrowed units from another members Vanagon to double check that theywere indeed fine.

Replace a few ends of the wiring harness including the green O2 sensor wire.  

Cleaned and replaced a couple of ground wires.

replaced vaccume lines and double checked the tightness of the intake manifold and fuel injectors.  

A new fuel pump is ordered and on its way....

I know have to get the van hooked up to a exhaust analizer to reset the AFM and idle.  I've fiddle with it enough that I'm sure its way out of whack!