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Sun Feb 01, 2015 4:36 pm

Wildthings wrote: If your year model came with a dual vacuum/dual advance distributor and the retard can is bad (very likely) or the original dizzy has been replaced with a single vacuum/dual advance unit, you can not time your engine according to the specs in the book. It is best to always time it at full mechanical advance, which if I remember for a 1.9 is something like 30° BTDC at 3500+ rpms, hoses off.

Now that you mention it, a while back I was having an issue adjusting the timing. I was trying to set the idle speed at 850 rpm by adjusting the screw on the throttle body and it had no effect. This originally lead me to believe that I had a vacuum leak and that's why I replaced the vacuum lines, intake manifold gaskets, and manifold hoses.
I'm running out of day light because I live it the woods so maybe I'll try and double check the timing tomorrow. Do you have a link to a write up about this better procedure of timing?

Sun Feb 01, 2015 4:41 pm

512dude wrote: Could also be:

a) Bucking Vanagon Syndrome - if that is the case you'll need to check with a know good AFS/AFM unit (located just after the air filter); there is a modification with a capacitor you can look up

b) Idle Stabilization Control Unit - located behind the right tail light, it is easiest to check by plugging in a known good unit and test driving

c) Idle Stabilization Valve - located on top of the engine, check to see if it hums when the engine is running

d) Throttle Switches - you can test these with the engine not running and key turned off. Manually operate the throttle arm back at the engine and see if you hear a click just as you move the throttle on and off the idle or relaxed position. If not, then you should attempt to adjust it. The throttle switch must be adjusted correctly so that the idle stabilizer unit come on line when you are idling. If the throttle switch is adjusted correctly and the idle either hangs up at high rpms or the vehicle is prone to stalling, then one of those two components is likely at fault.
Here is a VanAgain write up:

Idle Problems with 83.5-85 Water Boxer 1.9l

Idle problems that the earlier 1.9l digijet vans can have.

Idle switch being properly adjusted. The 83.5-84 vans have two switches one for idle and the other for full throttle. These can be tested at the switch with an ohm meter. Basically you want to see zero resistance at the switch when it is in the closed position. The upper switch is for idle and the lower is for full throttle. If the idle switch isn't closing at idle position you can adjust a screw until the switch closes.

I have had the idle stabilizer unit that is on the firewall be the cause of a fluctating idle as well. This is a small plastic box that has two round plugs going into it and is mounted near the coil. Unplug the two plugs and plug them to each other (you need to do this to time the van properly). If the idle is steady then your idle stabilizer unit is probably bad. If the idle is still lumpy then you are probably looking at a vacuum leak.

If the switch is working properly and you are still having a bad idle then you are going to check your timing with a timing light. I like to set the timing to 7 degrees BTDC. I know the book says 5 degrees ATDC but I have found that the 1.9l Engine runs crappy at this setting. I have found you can safely advance the timing to the same setting as the 2.1l Vanagons with no ill effects. In fact usually it increases your horsepower and smooths out the idle. Then adjust your rpms down by turning the idle air screw (large slotted screw on the top of the throttle body) in a little. Count your turns so that you can put the screw back to where you had it originally if need to.

Next I would check your manifold pressure (vacuum) at idle. It should be around 15"Hg at idle and the needle should be steady (no vibrating or fluctuating). If your vacuum is low or the needle is vibrating then you probably have a valve issue that is causing your idle problem. Double check your valve adjustment. The Bentley manual is acutally wrong on the proper adjustment of valves. I normally set mine to zero lash (the adjustment screw is just touching the valve stem at TDC on each cylinder).

You want to be sure that you have no vacuum leaks in the intake system as this can cause unsteady idle in the 1.9l. You can get some starting fluid and while the van is running you can spray around the engine compartment at the intake hoses. If the idle goes up then you may have a leak in that area where you are spraying.

If the Air Flow Meter is worn out this can cause a poor idle. Usually this is more of a rough running at idle than a wildly swinging idle. The only way to really troubleshoot this is to swap in a known good AFM from another 1.9l Vanagon. If your is really old and has a lot of time on it and you have tried all of the other troubleshooting you might want to buy a rebuilt unit.

Finally the Temp II sensor for the fuel injection can throw things off. This sensor is located in the thermostat housing and has a blue plug on it. You can test this sensor with a chart from the Bentley manual and an ohm meter. If the sensor tests OK, I would test the ground for the sensor and the wiring to the ECU with an ohm meter as well. I have found that the wiring on the older vans is getting fatigued with age and can have bad spots in it. If you find a bad spot you should be able to cut it out and splice in a new piece of wire pretty easily.

http://www.thesamba.com/vw/forum/viewtopic.php?t=385381&start=0

Sun Feb 01, 2015 4:53 pm

kg0483 wrote: Just got back from another road test. I had found a used coil in the goody basket of used parts my uncle give me so I decided to toss it in the van and give it a whirl... same problem. :(

It's not coil - fire related. The fact that it run nice when cold says it something else. Cat converter condition?

Ok, unplug your temp sender (ECU-BLUE one) and plug the old one instead, loose not screwed into the thermostat housing. Have a drive.

Ben

Sun Feb 01, 2015 4:57 pm

Basic and safe timing position:

Sun Feb 01, 2015 5:12 pm

"Here is a list of what I have done to the van recently.
New fuel lines, Fuel tank re-seal kit (due to leaky gas tank), New fuel filter,"

Having seen this, the first thing that occurred to me is that you may be creating a vacuum in your gas tank due to possible incorrect installation. Try running with your gas tank cap removed or loosened.

Sun Feb 01, 2015 8:12 pm

tjet wrote: Try cleaning the AFM wiper. Radio shack sells a really good cleaner for rheostats & potentiometers

Just tried cleaning the AFM wiper with the cleaner from Radio Shack... No change. :x

Sun Feb 01, 2015 8:14 pm

Howesight wrote: "Here is a list of what I have done to the van recently.
New fuel lines, Fuel tank re-seal kit (due to leaky gas tank), New fuel filter,"

Having seen this, the first thing that occurred to me is that you may be creating a vacuum in your gas tank due to possible incorrect installation. Try running with your gas tank cap removed or loosened.

My mechanic had this same idea, I tried it with no luck.

Sun Feb 01, 2015 8:36 pm

Double check to confirm the coil primary wires are on the correct lugs & not swapped

Sun Feb 01, 2015 10:41 pm

I think I have a bad ECU. I was just checking the full throttle enrichment switch and it failed the test to check how many volts the switch connectors were receiving. Bentley says to run the test after the van is warmed up at idle for a few min then shut off the car but leave the ignition on. I should read 5 volts on my meter but I'm only getting 0.01 volts.

My second test was to check the continuity from terminal 4 of the ECU to the full throttle enrichment switch connectors (pass) 0.00 ohms.

Third test was to check the full throttle switch to the ground on the left cylinder head (pass) 0.00 ohms.

At this point the books says that if these test ok I should replace the ECU.

Thoughts? :?:

Sun Feb 01, 2015 11:11 pm

Worth a shot. Here's one for a good price.

http://www.thesamba.com/vw/classifieds/detail.php?id=1734496

Sun Feb 01, 2015 11:22 pm

tjet wrote: Worth a shot. Here's one for a good price.

http://www.thesamba.com/vw/classifieds/detail.php?id=1734496

Thanks for the link. Go Westy AKA (Go F***k Yourself) wants $429.95 plus
a $400 core charge for their 1.9l ECU... :shock: and If your core is not rebuildable, you will forfeit your core charge. WTF Possible $829.95 for a rebuilt ECU!?! :evil:

Mon Feb 02, 2015 12:47 am

I'm still not 100% it's the ECU. I swapped in another unit and it has the same running issue? That seems fishy to me. This is driving me nuts... This van has me chasing my own tail.

Mon Feb 02, 2015 1:55 am

Maybe you should regroup & start from scratch. This also might be helpfull

http://www.thesamba.com/vw/classifieds/detail.php?id=262969

Mon Feb 02, 2015 5:37 am

One of my 84's acted like this, 2nd one & me fairly new at trouble shooting. Finally it was where o2 plugs together, section going to ecu.. I assume u r aware this a shielded coax type wire & IF loose frayed shield wires touch the center i causes a rich condition & bog dn engine. Meter shield to center wire, should NEVER get a shorted reading, but u will geta resistance due to ecu ckts. Unplug ecu = infinite reading. Unplug vac hose to pressure reg, if u smell gas it's diafram is leaking. Mine was intermittent & a single strand of shield would touch center wire at times.

Mon Feb 02, 2015 7:52 am

kg0483 wrote: jfu057 wrote: I also have an 84 that had a very similar issue when I first first got it. The shop I purchased it from was nice enough to let me take it on a couple trips and then bring it back in and report any problems. They replaced the AFM at no charge, which fixed it for me.

There is a contact strip inside the AFM that wears out over time. I think this is what was causing my issue. Not sure why it presented like vanagon syndrome or whatever its called though. Maybe heating up the engine causes some minor movement inside the AFM.

Did they shop rebuild your old AFM some how are was it a brand new unit?
I did swap out the AFM with a spare that I had after the problem started just to see if the power loss remained. No luck. I guess it is possible that both meters are bad?

They did not rebuild it but it was a rebuilt AFM that they purchased I believe. Not sure where they got it, but Gowesty sells them. You might want to exhaust the rest of the possibilities first, these aren't exactly cheap.

There is a procedure on here somewhere for testing the AFM for a steady output throughout the contact strip with a multimeter. There are a few youtube videos as well.

As I said, you may find the issue elsewhere and I am far from a vanagon diagnostician but the AFM fixed my symptoms.

Mon Feb 02, 2015 5:39 pm

I suggest that you hang on to your ECU and your money.

The online detectives here now need a few more clues. Can you describe exactly what happens when the van gets up to heat and loses power?

For example, is there popping or backfiring in the intake?
Is the loss of power sudden and jerky or rather gradual?
Does the exhaust appear to be overly rich and blackish?
Will the van idle?
If it will idle, is the idle smooth or does it seem to have a miss on one cylinder?

Just to rule out particles in the fuel, can you drain some gas directly from the hose between the tank and the fuel pump and examine it in a clear glass?

Have you, by any chance, adjusted your valve lash recently? If not, fine. If you have, that may be a/the problem.

I note that you have cleaned your various grounds, but did you check them for resistance afterwards?

A couple more thoughts:
- fuel pumps can overheat, or lose pumping ability, but it is uncommon for them to do so repeatedly without failing.

- Can you keep tabs on your battery voltage while driving? If you are really getting an alternator charging problem that is intermittent, the drop in fuel pump output might (although I am skeptical) be enough to drop your fuel pressure low enough to cause the power loss.

We need more clues, although you have been very thorough in setting out what potential causes you have eliminated.

Mon Feb 02, 2015 6:54 pm

I know you changed the fuel filter but it sure sounds like a problem my son in laws van had. It would idle fine, then when he got it moving if he gave it the gas it would start to die unless he got off the pedal.

Once it sat for a while enough fuel got in the system for it to start again.

It got worse. Until it would only idle. I know you checked fuel pressure, but did you check fuel flow?

His had a pre filter and that was the one that was clogged badly. This was a result of going through a large mud puddle and his overflow tank was impaired with a hole.

Check fuel volume????

Just a thought? :roll:

Mon Feb 02, 2015 7:03 pm

cold it be a problem with the advance and the dist ?

are you saying that it only hiccups when you step on the gas hard ? does it do it every time in a way that you can make it occur ?

I do not know these motors that well but could it be the advance?

have you checked you fuel pump ? do you have sufficient pressure ?

Mon Feb 02, 2015 7:28 pm

Might also be a good idea to get in the wiring diagram in the bentley and start running through continuity checks in the alternator harness. That one can cause problems in the rest of the FI and ignition wiring

Mon Feb 02, 2015 7:42 pm

david2676 wrote: cold it be a problem with the advance and the dist ?

are you saying that it only hiccups when you step on the gas hard ? does it do it every time in a way that you can make it occur ?

I do not know these motors that well but could it be the advance?

have you checked you fuel pump ? do you have sufficient pressure ?

I think you nailed. The Bus seems to be fixed!!! :D