85 Vanagon Digijet

[Lanval]

Sheeeesh.... it's always something. OK, here's where were at:

I got pretty much everything off, allowing some instruction as to WHY I'm doing this (beyond the original problem of bad ecu).

Here's the original plenum / FPR versus the replacements:



Not pretty, eh?

The old runners:



and the new:



Removal of these items revealed an unpleasant rattiness that begs to be cleaned:





Yum.

Now cleaned up:



But this leaves a couple of questions, and a problem. First the questions:

Colin, this wire is pretty well chewed. Can this be replaced? It seems like it's really stuck in the engine block (you can see the black end in the back ground)? Otherwise, I'll just cut the chewed segment out, and replace it with wire. Not sure how I'm going to get a soldering iron over there, but that's the plan.



That same wire was run over to the plenum, where a plug was hanging, and was NOT plugged into anything. here's the three-prong end. I don't see any plug for it on the new harness. What's supposed to happen with this?



And now for the problem. You may remember Colin, an odd brown wire that was coming out from underneath the A/C mount; it had been cut, and I was not sure what it was for, or what it connected to. Here's the problem. in order to remove the A/C mount, I need to get to an allen bolt under the round thing which hangs off the distributor. Here's a pic that is as good as I could get in late afternoon light, with my phone:



Mindful of your comment to Nathanael about how pulling the distributor can allow a washer to drop into the engine, requiring pulling the engine apart, I am extremely reluctant to pull the dist. without you.

The distributor doesn't have the same bolt that allows me to move it in place as on my old air cooled, so I'm at an impasse as to how to get to the last allen bolt.

I need to remove that stupid bracket to solve the mystery of the brown wire definitively. I feel strongly that it runs to some kind of sensor/connector which is down on the block behind the flywheel, but I would prefer to know rather than guess. Suggestions?

Best,

Lanval the increasingly capable, fearless engine rehabilitator

[satchmo]

I ain't Colin, of course, but I can clue you in on a couple of things.

That chewed up wire with the three pin plug is a flywheel sensor. I think it was used by VW as a sensor for timing and tune-ups, and as part of the plug-in diagnostic system. It is completely superfluous for the home tuner and most folks just cut it off right at the end of the plug that is stuck in the back of the case.

Don't fear removing the distributor. Just mark its current position so you can get it back in fairly close to the original position (you WILL be re-timing the engine anyway once you get it running again, yes?) and put a paper towel down the hole so you don't drop anything in there (that wouldn't be the end of the world anyway since the distributor drive gear is still in there and prevents items from falling into the case).

Onward.

Tim

[Amskeptic]

Errrr, what my deputy said.
Colin:Patio.MintJulepsonthe,

[satchmo]

Another thought on the brown wire under the A/C mount you are chasing: On my 2.1, there are TWO oil pressure sensors. One is between the push-rod tubes of cylinders 3 and 4. The other is hidden behind the crankshaft pulley on the rear (rear as in nearer to the bumper) of the engine. Both have a single brown wire running to them from the front left engine compartment wall. Mine had the brown wire to the rear pressure sensor snaking underneath the A/C mounting bracket, just like yours. Now, you mentioned you had a 2.1 engine rather than the 1.9, so maybe you also have this second oil pressure sensor too. Just a thought.

Tim

[Amskeptic]

Another thought on the brown wire under the A/C mount you are chasing: On my 2.1, there are TWO oil pressure sensors. One is between the push-rod tubes of cylinders 3 and 4. The other is hidden behind the crankshaft pulley on the rear (rear as in nearer to the bumper) of the engine. Both have a single brown wire running to them from the front left engine compartment wall. Mine had the brown wire to the rear pressure sensor snaking underneath the A/C mounting bracket, just like yours. Now, you mentioned you had a 2.1 engine rather than the 1.9, so maybe you also have this second oil pressure sensor too. Just a thought.

Tim

We were up on that dual sensor deal. I, I, I, don't LET no VW engine start with no SENSORS hooked-up, um hmmm.
Colin

[Lanval]

Colin,

Edited original post:

Satchmo is right. Although you did correctly hook up the .3 bar oil switch, if you refer to 17.7 of the Bentley, you'll see there is a second oil pressure switch which is set at .9 bar, placed in the location of the oil pump. The Bentley notes this switch is from 86 on.

I suspect that Satchmo is right, though I'm still going to rescue that wire, and if necessary, install a separate gauge, and possibly a new switch. I wonder, though, if I can find a gauge set for such low measurements....?

In any event, I suspect two things:
1. The 85 harness won't have a connector for that switch
2. Even if I did hook it up, the current gauge won't be set to do anything with the info.

From the Van Cafe website on oil issues (original link is http://www.van-cafe.com/home/van/page_15

Quote:

"Faulty/incorrect oil pressure sending units:

It is quite common for WBX (and other) engines to be fitted with the incorrect oil pressure sending switches. These are the switches that detect low oil pressure, and cause the idiot light and buzzer to activate. On the WBX (1986 and later), there are two sending units, one for lower RPMs (below 2,000), and one for higher RPMs (above 2,000).

The lower RPM switch is located on the driver's side of the engine, between the pushrod tubes for cylinders 3 and 4. To access this one, you will need to remove the engine tin, which means a couple of exhaust nuts as well. Which means you'll probably strip at least one of them, so proceed carefully. The sender should be 0.3 bar/4.4 psi, and is light brown in color. If the incorrect sender (a higher pressure unit) is fitted to the engine, it will give a false warning when pressure drops below its allowed range. Note that the sender will state a range of pressures, not an exact pressure. The range should include the numbers stated above.

The higher RPM switch is located near the crankshaft pulley. This one is a little trickier to get to, but if you remove a couple of belts, and push the exhaust shield out of the way, you should be able to get a socket on it. It helps to use a reducer on your ratchet to make a 1" extension. This sender should be 0.9 bar/13.1 psi, and grey in color. On my most recent vanagon, I had a Canadian VW factory rebuilt engine, and this sender was the blue one, rated for roughly double the pressure of the grey one. No wonder I was getting a light and buzzer!!"

Leaves me wondering what to do with it...


I'll think about it. Parts did not arrive today, so I'll take some time tomorrow to remove the dist, clean up that area and get ready for Monday install time.

Thanks guys!

ML

Best,

L

[Lanval]

Engine is back together again. Started up first time, but there are issues. With the first start, the engine was revving high, around 1500 to 2000 RPM. If I put it in gear, it tried very hard to stay in those RPM ranges. If I put it in gear and used the brakes to slow the RPM, it begin to struggle, and died as the RPMS dropped to around 1000.

So I started it up and drove it in a circle back to my parking spot. Unplugged the two idle stabilizers and plugged them into one another per the Bentley. Then with the dizzy loose, I tried to adjust the timing to the correct location. According to Bentley and Digijet, the correct timing procedure is to bypass the idle stabilizer unit (which I did by plugging the plugs together), leave the vacuum hoses connected, and adjust the timing to 5 +/- 1 degree ATDC.

If I attempt to get it there, it is so lopey it barely runs. If I move the dizzy back, it runs OK but at high RPMs. I'm wondering if this is a Throttle body issue, as it seemed to me in playing with the TB, it had a major effect on how the engine was running. If the idle switch is open, the engine ran OK, but with high RPMs. Close the switch and it got lopey, usually dying after loping along for a few minutes. I'll try switching the old TB back in, just to see if that makes a difference.

One thing that bothers me. The setting of the dizzy to get it at 5 deg ATDC, and the illustration that shwos it in the correct location in the Bentley, are completely at odds with where the dizzy was when running. Remember that I couldn't get to a screw in the mount for the A/C? That's because the thingy attached to the dizzy (vacuum canister?) was blocking the bolt. In the location necessary for the dizzy, the canister is completely out of the way of that bolt. Which means in its original form, the dizzy was in a totally different spot...

Thoughts?

[satchmo]

Again, I'm not going to be much help, but I have had experience with a distributor that didn't want to play nicely with the engine. I found out it wasn't the distributor's fault. It was the fault of the person who installed the distributor drive gear incorrectly.

To make sure the dist. drive gear is not a problem for you, put the engine at TDC for piston number one. Take the distributor out of its hole and take a look down in there. You will see a slightly off center slot in the drive gear. It should be at an angle from the center line of the case that is consistent with the specification in Bentley (which I no longer have at my disposal which means you will have to look it up). If it meets spec, you can check that off your list of reasons why the distributor (and the vacuum can) seem to be in the wrong position. If the slot isn't at the correct angle, you need a distributor drive gear puller to get it out and then reinsert it at the correct angle. It might take several attempts since the drive gear rotates a bit as it drops into position and you can easily be off a gear tooth or two. That may be what happened to the original builder.

Good luck, Tim

[Amskeptic]

Engine is back together again.
The setting of the dizzy to get it at 5 deg ATDC at odds with where the dizzy was when running.
Thoughts?

The 5* ATDC presumes a running engine with a functional vacuum retard.
You can only set it to 5* ATDC with the engine running.

Insane lope and inability to get the engine to stop drifting around is usually
just a dumb exceeded parameter freaking out the ECU.
But your fuel pump is grounding properly, yaah?

Colin

[Lanval]

When I turn the ignition on, the fuel pump runs for a second or two then stops. This freaks me out, since I feel like it's not working, but in fact, that's what it's supposed to do, isn't it?

I will clean and check the ground from the fuel pump to the chassis for continuity (I will probably replace it, in fact). I will clean the ground point on the firewall under the coil.

I will replace the TB with the known working TB, which, while rat-peed upon, seemed to work (I'm wondering if the switches are causing some of the problem, or possibly a sticky/bad butterfly valve).

update as soon as I can.

L

Also, what says the maestro to Tim's thoughts? The rotor in the dizzy seems to line up correctly per the Bentley when the TDC marker is at the case split. The Bentley refers to a mark on the dizzy body, which as you may remember, we couldn't find/see. So I had to eyeball it in per the Bentley.

I may try and get some video with sound posted on youtube so you can see it.

L

[satchmo]

In my van, you hear the fuel pump run pretty loudly until the pressure in the system comes up, then it gets pretty quiet.

[Lanval]

Tim,

Which makes me wonder if there's another, different problem ~ the ignition switch. I've read many times this can cause a problem...

Still, I have to think that if the system ran OK under the old setup, with the crappy wiring and all, hotwired, then it shouldn't miraculously be a new problem.

I'm off to get a new ground strap as well as some sandpaper to clean groundwires and points with. We'll see.

L.

[Lanval]

Tim,

Which makes me wonder if there's another, different problem ~ the ignition switch. I've read many times this can cause a problem...

Still, I have to think that if the system ran OK under the old setup, with the crappy wiring and all, hotwired, then it shouldn't miraculously be a new problem.

I'm off to get a new ground strap as well as some sandpaper to clean groundwires and points with. We'll see.

L.

[satchmo]

Tim,


I'm off to get a new ground strap as well as some sandpaper to clean groundwires and points with. We'll see.

L.

Thought you attended to this a long time ago?

[Lanval]

No, because strictly speaking, it wasn't necessary. Once I hotwired the relay, it was self-evident that everything else in the electrical system is OK. I only did this today because Colin won't keep quiet about it. Checking the grounds is only meaningful if it NEVER works. If it sometimes works and sometimes doesn't, and the item changing isn't directly connected to the ground, then the ground is OK.

However, since Colin is an absolutist in this regard, I did it today simply so we can get past it. As of now:

New ground strap from engine to driver's side head. all ground rings on firewall under the coil and on the driver's side head are cleaned with a file until shiny. All grounds are connected to body/head with new steel bolts.

The ground to the chassis for the fuel pump has been replaced. New 14g. wire with new female connector. On the chassis side, A new ground ring, and the ground point was sanded to bare metal. New steel screw w/no oxidation fastening the chassis side.

Replaced the vacuum line from plenum to fuel pressure regulator.

They only had one ground strap at the auto shop. I will make a new one from 6 gauge wire for the ground strap that connects to the transmission. I don't know where it is, but I'll replace just so it's out of the picture.

*************************

Colin, since you commented that the ability to set the idle at 5 Deg ATDC hinges upon proper vacuum retard ability, are you inclined to look at vacuum leaks? I did a cursory check on obvious spots with my new bottle of carb cleaner, but didn't see any effect.

After replacing/fixing various ground points and the vacuum line today, the engine runs exactly the same. I can sub in known good parts (I use that term loosely) since I have the original Fuel Pressure Regulator and Throttle Body.

L.