It Lives!

I got injectors and a resistor pack from Troy (Thanks man!). I got `em in over the past couple nights (did you know 1/4" FI hose will fit if it`s heated up a bit?)

No difference. :(

This morning I hit the junkyard and there was a bug. All that was useful off it, unless a beat to crap case and swiss cheese pan are useful, was the distributor. I grabbed and for giggles tossed it the Guac. Holy smokes it worked!!!

My tach doesn`t peg and bounce anymore, the bus runs great, etc etc.

Something in the two distributors I have must be shorting out, or the ground strap while passing eyeball inspection has a weak spot. I`ll spend some more time checking those out later. Right now... ROAD TRIP!

Injectors and Resistors

I picked up some used injectors and resistor pack from another bus owner yesterday. On the way home I stopped by Target and picked up a box of snack size ziploc bags ($2) and a bottle of medical grade mineral oil ($1.52). I put each injector in a bag and filled it with the mineral oil, then put all the bags back in the Target bag.

They sat that way all day.

When I got home last evening, I installed the resistor pack and one injector, replacing one that I thought was suspect. I didn`t have time to do the rest, so I did a quick test drive. No joy. :( The replacement injector seems to be working nicely however.

I`ll update more tomorrow assuming I get to finish replacing the injectors tonight.

Troubleshooting Update

I finally got to do an AFM swap. No change. Same with the ECU.

The resistor pack tests perfect when cold. Run the engine for a little while and instead of 5-7 ohms of resistance per resistor, I get 3.4-ish on 3 of the 4 resistors. ARRRGGHH!!

I swapped resistor packs with Sykboy and the guac ran MUCH better. Still not perfect, but better. Although his resistor pack tested similarly.

It seems that the resistors were damaged by overvoltage for a long time.

I`ll be getting a new resistor pack and set of injectors. Here`s to hoping!

Fuel Injection Wiring Harness

Photos of the fuel injection harness. I labeled the small connectors to make it easier for me (and anybody else) to reattach it.

The connectors are color coded.
Black: AFM, AAR
Blue: Fuel Injectors
Brown: TS1
White: Dual Relay, Resistor Pack

Note that the spade connectors are not color coded. So label them when you pull them.

Still Need Help

The Guac has been down since January, but I have little time to troubleshoot. So in troubleshooting time, I`ve spent maybe a week on it.

I`ve isolated things (I think).

Symptoms:
Idles from cold start at least 30 minutes (I figure any longer was pointless)
If revved to 2k rpm and held, will only last 45 seconds or so.
- When it cuts out the tach drops to zero
- There are no warning signs leading up to this
- I can repeat this over and over. So it`s not (or no longer) intermittent

Wiring has been checked and re-checked and re-re-checked. Coil
replaced. I`ve now swapped out 3 different coils and get the same
results. Points and condensor replaced. Distributor replaced. I even
put a compufire on it. Exact same results. Wire wiggling does nothing.

Vacuum leaks have all been sealed. The last one was yesterday, a fuel
injector seal wasn`t seated properly which was probably from previous
troubleshooting. (Yes, I got the rear drum loose. The hammer blows did
it.)

Several dual relays tried. Injectors spray nicely when triggered,
don`t leak when off.

Fuel pressure stays up. When idling and warm the vac is between 14 and
15, which is probably good for Colorado.

The only things I haven`t tried are replacing are the engine (heh),
the resistor pack, and the computer.

I`m leaning toward either computer or ignition due to the way the tach
just flatlines like that. Though I can`t see how the computer would
affect the ignition?

Any thoughts? Things I haven`t tried? Help?

Bucking Under Load

The Guac`s been out of commission for a month while I try to figure out why it`s bucking under load.

Fuel pressure is higher than it should, but it probably doesn`t cause this.

All ignition components tested or replaced.

Valve adjustment complete.

Vacuum gauge steady low.

Photos of fuel pressure test here.

Here`s a video of all the gauges going. Note the jittery timing mark is due to the frames of the camera not lining up with the strobing of the timing light. It`s rock solid.

Bucking Bus Revisited

Ahhh... it wouldn`t be the Guacamole Bus if it didn`t have this @!#$%^ intermittent bucking issue. The problem has been around pretty much since I bought the bus.

Some background is in order I suppose. Shortly after buying the Guac, I did a road trip with the family to California. The day we were supposed to leave for home the bus would act like the ignition was shut off when upshifting or when RPMs went over 3200 or so. The symptom would last for just a moment, then the bus would continue on like nothing happened. It reminds me of a cat that just fell off the bookcase, then sits there licking itself as if it meant to do that.

I replaced the points, condenser, plugs, cap, and rotor. None had any effect. I even bought a new coil from Autozone (read about that piece of crap here. I spent two days extra in CA trying to figure it out. Someone on the Type 2 list suggested replacing the fuel filter. A fuel injected bus is sensitive to fuel interruptions, and this was a logical place to go, even though the symptoms "felt" like they were electrical.

I replaced the filter and the large feeder hose to the pump and VOILA! The bus stopped its bucking! It made it back to CO without nary a whimper.

A month or so later the symptoms returned. I bought another fuel filter and swapped it in and the symptoms went away. This scenario repeated itself at least two dozen times over the next couple months, with me spending a small fortune on filters. I figured the tank was rusting out like the one in my 73 did and I just needed to pull it so I could have it relined. But just to be sure I opened up a filter to see what was causing the blockage.

As you can see, there was no blockage in the filter at all. Aside from a slight darkening in the half of the element that was constantly soaked with fuel, it`s clean and good as new.

Now I was really confused. Why would changing the filter resolve the issue? I looked for more clues.

One thing I found was some scorching in the distributor cap that appeared to be spark jumping from the rotor to the ground strap inside the distributor.

Again, I thought I had fixed it when I put a different distributor in. Not so.

I gave up for a while on fixing it, and just drove through the problem. Using some gas pedal massaging I found that I could keep driving whenever those symptoms appeared.

Until last week.

The bucking and cutting out got so bad that the bus was truly undriveable. I parked it and decided to leave it alone while I went over what I`d replaced and checked, and what I hadn`t.

While I had tested and inspected both the double relay and the AFM, I didn`t swap them out. So I figured this was a great time to try that. I asked Thesykboy to swing by and let me borrow the AFM and double relay from his bus for some testing. When he got here yesterday I quickly swapped in his double relay and started the bus. It idled for a minute than died.

Hmm... His relay must be bad (it was his spare). I tried the known good one from his running bus and got the same result. Then I put mine back in. Same result.

WTF?

I gave up for the day and went inside. Today I went back out to start messing with things. I found if I wiggled the wires going to the thermotime switch I could stall the bus or keep it running indefinitely.

So the TT switch must not be grounding properly, or the wires are loose. There are a pair of crimp connectors on the wires to the TT switch, so those crimps could be bad as well.

I loosened the "T" to the brake booster and tried to remove the TT switch. Screw is frozen tight. But I noticed the TT switch bracket is just flopping around there.

AHA!!! That must be it! I wedged a screwdriver under the TT switch to make sure it was grounding and went for a drive. No symptoms. Yay! Since I can`t get that screw loose, I`m just wedging some steel underneath for now until I can get an impact driver to get it loose.

Now, before I get TOO excited, I need to remember that I`ve been here before. Let`s see if it lasts...

Fuel Injection Mixture - or Why are My Plugs Fouling?

In the article Vacuum Leaks, Smog Test, and Blazer`s Automotive I had a shop find my vacuum leaks and get the Guacamole Bus ready to pass the Colorado emissions test.

They found leaks in my S-boot (I knew there were some there) and my intake manifold gaskets (that was a surprise). They slopped more goop on the S-boot and cranked down the nuts on the mainfolds. They also made some adjustments, but never really specified what those adjustments were. But the bus passed the smog check.

Then I went through and replaced the intake manifold gaskets and the S-boot, as described in Replacing the Intake Manifold Gaskets. Everything is tight as a drum.

Too bad my mixture was WAAAAY off.

My plugs kept fouling, and I was getting like 12mpg. Ugh. Thinking the shop had only messed with timing and the idle mixture screw on the Air Flow Meter, I started going batty trying to figure out why the bus was running so rich.

I pulled the cold start valve out and pressurized the fuel line. No seeping from the valve. It couldn`t be a leaky injector since that would foul only one plug.

I pulled the cover off the Air Flow Meter (AFM) again. The glue on the fine adjustment screw for the wiper is still present, so they must have adjusted the big black wheel. That wheel controls spring tension on the wiper. Essentially, it controls the amount of fuel delivered for a given volume of air. A tighter spring gives less fuel, looser spring gives more.

I initially moved the wheel 5 notches, but still had fouling plugs and poor running. It took me a few days to realize they must have gone more than 5 notches!

I ended up with a total of 12 notches! In the pic below, the white dot is where the arm was pointing when I started. And you can see where the arm (silver bit of wire) is pointing now.

Without a gas analyzer I can`t get it perfect. But I got it close. Here`s how:

• Remove the cover from the AFM


• Mark which notch the arm is in


• Start the bus


• Rev the engine - Watch for smoke from the tailpipe


• Move the black wheel one notch at a time, revving the engine after each change


• When you find a notch that has no smoke and no fuel smell, you`re there!

As I said, you can`t get perfect with this method, but it`ll get you in the ballpark until you can get it to a shop with a sniffer.

While I`m at it, I`ll describe how I set the idle mixture. The screw is at the top of the AFM, often covered with a silver cap. Remove the cap if it`s there. Using either a screwdriver (early busses) or an allen wrench (late busses) adjust the mixture until when a small vacuum line is pulled off the idle rises about 50 rpms. This gives a "rich best idle" which will help with light throttle response and lower head temps in traffic.

Aux Air Regulator Elbow Replacement

"Upgrading" the Aux Air Regulator Elbow

January 24, 2007

Ahh... The first article of the year! Hooray!

Last August while in California, I discovered a vacuum leak in the Auxiliary Air Regulator elbow. This is a right angle elbow that connects the AAR to the S-Boot on the intake. I picked up a new one from VeeDub in Huntington Beach. Coupla bucks and I was back in business.

Fast forward to January. A mere 5 months later.

5 months and the elbow is hardened and split. Nothing like Genuine VW parts, eh?

I refuse to fund the manufacturing of shit parts. Just ain`t gonna happen. So I started looking for other solutions.

First I tried to find another 90 degree rubber elbow, either 13mm or 1/2" inner diameter. I know there`s something out there, but the counter monkeys at the FLAPS around here are useless. Can`t be arsed to look for a part that might actually HELP someone. Then someone on the Type 2 List made a suggestion:

Don, why not get a piece of good rubber hose that will fit over the "outlet"
pipe, then in the other end put a short straight piece of copper tubing,
solder a 90 bend on it, solder another copper short on the other end of the
elbow, and another short good rubber piece as long as you want it, on to
that.

So I thought, what the heck? Time to head to Ace Hardware. Where I found:

A buck and a half got me a copper 90 degree elbow. The OD was a bit more than 1/2", so it`s kinda large but will work. The next size down was way too small.

Comparing the two I found that the copper elbow is a bit smaller than the rubber one. This is good because the location it goes in is VERY tight even for the stock elbow. And I`m going to need a length of rubber hose to go between this elbow and the nipple on the AAR.

But it looked like it would still be too long. Out comes the Dremel (I love that thing!) I cut off a quarter inch or so, leaving just enough of the raised area to act as a lip creating a tight seal. Then I ground the edge mostly smooth to avoid any sharp edges that could cut the hose.

This rig fit nicely. And what`s awesome is I can use any 1/2" hose to replace the rubber, which makes life easier for the future.

Replacing the Intake Manifold Gaskets

Photo Gallery Here

After Blazer`s told me my intakes were leaking, I started gathering the bits I would need to replace them. I already had the gaskets themselves, but I also wanted to replace the intake manifold to plenum sleeves as well as all the injector seals.

Would the old parts have been reusable? Possibly. But I wanted to be certain everything was new.

The sleeves I got from Cip1. I had forgotten to order the injector seals though. So instead of paying $4 for a complete set from Cip1 or Bus Depot, I ended up paying $2.44 per injector. Ugh.

I also had a new reproduction S-Boot from eBay. Yes, I`m happy with my PlastiDip coating job, but if I`ve got the new one anyway, I figured I`d use it. The original one will still be there when I need it.

Everything gathered, I popped the cover on the engine bay.

Typical late bay window fuel injected engine.

First thing I did was remove the air cleaner, AFM, S-Boot and hoses, and the decel valve.

Looks awfully naked! I probably didn`t have to tear it down quite as much as I did, but I wanted to make things as easy on myself as possible.

First, I relieved the fuel pressure on the fuel rail.

I then removed the 3/4 injectors. Remove the 10mm nut and lock washer from the injector retainer plate and loosen the hose clamp at the rail. Do both of the injectors on the same side, then it will be easier to pull them from the intake manifold and then the fuel rail. You can easily remove the electrical plugs now.

You WILL have gas dribbling from the fuel rail when the injectors are removed. Keep rags handy to clean these spills up, and clean the moment any fuel spills. Not only can you start a fire, but the gasoline will eat away at the foam engine compartment tinwork seal.

It is unnecessary to label the plugs on the injectors. All 4 fire at the same time. Still, I like to put everything back the way it was, so I kept track of which plug went to which injector.

Now, the 13mm nuts holding the manifold to the head must come off. I like to loosen them a little at a time until they`re all free just to be certain there is no warpage of the head or manifold. Be sure to catch all the lock washers too.

If you have clamps on the sleeves from the manifolds to the plenum, loosen these. The intake manifold should slide right off the studs and out of the sleeves. If the sleeves won`t let go, and you have spare sleeves, don`t hesitate to attack them with a utility knife/razor blade!

Here is what I found when I pulled mine apart:

The green arrows point to the leak locations. This is the 3/4 head. On the 1/2 side, only the #2 cylinder was leaking. Here`s the 1/2 side:

Yeah, I`d say I was leaking! I`m surprised the bus ran as well as it did!

Now here`s what it`s SUPPOSED to look like:

By the way, can anybody identify the brand of the bad gaskets? I know the new one is Victor Reinz, but I cannot make out the branding on the old ones.

When I got the 3/4 side manifold off, I took a pic of the intakes on the head. I just wanted a peek.

Yes, I cleaned the intakes out and the gasket surface before putting the new gasket on. Sheesh.

The injectors were ugly:

But the ugliness is on the outside, between the fuel rail and the intake manifold. Who cares what THAT looks like. It`s the nozzle inside the manifold that matters, and all four of mine looked good.

I`m glad I replaced the injector seals. The large ones were cracked and ugly, and the small ones (the most important ones) were visibly compressed.

I used new Echlin brand seals from Napa. $2.44 per injector set. One of the large seals came out of the package cracked. But out of the 4 old ones, one was like new, so I used that. Gotta love modern quality control!

I found it to be much easier to install the injectors to the manifold, then install the manifold and attach the injectors to the rails. You can visually check the seal of the injector that way.

So that`s what I did. Injectors to manifold, plug connector pointing up. New gasket on the head studs, install the manifold sleeves on the plenum (air distributor) 1/2" first, then wiggle the manifold into them while guiding it onto the head studs. It sounds harder than it is.

Torque the nuts on the manifold to 14 ft lbs. I built up to that rating in 3 stages: 8ft lbs, 12ft lbs, then finally 14. Again, it may not matter, but better safe than sorry.

Once the manifold is torqued down, and seated into the sleeves, slide the fuel rail nipples into the injector hoses. (Yes, that sounds dirty. Deal with it.) Tighten your clamps.

Repeat for the other side, and reassemble the engine components!

The new S-boot was really nice to work with! I didn`t have to stress over putting new cracks into the old and brittle original S-boot. I have no idea how long this Chinese repop will last, but it will be interesting to see.

One obvious sign of the questionable quality of these reproductions is the mis-aligned mold markings:

So we`ll just have to wait and see what we get out of this new reproduction.

I`ve said before I`d be willing to pay real money, $100 or so, for a Viton rubber quality reproduction. It would last forever, or darn near... Hopefully someone will take up the challenge!

Sealing the Fuel Injection S-Boot

I don`t know about using the term "refurbish". More like "add some life". But "refurbish" is easier to say. So REFURBISH it is!

The S-boot on my 78 fuel injected VW Bus was old, dry, brittle, and had many tiny cracks. It leaked horribly, no matter how much RTV silicone goop or electrical tape was applied.

So I was cruising Home Depot a couple weeks ago, and saw that Plasti-Dip has a spray applicator! I`ve used Plasti-Dip to rubberize tools and handles and such and the stuff lasts a long time.

Why not coat my S-Boot with it? Into the cart it went:

Day before yesterday I pulled the S-Boot (pic above), gave it a quick cleaning, and started spraying the Plasti-Dip. The instructions said as many coats as desired, 30 minutes apart.

Here it is after one coat:

I used the entire can, for a total of 6 coats. Then I hung it to dry overnight.

Yesterday morning I reinstalled it using some black RTV to seal it to the throttle body and air flow meter. I let it set for a couple hours while I finished up the installation of my westy bed.

Then I took it for a test drive. No apparent leaks! I know my intake gaskets are leaking, but that`s another project. It runs smoother than it did previously.

I`ve now been driving it for 2 days and am VERY happy! Let`s see how long it actually lasts!