TTAC’s very own David Holzman writes:
Sajeev,
My friend Polly’s ’83 air cooled, fuel injected, VW Vanagon dies at stoplights, and she has to let it cool down before it will start again. It also runs a bit rough, and it’s normally hard to start.
The engine was rebuilt 5 years ago (in Sturgis, South Dakota, where she’d gone from her home in Bethesda Maryland, for a sheepdog trial, by a VW mechanic whom she rousted out of retirement), and she thinks she’s put less than 20k on the clock since. In efforts to solve the problem, the air flow meter, the wiring, and the spark plugs have been replaced.
Any ideas? Thanks!
Sajeev replies:
In these cases, I go back to a couple of fundamentals of the internal combustion engine: fuel and spark. One of them is misbehaving. I am far from a Vanagon-guru, so let’s discuss the common test points for any EFI system.
Fuel is pretty simple to test: a fuel pressure gauge is mandatory for EFI controlled cars. Depending on the manufacturer, a fuel injected vehicle needs anywhere from 10-40psi of pressure to keep the motor happy in any temperature, any driving condition. If the Vanagon’s fuel system is out of spec, test the pressure regulator (normally that means blocking off the return line, but I can’t comment specifically on this application) and the fuel pump.
But I suspect it’s the other part of the equation: ignition. From start up to full throttle, heat is an ignition system’s deadly enemy. I‘d check the Vanagon’s baseline ignition timing (and whatever timing advance mechanisms exist on the distributor) the resistance of the coil and maybe the ignition module. Shouldn’t be too difficult for a VW whiz, and hopefully the cheapest part is the only problem.
(Send your queries to mehta@ttac.com)
They used to develop intake leaks, and they are very much affected by temperature.
Is the hard to start when cold or after one of these engine-outs?
Could it be heat-soak into the fuel lines/supply somehow?
I had a 7M-GTE based Toyota Supra that did exactly that after I forgot to replace a piece of heat-shielding.
This is a long shot but my brother owned a 1970s VW camper that had an engine rebuild and the distributor was reinstalled incorrectly and caused the engine to run roughly.
Just as a side note, everybody, and I mean EVERYBODY, that I ever knew who drove a VW bus out west in high temperatures burned out the engine. The explanation that I heard was that this was due to insufficient cooling to cylinder number 3.
C’mon tell the truth. She went to Sturgis for Bike Week and just won’t admit it.
I’m thinking fuel too. Pressure is definitely the place to start. Don’t know anything about the system but could a leaking injector cause it to die rich at idle then flood preventing easy restart? She needs to find an old veteran VW mechanic.
I vote for fuel pump or fuel filter. The lowered pressure is allowing vapor pressure to build up when hot and shutting it off. The pump overcomes the pressure and keeps fuel liquid
Sure sounds like an intake leak.
I’d say it’s the badge on the front of the vehicle.
The only recommendation I have is to get rid of it right away!
I’ll give her $500 for it right now.
I have no experience with gas VWs, but there is a Vanagon mailing list that might help at http://gerry.vanagon.com. Don’t know if it’s still active, but there are archives. Also, the guy I use for non-engine work on my TDI does a lot of work on aircooled VWs and seems to know what he’s doing. He’s in South Portland, Maine though.
If all else fails, have her ditch it and buy a Routan. ;)
haha XD
At least it still starts. PAD My old Audi 5000 still starts, thanks to a Pad battery enhancer charger on the front.
Needs some engine swap love. Rid the transporter of what ails it and insert a newer more potent VW/Audi or Subaru engine.
Start by testing the Temperature Sensor II with an ohmmeter. Replacing the Bosch L-Jetronic components willy nilly without bench testing them gets expensive.
http://www.ratwell.com/technical/TempSensorII.html
If this person intends to keep this puppy on the road, then he or she will need both the Bentley Factory Manual which is available online and the Bosch Fuel Injection and Engine Management manual, which looks like this:
http://www.germansupply.com/home/customer/home.php
I love the VW bus. When I was a climbing bum we drove everywhere in these things. It’s the only car (not mine) that has stranded me in the middle of nowhere. More than once.
I agree with Juniper…A VW bus that “just passed through” Sturgis? While the bikers were there? I suspect some kind of STD. (for the bus, of course)
I had two two of these air cooled Vanagons, both went to well over 200k w/no re-build. The L Jetronic FI on these is pretty simple and bulletproof and there are only a few things that can go wrong. The temp sensor on the head might be faulty. The Oxygen Sensor and would be another thing I would check, as it can get ruined by a number of things during the re-build. It’s most likely something stupid like a vac leak or loose wire tho IMHO. Check the ribbed heavy rubber pipe downstream from the filter, take a good look at the underneath and flex the pipe to see if any holes open up. In any case, use your nose and try to figure out weather it is running lean or rich. the PCV valve could be shot or one of the other vacuum connected parts. The Coil and Condensor can be temp sensitive as they fail in that expansion and contraction can open & close cracks and whatnot. I had a condensor that did this and it took for ever to figure it out. Check all the electrical connections to the sensors.
http://www.gowesty.com
and
http://www.thesamba.com
It’s where I get everything I need to keep my Vanagon Westfalia on the road. This includes parts and technical direction.
She has another Vanagon with the subaru engine, and that’s another story
“She has another Vanagon with the subaru engine, and that’s another story.”
A post 83 1/2 Vanagon with a Subby engine done right is an awesome machine. It’ll walk away from a standard wasserbox on any steep incline. Torque, HP and MPG are a much better with the Subaru engine
On this air cooled Vanagon, change the fuel filter, check those vacuum lines and electrical connectors for the L-Jetronic FI.
Needs some engine swap love. Rid the transporter of what ails it and insert a newer more potent VW/Audi or Subaru engine.
She has another Vanagon with the subaru engine, and that’s another story
A post 83 1/2 Vanagon with a Subby engine done right is an awesome machine.
If you really do need a new motor in this thing you don’t want another uncommon motor and underengineered swap, that is why a Subaru swapped Vanagon is “another story” ha. You want a reliable, common easy to fix motor a la http://www.bostig.com. full diclosure: A friend of mine owns the place.
If you just want to get it running right as-is Brady at Bostig, or really any of the message boards, might be able to help out, or at least point you in the right direction of someone in your area.
Just for grins, swap in a known good coil. It is more likely backed off head studs or an intake leak, but it is easy to eliminate.
Junk it.