TheSamba.com :: View topic - Best Year for Aircooled Vanagon Fuel Injection

Mon Mar 24, 2008 10:43 am

I have a '79 California bus, the only year with an 02 sensor...
This, being the first year for the loop, and because it has a tendency to run hot...
Thinking that VW worked on this, and got it better later...

Did the 80 81 82 L-Jet aircoolers have a different (better, richer) fuel map?
Is there one (maybe the last one?) that is better than the others?

Mon Mar 24, 2008 2:49 pm

They're all the same from 80 to mid 83. They use all of the same components. The only difference would be California models vs the rest of us.

I was just looking at my fuel injection book and it says they started using the A.F.C. fuel injection in 74.

Mon Mar 24, 2008 2:59 pm

the brain and afm are not the same 80-83(speakin about federal models)....at some point along the way they got rid of temp sensor 1 and maybe screwed around with some other things, its a bit fuzzy right now.....if your lookin at busdepot and the such and see how they have an afm for 80-83, its really only for the 83 iirc but will function in the earlier models.....if your thinking of changin fi theres always cis parts in all the yards

Mon Mar 24, 2008 4:19 pm

Did the Fereral 80-83 models have O2 sensors?
or just CA?

They still have the Wide Open Throttle switch?

How about the resistor pack integrated into the computer?

I am now married to L-Jet because of The Governator.
Want to find the best year going forward from where I am, instead of backwards.

The 77-78 Federal model conversion would require new harness and resistor pack and computer, but it's supposed to feed the motor a healthier mixture.

Maybe VW dialed things in better as they went?
Many times they seem to.
Sure, many times they did dumb things to save money or try to get them to run cleaner, but not always..
The WOT switch came _back_ after being gone for 77-78 right?

I really like watching the WOT switch on my gauge.
You can hear the tone change, as the motor suddenly gets the fuel it really wants.
off of the switch, just a little, it seems lean.

I want to get a couple of different computers from Vanagons and see if/how the fuel delivery changes on my wideband.

The FI system is otherwise the same as my 79 CA, right?
Could safely assume that if I'm noodling with the AFM spring anyways, the AFM I have would work?

Thanks again for the help.
I don't really have any experience changing these things, only just trying to get what i have right.

Mon Mar 24, 2008 4:39 pm

Spend some time with the exhaust gas analyzer and no noodling with the AFM unless you have one and your Bentley manual open.

Botht eh advance and retard sides of the distributor should be able to hold a vacuum if you have a hand vacuum pump. The EEC valve at the air cleaner should also.

Do you have a cylinder head temp gauge on this thing? You should.

It pays to have injectors that have been cleaned and calibrated also.

Make sure you are plumbed this way and that you have no vacuum leaks....

Mon Mar 24, 2008 6:10 pm

I have a CA '80 model, and have read a lot about them vs the federal models. First, if you want to go federal - get a donor van and have all of the parts on hand. Primarily, the wiring harness is different, as well as other parts like the ECU. So get ready to replace a lot. The AFM is different, distributor (maybe you can keep the electronic ignition), coil, idle stabilzer, starter wiring, double relay, etc. Trace out the diagrams in Bently for hours. I've come to terms with it, but thru a lot of experimentation. Good Luck!

BTW: If you do the switch be <sure> to get rid of the CA exhaust - it's a real cruel joke!

Mon Mar 24, 2008 6:31 pm

Mon Mar 24, 2008 7:02 pm

Thanks for the spelling lesson, that 'e' should add a lot to his comprehension.

Actually, the best exhaust swap is to go with the 72-74 muffler conversion. There is only a small difference between the CA and federal as far as performance goes, but a big difference if you just trash the whole cross-over pipe concept. But my condolences if you need to obey your local laws.

Tue Mar 25, 2008 3:55 am

terryg wrote: Actually, the best exhaust swap is to go with the 72-74 muffler conversion. There is only a small difference between the CA and federal as far as performance goes, but a big difference if you just trash the whole cross-over pipe concept. But my condolences if you need to obey your local laws.

You will never get it top pass emisssion testing in CA however.

I would send a PM off to Karl over in the baywindow forum myself.

Tue Mar 25, 2008 12:12 pm

Thanks for the help.
This motor is basically a Camper Special.
RAT 9550 cam and 7424 heads 72-74 exhaust and 'Thunderbird'
New harness, injectors, etc...
Was wanting to make sure that, while it's going to take a lot of time to tune it, I was using a good year to start with...

Tue Mar 25, 2008 12:30 pm

How have you mounted the O2 sensor and the cat converter?

Tue Mar 25, 2008 3:28 pm

My van started out as a 76 Federal.
Regular gas - No cat.
Helpful at emissions time.

The O2 sender used to be added to the "U" bend on the 76 exhaust.
The one right before the muffler, downstream from the heater boxes.
I had two of them; one for the computer and one for a CB narrowband.

The bus ran so hot it completely MELTED (!) the heads clear off of both senders.

This time, with the "Thunderbird", I'm taking two of the flanges, welded to a length of pipe with bungs for the O2 senders.
Like the one CB sells, only bigger....