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Thu May 15, 2003 9:53 pm

I just purchased a 1979 Convertible and I am about to rebuild the motor. The car of course is fuel injected and came with many of the parts to rebuild the motor including rebuilt heads set up for fuel injection. I have never owned a fuel injected air-cooled VW and I was wondering should I keep the FI system or drop it for a regular carb setup? If you recommend carburetion, what type of carb(s) would you recommend. Thanks

Fri May 16, 2003 5:28 am

If you have all the fuel injection parts and you want to keep it stock go ahead and use them, if you don't have all the parts some of them can be expensive and it may be cheeper to go with a carb set up, as far as the heads the only difference is the threaded spot to put the cylinder head temp senser, If the block is from a fuelinjected car there will not be a place to put the mechanical type fuel pump and the fuel injected pump puts out way to much pressure, you would need an electric pump that runs about 2.5 pounds of pressure.
My 1979 Super Beetle is still fuel injected and I have had no problems and would not consider changing to a carb, I have worked on some of my friends fuel injected bugs and the injection system is very simple and easy to work with just let it intimadate you into thinking its to complacted.

Fri May 16, 2003 8:24 am

Thanks for your response. It seems that most people have abandoned the FI systems in favor of carbs. However, I would really like to keep it stock since the car is mostly original. Does anyone know of any modifications that can be done to a FI engine such as cam, etc that will increase performance. Or will any changes like this upset the FI system. I am not looking for any major changes, but I thought I would try to squeeze out a few extra HP since I am rebuilding it anyway. Any suggestions would be appreciated. Thanks!

Fri May 16, 2003 9:22 am

If your keeping it FI you cannot do much of anything for performance. I could be wrong though there may be some things I have not heard about.
but the system on your car was only used form 75 -79 so not that many made comparatively. and that means no market for profit, not much $ spent on R & D etc.

I think changing the cam would affect the way the FI was designed to run.
unless someone has worked on a special grind recently I don't know about.
and the FI exhaust system is nightmare that you can't just " throw a header on it"

these older FI's are not as "smart" as the new FI on modern cars that we are all getting so accustomed to so as far as I know, tuning options are limited.

Fri May 16, 2003 2:10 pm

Keifernet is right. As far as the L-jetronic fuel-injection goes, there isn't anything you can do to the engine performance wise. The L in L-jetronic stands for "luft" which in german means air. AFC or air flow control. The amount of air entering the engine is controlled by a flap inside a small metal box that is attached to the aircleaner. The flap can only go so far, and the ECU or computer will only be able to inject so much fuel, according to that flap, or Air Meter Box. This system was specifically designed for fuel-economy/efficiency, so there really isn't any room for improvement as far as performance goes. The good news, however, is that Fuel-injected bugs have 2 more horsepower than their stock carbed brothers. And with a fresh 1600 motor, you should be quite pleased with the power/acceleration ability of the FI bug. I have a website http://75_super.tripod.com about my fuel-injected bug. I have a small tech section, which I need to add to when I have time. There are also some links to L-jetronic specific websites. There is a way to contact me through my website. Please feel free to and I will try to answer any tech questions you have.
good luck!
75 super

Sat May 17, 2003 2:34 pm

I dont remember if it is intake or exh. valves, but one is smaller than stock carb heads. Also the sensor in the head as brettaltman said. As far as cost goes, Carb's are cheaper and there are more motor upgrades.

Sat May 17, 2003 2:50 pm

on the type 1 FI heads all the valves are smaller than a carb head.

Wed May 21, 2003 6:50 am

Bosch makes a very good fuel injection manual, it covers all Bosch injection systems, but breaks them down by type and car, it will tell just about anything you need to know. And buy the way I ment to say DON'T let it intimidate you into thinking its complicated.