914 Fuel Injection, Need an L-Jet Guru!! Options

[Cjllong]

I have a 75 914 with a 2.0 motor. It originally had a 1.8L, but I acquired a 2.0 from a wrecked 73 914. When the 2.0 was rebuilt and installed, the mechanic installed the 1.8L fuel injection system and told me it was superior to the 2.0L fuel injection system. I drove the car for 2 years and never had a problem. All of the sudden, the car wouldn't start. I took it to a local German auto mechanic, (The guy who originally did the conversion left town), and he said he would fix it. Well.... A new fuel pump, plugs, other stuff, and the big one.. a new computer, the darn thing still has the same symptoms. It simply dumps fuel into the valves when starting, causing it to flood almost instantly. He checked the fuel pressure regulator and it seems to be fine. He's telling me that the computer is holding the injectors open too long, causing excessive fuel to flood the motor. $1300.00 later, he says he'll do the rest of the diagnosis for free. I think I payed for his education of the 914 fuel injection system, and I don't think he learned anything. I originaly posted this problem on Pelican Parts and they directed me here and told me to look for Clay Perrine. If your out there, please help me! I'm desperate!

Chris

[ClayPerrine]

Ok.. on to the problem with the L-Jet.


I would look a few things...

1. Check the fuel pressure. Put a gauge on it. Then turn the key on and open the air flow meter flap. Make sure the pressure is at 32psi. I have seen an L-Jet system with a plugged return line create around 100psi. This will definitely flood the motor.

2. Check the cold start injector. Pull it from the plenum, disconnect the wiring, and place it in a jar. Run the fuel pump as described above. It should NOT leak any fuel. If it does, replace it.

3. Check the injectors. Pull them from the intakes and put them in jars. See if any of them leak via the same test as the cold start injector.

4. This one is the most unlikely, because you said it was running good then it quit. And in deference to the Capt'n, the computers are very, very durable. But I have seen an issue where 30+ years of vibration has broken solder joints on the boards in them, causing a poor running problem. This can be exacerbated by the replacement of the 914 L-Jet computer with the wrong year. If you plug a 75 computer into a 74 wiring harness, the contacts for the air flow meter are slightly different, and it will run extremely rich, causing flooding. The reverse is also true, a 74 computer in a 75 open circuits the AFM, causing a flooding condition.

Start with those things, and we can go from there if none of those are the culprit.