Motor In, But Won't Start

bb · 04-13-2002, 09:22 PM

OK, it's 1:00 a.m. and just went through about 3 hrs of turning the motor that I just rebuilt over with no luck. It is a 76 with CIS.

Is there anything with the CIS that I am missing? The car just turns over and over. It seems to be getting fuel and spark but won't even try to start.

Any suggestions?

Superman · 04-13-2002, 10:11 PM

Forgive me if you know all this. Compression, spark, fuel. That's all it needs. If you've just rebuilt the motor then it's conceivable you have no compression because you put the cams in backwards or something. But chances are you built it fine. A double check would be to see if, at TDC #1, both valves are closed and the piston is at the top. Anyway, once you rule out compression, the it's just fuel and spark.

Pull an spark plug connector and plug it to a good spark plug. Lay the spark plug against a good ground and have someone try to start it. If its a snappy blue spark, then....

At least on an '83, you can run the fuel pump by jumping a couple of terminals on the FP relay socket. This will remove most of the air bubbles in the system and pressurize it. You can put the relay back in, remove the air cleaner, turn on the ignition and push the air flos sensorplate up a tad. On the '83 the FP is triggered by this and the injectors will spray. Pull an injector and place it in a beer bottle and do this, to verify fuel. On earlier CIS systems I have dealt with, it might be necessary to jump the FP for this test, if it is not automatically triggered by the sensor plate moving.

Another thing you can do is go to bed, and look at it tomorrow when the sun's up.

Targa77 · Targa77's Garage

Like the previous post stated, I would check that your dist is pointing to terminal 1 on the dist with the crank at the Z1 mark. If it isn't, rotate the engine another 360 degrees and see if it does now. Then try to crank it. I had removed my dist once and this happened to me. If you are using a Permatune CDS, try this site as well http://www.permatune.com/Technical%20Support/Porsche/911.htm. It has a lot of valuable info even if you aren't using a Permatune.

slakjaw · 04-14-2002, 08:15 AM

are the valves too tight so thay are not closeing all the way?