Won't start after rebuild

[red107]

This one has got a few of us pulling whats left our our hair out.
1981 fiat spider. Engine was rebuilt, we checked and rechecked the engine timing. Set crank marker to TDC (FWD pointer). Cams line up, just to be sure we rotated the motor a few times by hand to make sure valves were opening and closing at the right time.
The problem seems to be ignition timing. New cap, rotors and wires.
Spark plugs are new but were checked, put a light tester on wires and all four fire, fuel pressure was checked, pulled the plugs and they are all wet with fuel.
Distributor pickup was replaced, gap was set and checked and rechecked.
followed the service manual. set rotor markers correct, it points to #4.
Engine will not fire. Any ideas?

[RRoller123]

TDC set on compression stroke of which cylinder?

[red107]

When Crank shaft marker is TDC 1 and 4 are set. However, when you aligned the camshaft pointers to the crankshaft, #1 in on its compression stroke. The service manual has you set up the ignition timing to fire on #4. It doesn't seem right. We did get the car to run for about 5 seconds by rotating the distributor counterclockwise 90 degrees.

[blazingspider]

When Crank shaft marker is TDC 1 and 4 are set. However, when you aligned the camshaft pointers to the crankshaft, #1 in on its compression stroke. The service manual has you set up the ignition timing to fire on #4. It doesn't seem right

With the crankshaft mark at TDC, and the camshaft marks lined up on the intake and exhaust cams, #4 should be on it's compression stroke not #1. If you pull the camshaft covers, both valves for #4 should be closed when all the marks are lined up. If that's not the case then that's your problem.

The distributor rotor should be pointing to the #4 contact in the cap when everything is set on it's mark.

[red107]

Thanks for the input, you confirmed what I suspected. I do have another question,
Crank is TDC, Cams are properly aligned on their marks, Distributor is Set to fire on #4 why doesn't it fire?
Crank to cam ratio is 2:1. Can the cams be off and marks still line up?

[narfire]

The distributor rotor should be pointing to the #4 contact in the cap when everything is set on it's mark.


I found this out after not being able to get my car to fire after a re-build. The #4 pin is nowhere near the #4 wire outlet.
Also do check the wires inside the dist cap are all in good shape( you said new) and not pinched. ( another issue I had) And.... behind the coil is a module where the wires have come loose and stopped my engine...

[blazingspider]

The camshaft marks will line up in 2 positions but only 1 position will result in having the marks AND the crankshaft mark set at TDC. If you're absolutely positive everything is lined up properly and that you are getting spark and fuel I would try advancing the timing a bit by rotating the distributor a little counterclockwise. When you set all the marks and the distributor properly you're timed at 0 degrees and these cars run and start a lot better at 10 degrees BTDC.

[klweimer]

One of the big advantages in my mind of wasted spark ignitions (like the system Mark sells), is that timing is a piece of cake. I have twice as many chances to get my timing right!
Kirk

[spider2081]

Is there any chance you have the cam gears swapped?? They are side specific for cam timing but will fit on either side.

[red107]

Thanks for all your input. I'm helping a friend with the rebuild, The owner blew the #4 rod threw the block. The rebuild was basically a swap of the block (new rings, bearing). The head was refreshed with new seals and shims for the valve adjustment. Cams were never taken out. I have made the mistake before on my own car with not correctly identifying the #4 contact on the Distributor cap. I will check the cam alignment.