87 D21 Z24 4cyl Ignition Problem

[Milkisgood]

Just replaced the cylinder head on my truck, was blown between 3rd and 4th cylinder. Engine starts, runs for about 3 seconds, then seems to just cut out for 1 or 2 seconds, then revs up again. We have put a timing light on it and the timing light flickers when the engine is running, then just quits for 1 or 2 seconds, and starts firing again.

Does anybody know what the problem is? Do I need a new distributor? Or have I installed something wrong?

[Milkisgood]

Oh yeah I should say it has all new spark plugs, distributor cap, and plug wires.

[zanegrey]

1st check the optiplate in the dizzy ,see if it is dirty or blocked.
it is underneath the plate on the inside bottom of the dizzy.
underneath the cap and rotor. u will have to remove the rotor button and unscrew the plate..

[Milkisgood]

Ok. Checked it, no problems in there. Clean as a whistle actually. I was asking a friend what he thought it was, he thinks I have my vacuum lines connected wrong... been searching for a vacuum diagram online and cant find one. The haynes manual doesnt have one either. Anybody know where I can find one?

[zanegrey]

it should have a sticker on the underneath of the hood.

[Milkisgood]

There is a sticker under the hood, but it doesn't have a vacuum line information. I wonder if I just block the vacuum advance and see what happens. What do you think?

[zanegrey]

i think that an 87 nissan truck with a z24 engine does not have a vacuum advance for the dizzy.

[Milkisgood]

Shoot. Ok, well then I have no idea the problem is. The only thing I am not sure I put together exactly right is the vacuum lines, so I geuss I will try and figure out how its supposed to go together. Thanks