[Dutch280Z]

A short introduction:

Hello, my name is Henk from The Netherlands. I purchased a 280z from California 1 year ago. At the time it got here we started the project of getting it road legal.

The state I bought it in:

The pictures above are at the moment I purchased the car from the import guy.

The problem of my z is that it wont run on all cylinders.

Before we started to check what could be the problem we installed new spark plug kit + spar plug wiring + distributor cap & rotor. We replaced the fuel (from 2013) and the did an oil change + oil filter change.

The correct firing order should be 1-5-3-6-2-4 as I have read on this forum. when we follow this it does'nt fire at all. The order that gave the most succes wat 6-2-4-1-5-3. but this meant that the car only ran on 3 cylinders. cylinders 2-4-5 were not running. spark plugs were black, while the others were clean. We did a compression test aswell.

Cylinders:
1 = 110
2 = 110
3 = 110
4 = 115 Note that after this increase of compression the starter motor started spinning faster. (this explains the increase in compression we thought)
5 = 120
6 = 125

When piston 1 was set to TDC the rotor from the distributor cap was at the right position. All 6 Cylinders make spark and all the 6 get fuel. (injectors are working)

Does anyone have any idea what this might be? Getting kinda stuck at this point.

Thanks!

 

[pilgrim]

Your compression is fine. It could be higher but it's very even, so that should not be a problem.

The firing order is not negotiable. Check the factory service manual (Nicoclub.com has it, but don't download the WAVE browser it will offer you). It appears you have checked that the distributor is installed correctly using top dead center on the #1 cylinder as your reference.

Have you changed the distributor cap and rotor, spark plug wires and plugs?? These cars have a very short plug life, about 10,000 miles between plug changes.

 

[kickstand80]

Are you 100% sure you are on TDC of the compression stroke, not the exhaust stroke? Rotor turns counter clockwise. Number 1 plug should be labeled on the distributor cap or rotor is pointing at the radiator. I have seen (I did it) the rotor on backward.
So get the engine to TDC, check the timing mark on the crank damper and check the position of the rotor.

 

[Dutch280Z]

@pilgrim Good to hear the compression is fine. I thought the same about the firing order, but it won't start that way. Yeah the spark plugs + wires + cap etc are brand new, I have just installed them. 0 miles.

@kickstand80. I am 99% sure the TDC is correct. Even checked it with the distributor cap off and it turns counter clockwise as we know. It all lines up.

Went back this morning to put it in the right firing order, still nothing.

 

[kickstand80]

I have seen a 280zx run (very poor) with the incorrect wire order. Are you numbering the cylinders from front to back or back to front? Maybe you have a reverse Polish rotation distributor cap
Is it correct to say that when piston 6 is at the top of the compression stroke you have the 6 wire where the 1 wire should be. 6-2-4-1-5-3 is correct if you have the rotor on 180° off, you are just starting in the middle of the normal 1-5-3-6-2-4. Since this is a new car for you, some one may have installed the oil pump drive shaft 180° off.
Pull the distributor out, rotate engine until piston 1 is at TDC and check the position of the drive tab on the oil pump drive shaft. It should look like this:

Notice that the drive tab is not centered, it should be off set to toward the radiator. Piston 1 at TDC on compression stroke.

 

[pcs1z]

I hope you have the rocker cover off to get the correct piston ([email protected] front) on TDC with both valves closed. Also check the TDC mark on the crankshaft pulley is lined up, and have the distributor cap off to observe the rotor in the No 1 position. The No.1 spark plug lead also has to be in the correct posi. in the cap. The other end of the No.1 lead has to be on the No.1 plug. If all those items are in their correct positions, then the motor will run. If it doesn't start, you have to say "I have got something wrong" and walk it through with another person with some auto knowledge. Sometimes it's hard to find your own fault. Your brain tells you it is correct. That's why the second person is often required. Peter

 

[pilgrim]

Great idea to pull the rocker cover and confirm that the engine is on TDC-compression, not TDC-exhaust.

It does sound to me like this is a possibility.

 

[kickstand80]

Number 1 cylinder at TDC the first two cam lobes should look like bunny ears..............like this

 

[pcs1z]

Yes, That is correct, as both valves are closed, and with the correct use of a match, there should be a bang in the cylinder pushing the piston down. If you have had the timing gear off, then that's another possibility. Peter

 

[madison]

The firing order that works for you is the same as it should be. The difference is that you are starting off halfway through the order. Really seems like you have distributor in wrong gear.

 

[dandyz]

Hello Henk
My opinion is that you have a distributor / timing problem. Start at #1 cylinder TDC and make sure the rotor is pointing at #1.

 

[bergrider]

Original comment deleted.

Also make sure your rotation is correct. Should be Anti-clockwise.

Also separate the wires. That tangled mess you have in photo 1 can lead to an induced voltage in the wrong wire.