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HybridZ

have fuel and spark, still not firing


spiff

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Spiffy, thanks for the reply.

 

Really quick, you are right about the optical dizzy being a different shaft connecting to the oil pump.  That was the original reason for me swapping out the oil pump.

 

So, I did a turbo swap, and the car would ignite, but the timing was consistently 55 degrees advanced when I checked the timing.  I figured that it might be a good time to upgrade to the optical dizzy from the 82/83 turbo.  So I put the car on stands and swapped out the oil pump.  When installing the pump, I used a similar method to what you outlined.  I removed the valve rocker cover, and positioned it so the camshaft showed at TDC on cylinder 1.  Just to make sure, I removed spark plug #1 and put a feeler gauge to check the #1 piston position in the cylinder; the piston was indeed at TDC.  I then installed the oil pump as per the FSM.  While the shaft is a little different on the 82/83 turbo dizzy, it still has the half-moon, and it was the same position as the picture.  I even put a rod through the #1 spark plug on the dizzy cap, and then through the rotor to make sure it was all lined up.  Tried to fire it up, and had a similar experience, the starter would engage, but it couldn't get it to fire up.  The engine would just backfire.

 

After checking, and checking, and rechecking everything, finally I just decided to installed the spindle 180 degrees off.  Finally, it would fire up and stay running.  Problem is that timing still shows 55-60 degrees advanced.  I tried advancing the phasing by installing the pump slightly more advanced, but it wouldn't run more than a few minutes when the timing showed 40 degrees advanced.

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  • 2 months later...

Sorry to bring the subject back up, but I'm also having some trouble with my l28et 240z swap. The motor currently runs but very rough, there is a constant miss/dead cylinder. I have been searching for a solution for the pass month and I can't seem to pinpoint the source. Hopefully a fellow z member can point me in the right direction. The last time the motor ran was over a year ago, it ran fine with no misfire or hesitations. Besides having a 82 ecu running off 300zx coil and ignitor, the motor was bone stock. Since then, I have pulled the head off and replaced it with a pick and pull special, swap 82 oil pump and distributor and some aftermarket parts.

 

Current Setup:

1981 280zx motor

1981 wiring harness/ injector resistors/  MAF & sensors 

1982 oil pump and distributor

1982 Turbo ECU

300zx Ignitor and Coil

Palnet fuel rail

Walbro fuel pump

Stock injectors and regulator

75 280zx fuel tank

N42 Intake w/ 240sx TB & TB sensor

Intercooler (12x24) with 2.5 piping

Greddy RS BOV

 

Tests:

Compression: all cylinders between 130- 137psi

Cylinder Leak Down: @ 35psi, all 6 cylinders lost about 5 Psi

Fuel Gauge: 35psi

Vacuum: Fluctuates rapidly between 14-17 @ idle

 

When I have my timing light on number 1 wire, I get a steady pulsating light then a slight glitch/miss

Can someone confirm that the oil pump shaft and distributor is correct?

Timing is at 20degreee with distributor cranked all the way counter clockwise.

Spark plugs, cap, rotor, and wires are brand new.

65bw9d.jpg

 

 

Distributor cranked all the way counter clockwise, does not line up with number 1 wire.

a07vom.jpg

 

Can someone also confirm that I have the 300zx coil and ignitor connected properly?

At the T connector the blue wire goes to the top of the T

 

1zyygkx.jpg

Edited by voong413
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Thanks for the response, I just had the tank cleaned and sealed so gasoline in the system is fresh. The missfire/dead cylinder seem to repeat itself like a pattern. Which is why I suspect it's an mechanical part that rotates or a sensor giving the wrong data to the pcm to fire the spark.

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That's exactly what I'm trying to figure out. I pulled the motor and swapped over all the parts at once, including the wiring harness, so I can't really narrow it down to one specific part.  I replaced the head, installed new valve seals, upgraded to n42 intake manifold, 240sx throttle body, TB sensor, intercooler, bov, Pallnet fuel rail, and 82 distributor with crank sensor. When I fired up the the new setup, the first 3 cylinders were not firing. I rechecked TDC and realized the oil pump shaft was off. I readjusted the shaft and all 6 cylinders began to fire, but I would get these constant misfire and cylinders not firing. After I readjusted the oil pump shaft I'm also having a hard time adjusting timing. The distributor had to be turned all the way counter clockwise to get timing to 20 degree. 

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