Points dizzy with EFI

[zed4ps]

Hi, Does anyone know if you can run a standard points dizzy with the l28 and EFI. car is running at the moment but not very well, runs rough and backfires. Sounds like it is running on 4 cyl`s. When i take the leads off 1 & 5 plugs while motor running it makes no difference. Cheers peter

[nizm0zed]

I'll assume its the standard 280zx EFI system?

If yes, then i doubt it'll work with the points dizzy.

 

As for your running rough, sounds like you have narrowed it down to 2 cylinders, now to work out whats wrong in those cylinders.

Try swapping a known good lead onto the cylinder in question. (you can get a new single lead at supercheap for $4)

Also check the leads for spark by grounding them against the block/head/chassis with a screwdriver or something down the guts as a probe,

That'll help to eliminate whether spark is making it to the plug.

If the ignition seems to be ok, next is to check for fuel delivery on those cylinders.

This is easy if the mix isnt igniting because the plugs will be wet with fuel. Pull them out and have a look.

If there is no fuel you can check the injector by using a test light, turn the ignition on and probe one of the wires in the plug while its connected to the injector.

One will show power (12v feed) the other will cause the injector to ground and open up. you'll hear it click.

If they dont click then get them serviced or replace them. Injectors do seize up over time.

Once you have verified you have spark and fuel, you need to check the health of the cylinder.

Do this by doing a dry compression test and then a wet compression test.

You could also do a leak down test if you have access to the equipment.

 

If the cylinder itself is the problem the motor will need to be pulled apart to fix it.

Time to evaluate how much you want to spend, or find a suitable replacement motor.

[zed4ps]

Hi, i have had the motor rebuilt, new injectors ECU checked out, new temp sensor, new fuel regulator and spark getting to all plugs. Not sure if the spark is strong enough due to the points dizzy. Will check other options . cheers peter.

[jamo240]

Hi Zed4ps

 

A points distributor is capable of firing a fuel injected engine. From the spark's point of view, how the fuel gets into the cylinder (via carb or fuel injection) is irrelevant. Given you have two cylinders you suspect are not running right, have you got the plug leads on the right pins to reflect the firing order 1-5-3-6-2-4?

 

As long as your are confident the ECU is getting all the inputs it needs (especially relating to engine speed in this case), then go back to basics. An engine needs compression, fuel and spark to run. Check and make sure each of those things are there (especially on the cylinders you have already identified as not saluting the flag), and you are sure to get it running fine.

 

Cheers

 

Jamo

[Six_Shooter]

If I'm not mistaken the early (non turbo) EFI is triggered from the negative side of the coil, which would mean that the dizzy is not important as to which type it is in that case. Other EFI systems definitely have to use a matching dizzy.

 

Have you verified timing advance, and spark output on those cylinders?

 

Could be as simple as installing a new dizzy can and or rotor.

[Daedalus-Z]

If it's running on 4 cylinders and backfiring, I'd agree it's probably the ignition to those cylinders rather than the injection setup. Plugs, leads, cap, rotor etc. The EFI on the 280 is damn close to being an electronic carby so it *should* work with the points dizzy!

 

Shouldn't affect the missing, but if it's still rough afterwards make sure you're running resistor type plugs. Not sure how sensitive the old EFI setup is to interference, but in theory you should use the 'R' type plugs with injection setups. *shrug* When in doubt a new set of plugs rules out one more thing

[Wayne G]

Are leads 1 and 5 crossed?

[dazzed]

Are leads 1 and 5 crossed?

the 280zx requires a pulse generator signal from the electronic didtributor to send signal to the computer to determine injection cycle there is a  yellow wire at the computer harness connector which goes to negative on the coil this must be connected or no fuel cycle

[zed4ps]

Problem solved, replaced two new spark plugs with another two new ones. Realized you cant run a hose from the outlet on the side of the block to the manifold as this bypasses the air flow regulator and is not considered in the mixture of the air fuel. Thanks to everyone for their input into my problem. Cheers Peter.