EFI Hassles

[280zx Fever]

Basically my 280zx will not run on all 6..

It will only run on 4 cyl 1-#-#-4-5-6 and not 2-3 at all.

I got the following,

Spark to all cylinders

Good compression - 190 or more in all cylinders

Pulse

And The injectors are squirting fuel more like spraying..

I replaced the injector hoses as they where rotted out..

I also got fuel coming into and out of the rail and the pressure regulator seems to be working great as well as pressure to the rail from the pump..

Any ideas? it must be electrical i think...

It will start up perfectally on 4cyl and idle nicely

Ignition timing is fine aswell.

thanks guys.

[2ManyZs]

While it is runnign, have you checked that the two dead cylinders injectors are firing? Take a long screwdriver, place it on the metal retainer on the injector and put your ear to the end of it(like you would with a stethoscope) and see if you hear the injector clicking... if not, it's probably in the wiring to the injector. The plastic wiring ends that plug onto the injectors are famous for cracking or losing contact. You can buy replacements from MSA and a couple other suppliers luckily. Also, make sure the plug end is securely attached to the injector, the little wire clips sometimes will loosen if the plastic has cracked on the plug.

I'd say it probably the electrical connection to the individual injectors that are the problem if the rest are working fine.....if you recently replaced the hoses, possibly you might have just loosened up a plug that was in bad shape to begin with.

[280zx Fever]

yep i got spark to the dead cylinders ..believe me i know

I had the fuel rail and injectors out still connected and they spray fuel..i got the injectors mixed up when i replaced the hoses but all the 4 cylinders still work so there goes my injector thought and all other signs just point to electrical.

The little wire clips are broken off each clip but i sprayed them with some WD40 blew them out put them back onto the injector and they pulse the injector works fine..

Is there a way to reset the ECU or is just taking the battery lead of sufficent ?

thanks for your help.

[sjcurtis]

280zx Fever,

2ManyZs has offered some very sound advise on the efi connectors and electrics, and your reply suggests you are happy, that it is not the connectors or injectors.

You could still have a number of problems , maybe a blocked fuel filter only allowing enough fuel flow to sustain four cylinders I say a big maybe. mor like below

my first advice is pull the spark plugs from the faulty cylinders and change them for one from the good cylinders. See if the problem moves from one cylinder to the next. Just because it sparks when you are watching does not mean it will work in a compressed enviroment of the cylinder. You may be up for a set of plugs.

Cheers

Steve:classic:

[280zx Fever]

tried that problem still occurs on the bad cylinders.

Dont think it would be the filter because for the simple reason the other injectors would be playing up..not just these 2.....

But it will be all worth it

oh p.s - im not saying 2ManyZ's advice isnt good but thats the sort of conclusion i came to myself.. so...

Im still up for ideas etc

[sjcurtis]

280zx Fever,

Well that makes it more interesting, my next move would be a fuel pressure check against the book (for idle fuel). If that is good, I would suspect an injector blockage/failure. I would now move a failing position injector to a working position and so on for another operational check, and see if the fault moves.

Cheers

Steve:classic:

[St.stephen]

I'm agreeing with SJcurtis with the blockage theory.

Have you flow tested the injectors?

remove the injectors leaving them attached to the rail. Place each injector in a small graduated cylindar (can be obtained from a photo store).

Remove the plugs

disconnect the battery lead to the coil

crank engine for 60 seconds

observe the flow of each injector

if the differance in quantity is greater than 10% either clean or replace the injector.

[Mike]

Try replacing all of the injectors. Before you do so, make sure all of the hoses and lines are clear of debris from the filter to the engine. The best money ever spent!!

[SuDZ]

Originally posted by sjcurtis

maybe a blocked fuel filter

Where is the fuel filter actually located?

SuDZ

[Mike]

Follow the lines... but, if you are standing looking at the engine from the front of the car, the filter will be to your left near the wheel well.

[SuDZ]

Originally posted by Mike

Follow the lines... but, if you are standing looking at the engine from the front of the car, the filter will be to your left near the wheel well.

Thanks. I have to get used to the new location of everything. On my Maxima I know where every little thing is by heart. Now on my 260Z I feel like I am blind always trying to find everything and figure out where things are still. I will get it eventually.

SuDZ

[280zx Fever]

It cant be the injectors..ive sort of ruled that theory out in my head they got mixed up and not put back in the correct order but its still #2 and #3 cylinder not firing..

Could i have ECU problem ?

thanks for the input