WTF!? H22A not starting after short run!

[Cutz]

Right, i'll start at the beginning...

got up today, drove about 5 miles and left the car for about half hour.

came back to it and cranked her over, cranking but not firing at all...then backfire.

tried again....crank and crank and crank then finally a backfire.

so i have a little cry and go off and think about it and come back with a spare main relay thinking that was the culprit...didn't try to restart car (was about 3hrs ago), banged the new main relay on and she started up. "super duper" i exclaimed, drove her home.

on the way home she was running a tad rough on the bottom end and seemed to get progressively worse as i got home...o2 gauge seemed to be going a bit crazy, phoned bucks420 and he rolled straight over so we could investigate.

went out to the car to check everything out, went to turn her over again...load of cranking followed by a half back fire sort of thing...so it can't be the main relay, but it's re-occuring after short periods of time.

here's what we checked:

• spark - appears ok and strong (coil replaced less than 12months ago)
  plugs - appear dry (i.e. no fuel seems present on them)
  main relay - swapped for another
  ecu - swapped for a known good unit
  fuel pump - can be heard priming
  fuel - tank full to the brim with super unleaded
  spark leads - all secure and new
  cap and rotor arm - both new
  timing - was set when tuned and dizzy has not moved
  vacuum lines - all appear good and have all been replaced for new recently

i ran out of time as i'm working tonight so next on the list to check is:

• cracking off the fuel feed line at fuel rail to confirm function & flow of fuel pump and filter
  swapping the injector resistor box for a known good one
  sending 12v to fuel pump to test full operation

my personal opinion was that the main relay had failed, but after replacing with a spare that idea was out the window.

for the fact that fuel doesn't seem to be making it into any cylinders (or enough to be detected) i can only guess it's something common to the fuel system. either:

• fuel not getting through the system from the tank
  injectors not being told to open...only really common component to the injectors is the resistor box

Anyone got any ideas that they think might help here?

typically i've not got a spare ride at the moment and i'm working nights so it's making getting around a bit of a pain

[Vtecmec]

A partially blocked fuel filter gave me hours of headaches once, and gave the same symptoms.

[Thebusofwoe]

Distributor igniter. When that goes down it gives backfires. Try that.

[Cutz]

A partially blocked fuel filter gave me hours of headaches once, and gave the same symptoms.

definately going to be testing that theory tomorrow dude

[Cutz]

Distributor igniter. When that goes down it gives backfires. Try that.

ignitor (i.e. ignition coil) is a new item but i do have a spare which i'll swap out tomorrow and test.

still thinking it's the injector resistor box though...

[EG_H22]

Lol on this mate.
Find out what it is let me know as im having the excact same problem check my thread lol

[Thebusofwoe]

No not the coil. There is another little box inside the dizzy with 4 (I think) connectors. Ignition control module. ICM.

[Thebusofwoe]

Generally when a coil goes down it will cut out the spark completely. Sometimes if a ICM goes down, it can cause random firing order/back fires ect.

[Drax]

the spare main relay may be faulty as well after being left around ive known that to happen - try them in another lude maybe?

[Cutz]

the spare main relay may be faulty as well after being left around ive known that to happen - try them in another lude maybe?

yes you may be right, but i'll open up one of them tomorrow and go over the soldering just to ensure it's all good.