Hi Tony,
Sounds like a fuelling problem.... when it won't start after cranking, and you pull a spark plug, it is wet with fuel ?

Try starting it with foot to the floor.

 

Tony,
I am with Chris on this. My old Z car used to do this from time to time. It was a flood condition - would crank, almost start but refuse. So, I would pull all the plugs and get rid of all the fuel in each of the cylinders. Don't ask how. I did it very dangerously. Cleaned the plugs, put them in and it would start right up. Worth a try.

 

When they flood they won't start no matter what you do, occasional splutter but thats it. Remove the plugs (+4's flood much easier than the normal platinum's), pull the fuel pump relay and wires to the ignition modules on the front.

Turn the engine over without the plugs to help purge the system.

Easy to try, and of course it could be something completely different but seeing as the injectors are what you messed with

Chris

 

Pulled all the plugs a few moments ago. Passenger side wet..driver side dry.
Explains why it is "catching" and wanting to start. So im defintiely onto something now.

Looking ahead here...What would cause a bank( driver or passenger side) of injectors not to fire or deliver fuel?



Time to try somethign else..off to the wiring schematics JOY.

BRB....

 

Way to go Chris. Tony ... Tony ... LH baby.

 

You checked spart on both banks ?

J Speake can confirm but all the injectors from the LH are fired at once, the wiring harness splits the connection into two banks, likely not far from the coolant tank.

The heat shrink gets pretty crispy with age, if you moved the cable around when you replaced the injectors maybe you craked it and put extra stress on the inner wires ?

Glad you are getting somewhere ....

Chris

 

Well thisis where im at now.

Both coils produce a spark.....................................tested individually
All 8 points from the distributor produce a spark......tested individually.

All 8 injectors plugs hooked up to my little "bulb tester" one by one and tested and each one flashes as the motor cranks.

Pulled all plugs. Driver side appear dry...Passeneger side appears wet.

This morning i grab a 1.5 gallon gas can and went to get gas and tossed that in the tank. Just in case some bizzare fuel gauge problem!! As you can see im getting desperate in my ways With fuel pressure i was certain of fuel in the tank but ...ya never know right!! Never trust a gauge!

Loosened the fuel fitting from the front damper that leads to each fuel rail. Fuel is present from both fittings when loose. (at 50psi..it wasnt hard to check )



Question.
the "flashing bulb" i have used on the injector plugs gives the same indiaction on both banks of injectors....flashes when cranks.
To me this indicates that the voltage is present and cycling..and should be a resonable test whether the injectors are firing..

Could there still be the chance that one bank isnt working?

This is good isnt it!!

 

That was checked last night. I put it in another S4 and it started with ZERO hesitation. Thanks again Thanit!
I have SPARK...so its not the EZK.

... its Noon, time for a ShinerBock

Thanks for all you input so far.

 

I'd be tempted to go buy some new plugs, and try again ... just my 0.02c.

The fact that the bulb flash's on all 8 injector plugs tell you none of them are shorted or have a bad contact to ground, unless when you plug them back on the injector it causes the stress to make/break but I doubt it.

Chris

 

Here is a queer .03c opinion for you. Are you sure the injectors (all) are actually squirting? Your test says they should be but are they? I don't know **** and have the attention span of a bat but hey you never know.

 

on the bank that is wet, what if you unplug all of those injectors - then do your original fuel injector test? (crank car and see if fuel pressure goes down because the injectors should be spewing gas)

 

ooooohhh...good one! Im all cleaned up but i will run down and do that one RIGHT now! Never thought of that!

 

BINGO!

Mike i owe you a beer for that one!

Fuel pressure was up..I pulled the fuel pump relay then went to the injectors and pulled all the passenger side connectors ("wet side plugs") so the driverside would be the only one able to "fire". I cranked and the Fuel pressure DID NOT DROP!!

I then left the drivers side unplugged and plugged in the pass side bank. Now the passenger side would be the only ones to fire. I cranked and the fuel pressure drop RIGHT AWAY!

OK...NOW WHY?
Why do i have only one bank(passenger) of injectors firing?


Im thinking a ground? As the bulb was a good check for individual injectors but when they all fire at the same time the ground isnt good enough?

Ill head to the diagrams in a few..but where are the injectors "grounded"..are there 2 seperate circuits even though they all fire at the same time?

I guess the flashng bulb test is worthless to some extent!
Good call Mike, amazing how the obvious ideas arent that obvious to others! !

 

Sound familiar...?

Good luck with your hunt for the gremlin...!

 

Where do you measure fuel pressure? Could the fuel pressure regulator on the end of that fuel rail be bad/misadjusted?