Hi Corvette guys

I'm just jumping over from the Pistonheads Forum as i was told that one of you wonderful people may be able to assist....

What i'm looking for is a local (Colchester, Essex, UK) LS2 expert who may be able to diagnose and fix the following issue. Unfortunately my automotive expertise amounts to diddly squat. Here goes...

I have an LS2 engine in a kit-car application which is suffering some fueling issues.
When applying a reasonable amount of throttle, i.e. under load, i get a very large kick-back before power is restored. I'm keeping the throttle in a steady position whilst all hell is let loose and the power comes back in. This car weighs 650KG so when the power does come back it's a rather unpleasant experience involving white knuckles and ditch-dodging.

This is what has been ruled-out so far:
a) ECU Map - Standard GM ECU and the map has been checked and is ok.
b) Fuel Pump - A more than adequate specced in-tank pump.
c) Fuel Pressure - Remains constant, even mid-'moment' at 58psi
d) Injectors - Stock LS2

ECU Diagnostics is suggesting that at the point the problem occurs there is no fuel. However if the spark is dying then fuel wont be burnt it will show lean in the exhaust as the sensors measure oxygen not fuel.

I'm sure it's a bank and not a single cylinder. This is not a mild misfire.

Suspect:
Injector/Coil Loom ?
Wiring ?

So, if anyone knows someone local to me that maybe able to diagnose and fix the problem, i would be most grateful !

Thanks in advance
Linkin

 

Do you have HP Tuners or EFI Live?

 

You're misguided with the diagnosis of loosing spark /going lean.
If engine loses ignition, there will be a overly rich condition. I would say with a hand held scan device that displays real time data.
1. Check your Throttle position sensor make sure it reads smoothly as throttle is applied.
2. Check you crank position sensor
3. Check your cam position sensor
Is your car setup to display a Check Eng lite (CEL) if the ECU records a fault?
One injector going bad will not cause drastic behavior as you describe.
Seeing as this is a LS swap into something else verify your grounds are good and constant. Make sure you ground from the battery to the frame and from the engine to the frame. And a ground from the ECU to the engine. There should be more than one ground.
Is your fuel pressure measured post injectors or pre injectors?

 

Actually... the oxygen sensors read OXYGEN, so unburned oxygen will show up as lean no matter the cause. Rich misfires will even show up as lean from the unburned oxygen..

 

Here's a good read on O2 sensorshttps://en.wikipedia.org/wiki/Oxygen_sensor

 

In answer, yes, i have had the ECU checked with EFI live and all looked ok.
Thanks for the replies guys.
I'll report back when the problem gets fixed - thanks for the pointers