Tuning problem - breaking down when on boost

[IJ.]

Does it have dual valve springs Tony?

[GPT]

Spark plugs unable to produce spark at high boost?

[redss]

Yes IJ I have tested a couple ,about 180 on the seat but will fit new set while I am at it, trying everything

[IJ.]

Yes IJ I have tested a couple ,about 180 on the seat but will fit new set while I am at it, trying everything

No probs, have you had both covers off for a visual check?

I ask as I broke an outer once and the car did what you describe, was fine for the 100 Km drive home if you kept it out of boost..

[redss]

Hi all Well it turns out the tune was the problem. After much expense and hair pulling took it back to original tuner and found it was dumping too much fuel too soon. E85 likes to run a little on the lean side. Plug gap needs to be very tight also 18 thou on my setup.

[ls2 cruiser]

bloody tuners hey. What type of plug are you running and the number?

[redss]

NGK b8efs they seem to work ok. Yes right about the tuner, cost me a small fortune.

[Tre-Cool]

i run ngk br7efs in all my boosted motors, most of then have around 30 thou even with close to 20psi and not had spark blow out, even on filthy rich mixtures.

you can pretty much put the 7's straight in outta the box.