I have an intense vibration, an odd sound during WOT, at high RPMS and full boost. Any help diagnosing this appreciated. It does not do this at high RPMs parked and rev-ed without boost. https://www.youtube.com/embed/843RQCEVz3k
I have an intense vibration, an odd sound during WOT, at high RPMS and full boost. Any help diagnosing this appreciated. It does not do this at high RPMs parked and rev-ed without boost. https://www.youtube.com/embed/843RQCEVz3k
Could this be a leaky exhaust manifold?
In reply to Mike: ex manifold was re-surfaced. New 2.5in Ex system.
Almost feels like it is skipping at WOT. IS this valve flutter?
It does sound like spark blowout, but its happening from lower revs than I have experienced it.
What gap are you running?
Misfire under load, I would be concerned about lean. Fuel system?
In reply to 1988RedT2:
Rich. Stock plug gap. aprox 10psi boost
couple of thoughts - electrical - plugs - not gapped for the car, plug wire or coil going south, loose wire. Fuel, not enough pressure/flow at WOT, mix going out at WOT - vacuum or other air leak
Seems to sound exactly like this one I found on youtube
The easiest way to check if its the spark getting blown is to reduce the gap.
I have no idea what car, turbo size or hp you are running with 10psig; but dont be scared to run a smaller gap than factory. I've had to run as little as .02" on a supercharged S2000.
Mine would only happen on very cold nights here in south Florida.
Did you gap with feeler gauges or the disk "gapper"? Cause I've measured my 99 cent autozone gapper and it was off everywhere by .010 which would make a big difference. Have you checked all your grounds also? Not sure of the car but also is the rest of your ignition system up to snuff? cap, rotor, wires ect.
Next and this part is more important. How rich exactly are you? I had a turbo car act the same when it was way too rich and thought it was blowout for the longest time. It wouldn't hurt to post up a description of your car and modifications.
I gapped my plugs .010 more and ordered new wires. Once they come in I'll report back.
What do you mean .010 more? You gapped them with a smaller gap?
.010 is quite a bit to lower in one shot, I would try closing it by .005 first. Too little gap and then you might start fouling plugs.
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