5th gear + wot = knock :(

[cyrusdrum]

I have a few problems with my car the most serious is knock when i get on it in 5th gear on the highway. Right about 3000rpm or so when i am at full boost it starts to knock real bad. I can't hear it but pocket logger says so, it also seems to stutter sometimes durring acceleration. I think it is a fuel problem maybe the fuel pump is going bad I also have an exhaust leak where the o2 connects to the down pipe, this wouldn't cause knock would it?? I anyone has any ideas let me know. Thank

Tim

 

[Prez]

I have a few problems with my car the most serious is knock when i get on it in 5th gear on the highway. Right about 3000rpm or so when i am at full boost it starts to knock real bad. I can't hear it but pocket logger says so, it also seems to stutter sometimes durring acceleration. I think it is a fuel problem maybe the fuel pump is going bad I also have an exhaust leak where the o2 connects to the down pipe, this wouldn't cause knock would it?? I anyone has any ideas let me know. Thank

Tim

Going WOT in 5th gear isn't exactlly the best thing to do. That is the hardest on your engine due to the load. Going to WOT in 5th gear if your not tuneed properlly for it can cause some very nasty things to happen inside your engine.

Get some more fuel in there or don't due WOT runs in 5th.

 

[cyrusdrum]

I know WOT in 5th puts a lot of load on the engine, but everything is still stock except the exhaust. Seems like there would be enough fuel unless the pump was going bad. The injector duty cycle was only at like 40%. Is there a way I can test the pump?

Tim

 

[psychlow]

You don't have a boost gauge? If you do, are you getting boost creep?

Has your MAF been hacked at all?

Can you post a log?

 

[Omega]

Have you done your general maintenance... plugs, wires, things of that nature?

 

[cyrusdrum]

I do have a boost gauge and I get boost creep at high rpm but i was getting knock pretty low. I have not hacked the maf but it does not have the outer cover over the filter. I don't have a log, I just had an alarm on my logger to go off when i was getting 15+ knock and it went up to like 43. I have replaced my plugs but not my wires, it may also be a coil problem. it was not grounded well for a while but i thought i fixed it. Would bad spark cause knock?