Knock

Cory9584 · 11-20-2005, 01:19 PM

What causes a slight knock while accelerating in the lower rpms and usually in second gear?

944 Ecology · 11-20-2005, 02:16 PM

Bad knock sensor???

Cory9584 · 11-20-2005, 02:30 PM

the knock sensor only senses knock tho, it couldent cause it

944 Ecology · 11-20-2005, 02:49 PM

Well, yes, I understand, but, if the knock sensor was bad, it wouldn't detect the knock and then the klr wouldn't be able to retard the ignition to stop the knock from happening.

So, if you really want to know what's causing the knock, it's that the ignition is happening too early for the kind of gas that you are running. Try some 104 octane racing fuel and see if the knock goes away.

gb

Cory9584 · 11-20-2005, 08:33 PM

right now im using 93 and im using an mbc set for stock boost. With the mbc the turbo comes up alot quicker so im thinking maybe it has too much power at too low speed? If that makes any sense

AaronM · 11-21-2005, 02:20 AM

Quote:

Originally posted by Cory9584
right now im using 93 and im using an mbc set for stock boost. With the mbc the turbo comes up alot quicker so im thinking maybe it has too much power at too low speed? If that makes any sense

I run an MBC at 15 PSI and I don't get knock on 92 octane. Your car shouldn't be knocking, this isn't an issue of excess boost at low RPM. You sure you're not running lean or something?

Cory9584 · 11-21-2005, 07:27 AM

I should check my fuel systen out. The car also surges when you start it after its already warmed up. I have to check the injectors and regulator as the car sat for 12 years without running before i got it and the tank and fuel pump were completely tarred up so who knows about the rest of the fuel system. Is there any way to check it?

AaronM · 11-21-2005, 12:54 PM

Quote:

Originally posted by Cory9584
I should check my fuel systen out. The car also surges when you start it after its already warmed up. I have to check the injectors and regulator as the car sat for 12 years without running before i got it and the tank and fuel pump were completely tarred up so who knows about the rest of the fuel system. Is there any way to check it?

To check the injectors, remove them and watch the spray pattern.

If the tank and pump were shot, you need to have your injectors cleaned at the very least, more likely professionally rebuilt, quite possibly replaced altogether. Replace the fuel filter too. This is well beyond the abilities of Techron...

Aaron

Cory9584 · 11-21-2005, 01:53 PM

The filter is new, and im likely just going to upgrade to 55lb injectors in the near future. I think i may have found my problem today while fixing a hose. I realized the J boot was loose and pulled off without even loostening the clamp.

Cory9584 · 11-21-2005, 01:57 PM

Ill just have to try it now, and hope its better. If not new injectors may be coming even sooner

ae1969 · 11-21-2005, 05:49 PM

Are you sure its knock and not something else......

2nd gear........low rpm.........is not traditionally where I hear knock on the turbos.....

Cory9584 · 11-21-2005, 06:50 PM

It does it under load usually, but like i said it may be fixed but i have to wait for a dry day to realy try it. But before i was driving it easy and orogressively stepping on the gas and at maybe4000 rpm in second gear i heard something that sounded like a trumpet so i repeated what i did and it did it again. Whats up with this now, everytime i fix something another problem comes up. whats that sound like now?

Cory9584 · 11-30-2005, 04:03 PM

I think i found the problem today and its likely a clogged cat why it has no low end power because today it has gods of low end power and a new noise under the car likely from the cat. Ive been looking for a good reason to hollow it anyway