Knock, knock....

2500avalanche

2500avalanche

Well-known member
I was hoping for some help.
So,I do have a scanmaster G on my typhoon. I have 60lb injectors TT chip, 20g turbo, and anytime I am into boost, I am getting up to 5* of knock when at WOT. Very frustrated. the truck runs great otherwise. I have read a lot on knock, but I do not know where to start. No knock under normal driving, only while in boost. New wires, plugs, and distributor (entire thing). My truck I make sure to take care of, but this is very frustrating.
Any hints, I would appreciate.
 
Mephisto

Mephisto

These trucks are cursed
What gas are you using? 5* at WOT on 91oct is not that bad. I haven't seen a ton of these trucks in my tenure, but I don't think I've seen or heard of any truck that didn't have some degree of knock on pump gas. I'd still get 1-2* on 101oct in my old syclone.
 
wildphil

wildphil

I Love My Ty's
While 5 deg is not to bad. You should be able to do better. But you do have to find the cause. Could be a lot of things to rule out. You could try a little better fuel or a little less timing. Those would be two things I would check first at a WOT knock. KR is one of the hardest issues to find IMO.
 
2500avalanche

2500avalanche

Well-known member
Yeah, it is frustrating! I have gone internal to change the degree under boost in the TT chip. Seems not to change it. Changed fuel, nothing changed either.
 
wildphil

wildphil

I Love My Ty's
Was the fuel you tried racing fuel? I traced a KR cause down once that was the clamp on the back of the head securing the fuel line being loose enough to rattle. Only seemed to be a problem under acceleration.
 
S

Sparkz#0535

Member
Get a few gallons of 101 or 109 no lead and mix it in when you have a low tank .... .go make some pulls and see if you have less knock. Got to find out if you have real knock or false knock
 
IGottaSy

IGottaSy

Active member
How did it run with race fuel?
I have noticed I get some knock if I start boosting on a higher gear (OD going 40mph as opposed to downshifting, for example)

dirty fuel injectors, downpipe clearance issues, loose metal parts, worn out distributor gear could also cause this. How is the A/F ratio when knocking?
 
2500avalanche

2500avalanche

Well-known member
I am trying to find some race fuel. no stations close to me... Used to be one about a mile away, I was spoiled. That is the other issue, I do not have a a/f ratio gauge. I have to get one. Fuel injectors new (60s) TT chip, DP clamped well, but Cat does rattle (internal), Distributor brand new, plugs/wires brand new
 
proptop

proptop

Donating Member
Sir,
Have you checked your TPS readings at wide open throttle? Truck off, key on and cycle the foot feed/gas pedal while watching the scan master. I would be curious to see if the TPS voltage is low on the big end.
Bob
 
2500avalanche

2500avalanche

Well-known member
Will check the TPS today, also will check the timing when reving, have to get some help with this from Aeroking, he set my timing
 
IGottaSy

IGottaSy

Active member
Is the engine pretty clean around spark plugs? Sometimes you can get bad wires even when they are new. Check them in complete darkness for spark arching. They shouldn't cross each other.
 
proptop

proptop

Donating Member
Sir,
TPS is in range. Is the return line hitting the fire wall of the truck or as Wild Phil mentioned is any thing moving or rattling around that could be setting the knock sensor off?
Bob
 
syclone0517

syclone0517

Member
You mentioned you have 60 lb injectors but did you upgrade fuel pump and fuel pressue regulator? If its leaning out on the top end its gonna knock. I'd be checking fuel pressure on hard wot acceleration
 
You must log in or register to reply here.
Top