Got Knock then No Knock?

[KCODE]

Car was running great in November. Car set till now (I did start and run but no driving). Scanmaster numbers looked good. Took the car out made a pass 14.1 retard on Scanmaster???? Backed off adjusted the fuel pressure from 43 psi to about 49 psi off vacuum and made a pass no knock; made another pass 9.1 retard on Scanmaster. WTH is going on?????

 

[huntsg]

What MAF are you running?

 

[KCODE]

Stock

 

[Jerryl]

What was the ambient temp in Nov and what is it now?

 

[KCODE]

70; 50

 

[huntsg]

When I used to run a stock MAF I had similar issue. Sometimes knock and then sometimes none. My MAF turned out to be bad. If you have access to a known good MAF it is an easy check. What boost are you running?

 

[Jerryl]

70; 50

Here is what I'm thinking . .

If what you saw was the result of "real" kr . . .
Gas lost some octane, car was on the edge of detonation at time of storage, cooler weather (lean) and loss of octane is a double whammy.

That's my initial internet analysis.

 

[KCODE]

17

 

[KCODE]

I assume that means turn the boost down.

 

[pacecarta]

you have a tt chip
looks like you were lean as fuel hel;ped
you shouldnt need to adjust the fuel pressure
you can increase fuel in the chip,
cold air will require more fuel and will need to be adjusted for in the chip , what are your BLMS looking like
it could be you have a delivery issue , or an octane issue , what were your O2s when it knocked?
if o2s was low first increase fuel in chip , then hook a fuel pressure gauge to the rail and observe that the pressure rises and holds one to one while under boost

 

[KCODE]

you have a tt chip
looks like you were lean as fuel hel;ped
you shouldnt need to adjust the fuel pressure
you can increase fuel in the chip,
cold air will require more fuel and will need to be adjusted for in the chip , what are your BLMS looking like
it could be you have a delivery issue , or an octane issue , what were your O2s when it knocked?
if o2s was low first increase fuel in chip , then hook a fuel pressure gauge to the rail and observe that the pressure rises and holds one to one while under boost

Blms 118
O2 were around 750ish
Boost rose 1:1 (I have phantom 2 fuel and boost gauge in cockpit).

 

[NY87GN]

sounds like octaine issue or bad gas to me...

 

[KCODE]

I'll start at the gas first. Run it dry then change fuel filter and find another gas station with 93 octane.

 

[Jerryl]

Blms 118
O2 were around 750ish
Boost rose 1:1 (I have phantom 2 fuel and boost gauge in cockpit).

This is the idle blm cell, which dropped from the increase in base fp. (?)

 

[KCODE]

Yes

 

[MDavis]

Stock

I have a stock MAF you can borrow if it comes down to that.

I had a similar issue when an up pipe hose blew off.

 

[KCODE]

Thanks

 

[Rell87]

Buy a new maf/maf translator and a alky kit (single nozzle)

 

[KCODE]

Already have an alky kit (just have not installed). I was just looking at a MAF/translator combo.

 

[KCODE]

MAF/translator combo on the way. I've been reading a lot of good post on this. Fingers crossed.