Studder under boost & rpm

Per Eriksson · Post by **Per Eriksson** » Sun Sep 03, 2006 10:09 am

I don't agree with you, it still leans some bins up to 20 points.

When I am in this type of situation tuning a car I make drastic changes in fuel just to try to get a hint of what's going on, If I don't see a change in behaviour I just change it back to what it was.
And with drastic I usually go +/- 50%.

S.Bretz · Post by **S.Bretz** » Sun Sep 03, 2006 2:28 pm

Per Eriksson wrote:Try to go a bit leaner on the fuel in the affected area and also get new plugs, plugs seem to be short lived when having problem with weak spark which I feel you have problems with.

What lambda do you use?

YEp...lean it out. The super rich mixtures it probably blow out the spark, and shows up as a lean spike. Try lowering the VE about 10-20%

millhouse · Post by **millhouse** » Mon Sep 04, 2006 6:06 am

I just replaced the TFI and after doing so, my AFR readings were pig rich. After leaning her out a bit it seams to have gotten better. I'm thinking my tune is on flawed readings. I'm going to relocate my wideband up closer to the turbine and add on a heatsink. Hopefully that will help out a bit.

millhouse · Post by **millhouse** » Mon Sep 04, 2006 6:56 am

Another thing worth mentioning is that the wideband readings now seem read different after different drives. After correcting for the pig rich readings, the afr's now are reading an uncomfotable 13:1-14:1. It runs better...but what's it's confusing the hell out of me.

millhouse · Post by **millhouse** » Tue Sep 05, 2006 4:40 pm

Alright, new update. I've changed the plugs and revised my afr table.

The studdering seems to have subsided...for now. The dips are still shown in the rpm's though. As I said too, my AFR's are scaring me a bit. They are spikey and a bit on the lean side for running 8 lbs of boost. Im afraid to richen them up however at risk of re-creating the problem. I'm currently not detonating...atleast not that I can tell.

Any and all help would be appreciated.