Engine dead spot

02 2500avalanche · December 27, 2003

Well today my friend and I were doing some 0-60 runs with my truck and right at 50 the engine would cut out and sputter and struggle to make it to 60. My guess is that the engine is retarding itself in the timing department, or its lean and not getting enough fuel. It feels almost like the speed limiter used to be while approaching 100 before I got my superchips tuner. This is very strange because we did some 0-60 runs a month ago and the engine ran right up to 60 and beyond. Im gonna clean my MAF and see if that may be the culprit.

Alex

02denali · December 27, 2003

what rpm's are you at when you are getting to 60mph. is it in first gear still.what are your shift points set at. does the superchips read real time data. my mass air was not working correctly but it would still climb good.

02 2500avalanche · December 28, 2003

The rpm's were at about 4k and it was in drive and pulling along in 2nd gear. The shift points are the superchips one which are set in the computer program, you cannot change them. It shifts at around 4k from 1st to 2nd gear and the same for 3rd to 4th, I would imagine your small block would shift at a much higher rpm then my big block does so thats why its only at 4k when shifting. The superchips does not read real time data just diagnostic codes, Im gonna bring it down to my friends at the dealership and screw around with it with the Tech2 and see what I can find.

Alex

Butch 02 Denali · December 28, 2003

Alex, are you sure the shifts are set at 4k? that is way too low even for a big block. I would think you would want them at about 5k. The small blocks run best shifting at around 56-5800, the big blocks around 5-5200. The trick is to get the rpm AFTER the shift into the bottom of the power band of the engine.

As for the sputtering problem, uninstall the Superchips and see if it still does it.

Butch 02 Sierra Denali

02denali · December 28, 2003

sorry i didnt see that. 4k oops. something is not jiving there. 1-2 5200 2-3 5100. try those if you can change it. i do know there is a custom program section in the superchips. if you can go in there and changen it. you will also need to see where your limiter is set at. good luck.

02 2500avalanche · December 28, 2003

its usually more towards 5 but I dunno I was not thinking when I posted it, it pretty obvious being that it makes most of it power right at 4200:D Im not to worried about it now because I did a few blasts the other day and it had no problem reaching 60 with the pedal to the floor. After I install the cam I am getting ls1edit and bringing it to an f-body guy here in Mass who is going to tune it.