Scanmaster jumping on initial throttle.

[85HOT-T]

Ok my scanaster will jump tp 2+ degrees when I first go to WOT for a second or two then drops to 0 degrees through the whole gear.

Why is it doing this?

Is this normal, or is it safe evem though it falls right back down to 0?

One time it jumped to 8.2 but again fell right back down to zero.

Any input would be great,
Thanks,
Matt

 

[suicide six]

With car off and depressing pedal does it also do this? Never noticed mine doing this.

 

[85HOT-T]

I was thinking, could this be from a bad engine mount, or something hitting during the initial acceleration.

 

[87geeinn]

It sounds like a normal Scanmaster to me in that the knock sensor is picking up knock on the shift but since the Scanmaster updates every 1.5 seconds. It can take 3 seconds to disappear on the screen. Ever count to 3 under WOT? Seems like it takes forever.

HOWEVER, I've never had anywhere over say 2.0 counts at shift points though. So I agree with 85HOT-T in that you may have something loose or worn out in there causing false knock.

 

[85HOT-T]

Ok I was doing some testing last night and he scanmaster is not jumping anymore. I cant figure out why it did that. I guess it cold have been shock load or something? These scanmasters are great, I was affraid to turn up the boost before I got one. Now I just keep turning it up and up and up. I need to put an aftermarket boost guage in still, but I rhinkI am hitting over 17 lbs, where before I wouldnt go over 14.

Oh one more thing, everyonce in a while I will get an 02 mV of around 680 690, but most of the time it is 730s-40s. Is this ok? I dont want to trun up the FP cause It runs rich most of the time at idle and cruise. Then again I have a translator so I guess I an adjust.

 

[mcponch]

mv volts

as far as your mvS. if you get no knock at this range. its o.k. people are going to say its to low. should be 750. 800. STILL.... I SAY IF NO KNOCK, on the shift and . no knock in high gear, let it roll. FRANK.

 

[VadersV6]

Wish I knew what happened to my car. I used to be able to run 89 octane with 17-18psi with 25 to 27 degrees total timing with under 1 degree of KR. And that was with stock heat range plugs! Now I can only run 14psi with 21 degrees timing on 91, with plugs 2 points colder! Makes no sense. I also noticed my PCV catchcan has to be emptied every other day now. Something bad has happened. Anyway, Ive always shot for O2's in the low to mid 800's. That was the only way to keep the knock demons away.
You shouldnt have to adjust FP so that you get good O2's at idle and cruise, but low WOT O2's as a tradeoff. Do you have a translator? I have mine set to 10% lean at idle, cause it has to be. I run rich at idle just like you. But there is no way I would run low FP and end up with a lean WOT number just so my cruise and idle numbers are ok. Besides, WOT and cruise fueling arent even connected. Adjust your FP to get good BLM's and then find some electronic means of leaning it down for idle and cruise, and adjusting WOT O2's. The extender chip works awesome for this.

 

[mcponch]

tun up

i also have to run lean. i have the ext-plus. also. frank.