it might be rich

84ttype-hotair

New Member
hi and thanks
when crusing my scanmaster shows 750 800 then goes to 100 then to 70 then back up to the 750 800 at wot its in the 700 range and no knock i have 32# injectors a 3" maf and a translator pro at base its set to be 2" lean and at wot its set at the same is the car rich and then leaning its self out the fuel pressure is set @43# with the cap off any help will be get thanks its a 87 set up on the car thanks
 
its hard to tell what its doing. you really need to stop using 02's to tune. you need to get your self a wide band setup to see what she is really doing.
 
When cruising its supposed to cycle back and forth from lean to rich. The vehicle is in closed loop and the ecm is trying to achieve stochieometric (14.7:1 A/F ratio) Dont worry what the o2's are when cruising. At wot is when the vehicle goes back into open loop and using fuel enrichment to achieve more power. I use a wb so I cant really tell you what to look for as far as 02 mv but from what I heard its 700-850mv with a butt load of variables (ie o2 sensor age, accuracy, ect ect.)
 
thanks for the help
so what should i been looking for?

I too suggest a wideband for tuning. Its so much more consistent and reliable. My scan master reads in the .740-750 range around 11.3:1. It does funky things when hot though and i dont even look at it much since i run a wideband LM1 in the car at all times.
 
i always tuned for high 790 with the 02 sensor but that can still be way rich. the last time my car was at the track and i was still tunning with 02's the car was around 810-820 range. that has to be pig rich but you cant tell unless your running a wideband.
 
i always tuned for high 790 with the 02 sensor but that can still be way rich. the last time my car was at the track and i was still tunning with 02's the car was around 810-820 range. that has to be pig rich but you cant tell unless your running a wideband.
Exactly and that can be 3 or 4mph!
 
3-4 mph is huge. i have a WB waiting at the house for the new motor i cant wait to start tuning. I was running 810-820 range up at the WCN and ran a 12.6 @108. thats really rich from what i have read 795 O2's is around 10.3 to 1 and 785 is around 10.5 to one so you do that math where 810-820 would be. if i wasnt running so damn rich i could have pulled off a very low 12 around 111-112.
 
3-4 mph is huge. i have a WB waiting at the house for the new motor i cant wait to start tuning. I was running 810-820 range up at the WCN and ran a 12.6 @108. thats really rich from what i have read 795 O2's is around 10.3 to 1 and 785 is around 10.5 to one so you do that math where 810-820 would be. if i wasnt running so damn rich i could have pulled off a very low 12 around 111-112.

On the chassis dyno with the engine that was in the blue car i picked up 38rwhp going for 501 to 539 by leaning form 10.2:1 to 11.1:1. The WB makes this a 5 minute tuning change.
 
i was probley running in the 10.0:1 if not in the 9's. If i would have know what i know now i would have Leaned her out and bam that thing would have pulled like crazy.
 
Back
Top