adeihl

Hey guys... Although I am not a honda guy... I love reading the fourms and find some VERY knowledgble people on here... I would like to hear some of your advice..

I drive a 2003 Boosted I4 tiburon..

10:1 comp
t28
290cc
SAFC II
intercooled

When driving around and I decide to give it a goose the a/f's will go to about 12:1 all the way to redline....

If I get on it again... they will get to 11:1 untill redline..

If I get on it again.... they will get to 9:1 or greater till redline.

Any ideas??? All a/f's are read with the PLX wideband.

Thanks so much,
Andrew

Drew Peacock

Are you saying it does it in that sequence each time? If not then differing atmospheric condition will affect the A/F ratio..

adeihl

Yep... just like that.... with in min's of each run..... boost pressure is consistant as well...

I just cant think of anything...

Drew Peacock

Definitely a tuning issue I would assume its unburnt fuel from the previous passes.

Alstare

I'd say possibly everything heating up from back to back runs..

Since hotter intake temps will run richer, but not normally that much though..

I unno man, sorry..

adeihl

hmm.. Thanks for the advice guys... My data logger took a **** so I cant look at trims or IAT's...

Just trying different stuff with the SAFC....

lugnuts

I'd say possibly everything heating up from back to back runs..
Since hotter intake temps will run richer, but not normally that much though..>>>

correct.... but also consider the air temp correction may not be optimized... for example hotter air will have less density thus requirind less fuel for the same a/f ratio, truth i I would want this to some effect to prevent detonation from the hot air.

also, if this is happening from say 2nd gear to 3rd and 4th gear, then it is the added time the wide band has to read the actual ratio.....

Mase

I think you guys are failing to realize, that even if the car is getting hotter as the runs go on, its not going to change the AFR that much.

I'm dont know much about tiburons, i think something is going on w/ ecu. is it a map sensor or MAF?

unless, your wideband is going nuts on u.

beepy

When you hooked up the SAFC, how did you do it? Are you using the stock MAF sensor for the signal? If so, that could be the problem. Assuming that you relocated the MAF sensor to the vacuum side of the turbo, the MAF will read more flow than the engine is actually getting whenever the BOV opens. This will cause the SAFC to inject too much fuel, and can cause fuel puddling.

This is just a guess based on my experience with the Kia, which has a similar engine as the Hyundai you drive.

adeihl

Hey guys....

Nope I am MAP...

The BETA II ( My engine) was based off a late 80's design for the 4g63 mitsu engine.

I think it might be somethine screwy with the ECU as well... Is there any product out there that is a piggy back that adds fuel based on set a/f or PSI????

a few friends and I are trying to work on an SAFC hack for this purpose

Oh also.. I an running the MSD DIS II but I am not pulling any timing...

Andrew