Tuning a 93 3.4 Firebird

[robertisaar]

if both BLM and INT are at/around 128, and you are in closed loop, then that's it. there is a rich/lean indicator, but it's not helpful in this situation.

[tkoforpresident]

if both BLM and INT are at/around 128, and you are in closed loop, then that's it. there is a rich/lean indicator, but it's not helpful in this situation.

Okay, wait til it's in closed loop mode, watch BLM's and INT's as i lower fuel pressure.

Sounds good to me.

Since i won't be disconnecting the FPR vacuum hose while lowering fuel pressure, i'm assuming that once i do get it in the "stoich zone" that i should THEN disconnect the hose to get the CORRECT fuel pressure rating that is to be used, right? Because the pressure shown at idle is ususally 4-7 psi lower than the highest setting. (think thats right, just verifying)

[robertisaar]

exactly.

[tkoforpresident]

touchdown.

[ForcedFirebird]

So I guess you are going to try what I said after all eh?

[tkoforpresident]

So I guess you are going to try what I said after all eh?

lol now that i think about it yeah. Believe it or not, it didn't really sink in (how it was gonna work) until i sat there and thought about it.

(get the car to run right, and THEN you can set the BPC based on that... DUH )

some things take time to sink in with me John....

but you already knew that hahaha.

[60dgrzbelow0]

OK, so let's say i forget the "formula" for finding the BPC for a moment. If I were to start up my firebird with the 18.2lb/hr injectors (out of the 99 olds), let the car warm up to operating temps, and then raised/lowered the fuel pressure (probably lowered) til i got a "stoich" reading from Tunerpro (while i'm datalogging and looking at the dash values)... let's say the fuel pressure that it seemed to like was 37psi just for the sake of an example, how would i go about changing the BPC so that i could run the same injectors @ 43.5 psi while still staying at that "stoich" level? I think that question makes sense. Because as of right now some people are saying that my BPC is way too high and it IS running stupidly rich and that the correct way to set BPC is to keep scaling it back until it starts to lean out.

Any one have some thoughts for me on this?

thanks

Max...

Since its been said, "If you are Nearly Correct... You are Precisely Wrong!"...and since you are shooting for more precision here... I just double checked Stan Weiss' EFI Database Site and plugged in the P/N 17109826 for the 99' EFIs going into your Fuel Rail...and he has them charted at: 18.15 PPH

Just in case being exact counts in your stoichometrics...

[tkoforpresident]

Max...

Since you are shooting for precision here... I just double checked the Stan Weiss' EFI Site and plugged in the P/N 17109826 for the 99' EFIs going into your Fuel Rail...and he has them charted at: 18.15 PPH

Just in case being exact counts in your stoichometrics...

every decimal counts as far as im concerned.

Thanks for the heads up!

[60dgrzbelow0]

No Problemo...

Say Max.... With things being so God-Awful Cold up your way... and after reading some threads from Geoff (betterthanyou) on the problem of headers and the occasional necessity for using Heated O2 Sensors...is it possible that the pipes are cooling too quickly around your stock O2s to be able to function properly on your engine?

[tkoforpresident]

No Problemo...

Say Max.... With things being so God-Awful Cold up your way... and after reading some threads from Geoff (betterthanyou) on the problem of headers and the occasional necessity for using Heated O2 Sensors...is it possible that the pipes are cooling too quickly around your stock O2s to be able to function properly on your engine?

well i'm not sure about that. The coldest i've tried to datalog the temperature in the garage was a balmy 42*F

You do bring up an interesting point though with the heated o2 sensor and i wonder just how much one of those would help me as far as the driveability/tuneability of my car.

Maybe Isaac, Robert, Geoff, or John will put in their 2 cents on the matter but until i'm convinced i won't touch it. I'm so bad with wiring it's unbelievable. I wouldn't even know which power source to feed off of.

[robertisaar]

there is an article on-site on how to add one....

and with headers that only read three cylinders, i would call it a VERY suggested thing to do.

[tkoforpresident]

there is an article on-site on how to add one....

and with headers that only read three cylinders, i would call it a VERY suggested thing to do.

I have seen this article you speak of, which gave me hope of adding some heated 02's, but i'm not sure which 12v source to feed off of on my 3.4, since you only want it to get power while the car is turned on.

I think it was over at FTV6... we were actually discussing this. The sensors are around 40$ a piece IIRC that would be needed to make the swap necessary but i'll have to see if i can go dig up the part # again.

This again makes the importance of knowing which (one) o2 sensor is being used for my tuning so John if you could maybe do some snooping to find out, that'd be great, or if Robert you have a simple idea on how i can figure it out just let me know.

thanks

[robertisaar]

http://60degreev6.com/Computer/Miscellaneous/Heated_O2_Sensor_Install

i can come up with a simple method as long as you have a multimeter. or even a test light, now that i think of it.

[60dgrzbelow0]

Here is another article along the same lines...and actually written by Geoff Moore... The Man we all know, who is better than me... and... "betterthanyou"

http://members.shaw.ca/betterthanyoutoo/how-to/ho2s/heated_oxygen_sensor.htm

[robertisaar]

Here is another article along the same lines...and actually written by Geoff Moore... The Man we all know, who is better than me... and... "betterthanyou"

http://members.shaw.ca/betterthanyou...gen_sensor.htm

not a bad write-up.