Tuning a 93 3.4 Firebird

[tkoforpresident]

Don't make any changes at first. Start and log the car with the stock FP and tune, log the entire session. THEN make changes - one at a time.

don't even change the BPC or IAC steps??

remember my injectors aren't stock for a 3.4 (19 rather than 17lb)

[ForcedFirebird]

If anything at all, watch your datalog guages on your laptop as you are adjusting the FPR and get it idling at stoich or so.

You can have 24# injectors, stock tune and stock motor and adjust the fuel pressure to make it run. We need to start at the basics and get the car to idle so the battery will charge and you can get a clean log.

[bszopi]

We need to start at the basics and get the car to idle so the battery will charge and you can get a clean log.

QFT!! One of the keys to tuning is baby steps. Don't try to do too much at once, because you'll end up making things worse. I think you now know that.

[tkoforpresident]

Wow, so your saying to leave everything as is and just tone down the fuel pressure til it idles correctly?

Hey man if you'll stick with me i'll do this thing ONE step at a time.

btw, how do you view the "gauges" while datalogging. Every time i select them they are always minimized and i can never seem to get them to open up full screen to look at?

[robertisaar]

the dash screen in V5 can be sized to however large you need... just drag the top bar, and shrink or close the other menus.

[tkoforpresident]

the dash screen in V5 can be sized to however large you need... just drag the top bar, and shrink or close the other menus.

but what about V4?

[robertisaar]

same concept. just with less guages...

[tkoforpresident]

ok, i'll give it a go!

I AM however going to change my bpc to 210 regardless of what John thinks

And what about the oil? should i give it a change? It's been in the car for 4 months or so and it seems to be full of gasoline....

[60dgrzbelow0]

Max... You already know how I feel about taking any chances with lubrication. If those 19 PPH EFIs were dumping raw gas into the cylinders ...thinning the oil and breaking down its viscosity...then it's kind of like your girlfriend telling you that she's just a teensy bit pregnant... (what's the difference between a pregnant GF and light bulb? You can UNSCREW a light bulb....). If you are well past any New Part Break In periods... then change the Oil and Oil Filter (I know how much you like the expensive K&N flavor... Good Man!) and its one less thing for you to worry about while doping out your Toon.....Oh...and please tell me that you are backing the car completely out of the garage when all this is happening... Even with the back doors open...the O2 can become depleted in a confined space pretty quick and replaced with CO...and I've seen too many dead people with beet red and pink cheeks sitting in parked, idling cars to stress why it worries me...not to mention how hard it is for the car to breath and idle/run properly as well. Just spend about ten bucks on a Carbon Monoxide Detector and set it on your work bench. If it goes off while you are "Tooning" ... then you'll know what to do.

[tkoforpresident]

hahha don't worry Bob i'll be careful. Unfortunately (or is it?) there is a 2001 Corvetted parked DIRECTLY behind my firebird so theres no moving it at all. In fact it will be a huge pain in the butt to change the oil & filter but i'm gonna squeeze my fat ass inbetween the Buick Regal Turbo, 93 Camaro, and 01 Corvette that fill the remainder of the 4 car garage without scratching any of them up.

[tkoforpresident]

OK, so here's what i'm going to do.

I'm going to restart with the original .bin which seemed to have my car running the best so far (oddly and annoyingly enough).

I am going to only adjust the BPC to start with and i'm going to put it at 43.5 psi (stock)

I'm also trying to find out what the true lb/hr rating is on the injectors from a 3.8 firebird/camaro which is where i got them from so i can be more specific in the BPC calculation.

I'm going to put a couple gallons of fresh fuel in my tank as well since the stuff in there is a few months old and has FUEL SAVER in it.

I'm going to replace the o2 sensor (the one that is being used that is)

As soon as i start the car (God willing) i'll set the pressure at 43.5, then turn the car off, do an idle relearn (God willing again that the car doesn't stall in Drive)


then i'll let it warm up and take a datalog. Then i'm going to give it to one of YOU guys to take that data and make some adjustments for me on the .bin since apparently i suck at it!

max

[tkoforpresident]

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 queestion 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

[tkoforpresident]

ok i just had a small revelation!

Using my earlier example (that the 18.2lb/hr injectors running @ 37psi is a "stoich" setting) than i can run those numbers through the witchunter calculator to see what kind of lb/hr flow i'm actually getting with 18.2lb/hr injectors @ 37psi and then using that flow # run it again through witchunters calculator but @ stock 43.5 psi, thus giving me a correct lb/hr rating to run through isaac's formula again and giving me in finishing, a new BPC # that is correlated to the raise in fuel pressure from 37-43.5


Eh?

I think that makes sense...

[robertisaar]

find what pressure it likes (as an example let's say 35)
run it through the witchhunter calculator to see what it computes to (16.2lb/hr at 35PSI)
see that there is a 12.3% change from 18.2 to 16.2
change BPC by 12.3%

[tkoforpresident]

find what pressure it likes (as an example let's say 35)
run it through the witchhunter calculator to see what it computes to (16.2lb/hr at 35PSI)
see that there is a 12.3% change from 18.2 to 16.2
change BPC by 12.3%

simple enough, thanks!

a word however on the "stoich" part. I haven't actually seen anything in TP while datalogging that will let me determine when it's at or near stoich. Where is this located? Am i to just be looking at the BLM's until they are all at 128? or is there actually something more simple that says either rich/lean/stoich. What should i be looking at?

thanks!