hi guys,

this car has been rebuilt with a 350 motor bored .030, i kept my 305 heads and planed them .010, stock crank new 10/10 turned, RV CAM Elgin 923, 305 TPI, upgraded TB to 52mm with air foil, went to bosch 24lb/hr.

so i had ed wright do my chip at fastchip.com and they are great people. I was way overfueling the car, i have my fuel pressure at 33psi currently, ed had some wrong info i gave him on the MAF, he thought i had pulled the heat sinks but i had only pulled the screens. Also the CAM was off, so she was running super rich.

anyways, i got the new chip and he also told me to not run bosch platnums, so i changed the plugs with my SLP headers still on, YEAH!!! i was happy about that and went to autolites.

Here is my question.

The car seemed to have more power with the other chip, he has pulled alot fuel out of the mix, my air/fuel guage was green alot before and is now running in yellow which is where it is suppose to be.

i have a 160 degree thermo, it was 0 degrees out, the chip is new.

question 1, the 85ecm has some learning capabilites i believe from my research on gm port injection, is the car learning the fuel mixtures now? block learn and integrator?

I only took the car up the road, 1 mile, but she seemed doggy.

my fuel pressure is set at 33psi, of course i am gun shy about fuel pressure with the way she ran before.

the motor only has like 50 miles at best on it.

i warmed her up idling for an hour.

Do i go to computer for bln's, air flow, etc.....
Do i bring fuel up?
Wait for a warm day and try it again? it was 0 degrees very cold and i heard you loose power in very cold weather.

any comments for me thanks.

the car sounds good, i would just like as much pop as i can get out of her.

 

I'd ask Ed what he wants you to set the fuel pressure at. I assume you pulled the fuel pressure way down to help offset the overly-rich chip tuning before. Now that the chip's been fixed Ed might want you to put it back up around 42 PSI like stock.

Don't rely on the ECM to learn it's way to perfection for you. It only learns under certain circumstances and only from idle through part throttle- not much learning going on at WOT because the ECM ignores the O2 sensor at/near WOT. It also throws much of that learning in the trash as soon as you turn the engine off and remove the key (try it some time- you'll see all the block learns and integrator values go back to 128 every time you shut down, remove the key and restart.)

Tune your engine with ONE person. Don't keep second guessing your tuner unless they have proven themselves to be idiots or have run out of ideas. I don't think Ed is either of those things.

 

that is excellent advice and is what i am doing, i am just trying to get as many opinions as possible for this slightly modified car. maybe she will end up impressing the heck out of me, my fingers are crossed

At 05:01 PM 1/22/2005 EST, you wrote:

>>>>

fastchip.com <john>



i read an article on gm port injection, it seems like my computer can
learn a little, but it is rom memory so i am confused how the ecm will
handle the integrator and block learn.



will the car learn a little with this new chip?



fastchip.com <john's> response to me FYI


The car will learn for up to 30 miles that what your fuel trims are block
learns make large changes and the integrator makes small changes, they
can adjust more than what you might think, that is how they adjust for
different weather and climates. Let me know how everything works out.
Those air fuel guages that plug into your factory O2 sensors are not very
accurate, be careful trusting those, they are mostly for looks.




John

 

John's right about the A/F gauges. They're great for telling you rich or lean, but they're not accurate as to HOW rich or HOW lean you're running. You need a wideband for that.

He has the BLM/INT thing mixed up though. It's not big/small changes, it's long-term/short-term changes. The INT adjusts fueling by what the O2 reads (short-term, rapidly changing adjustments,) and the BLM adjusts it by what the INT has done over a period of time (long-term, steady state adjustments.) They both have the same capacity to add/pull fuel, it's just a question of how fast and for how long they do it.



Find out what fuel pressure they had in mind when they burned the chip, and set your car to match. You'll have better chances of the fuel curves being close that way (although it'll never be perfect with a mail-order chip...at best it's an educated guess.)