Ok I did the ultimate TBI mods, including the fuel pressure regulator.

I obviously cranked the fuel pressure too high resulting in a extremely rich start up/chug smoke etc.

When the ecu starts hittng up the o2, the ses light pops immediately the ecu compensates, and it starts running great.

I haven't pulled off the TBI to make it run right yet.

My thoughts.
At current obviously my fuel pressure is too high causing a rich condition. The stock ecu is expecting stock start up conditions, and cannot allow for my intake/fuel mods without reprogramming. So at this fuel pressure with these mods I will not be ble to smooth out the warm up without a ecu reprogram. Am I on the right track?

When the ecu hits up the o2 sensor and things start working(about 2 minutes), the idle smooths right out, and the mixture as well resulting in a bit more power than stock form, but an immediate ses light.

So kinda of, in my head I am thinking that I could do all the intake/fuel mods that I want, but no matter what I do the ecu is going to try to put the mixture where it belongs. Basically negating, or making useless any mods I do to the inake/tbi.. am I somewhat right?

Or is it possible when I crank down the fuel pressure I would get a little more power from the mods? I maybe just added way too much fuel for the ecu with my tbi?

Could we perhaps get some othes good/bad experinces with their tbi ultimate mods in here, opinons? maybe make it a sticky?

Anyone coming here is looking fomr more power usually, and more power for no, or less money is a mod we all want to know about and do. I read for about two weeks here, searching everyday before I had enough info start. It could save a lot of "Ultimate TBI" threads and answer a lot of questions before their asked.

 

You need to turn the pressure down then. If it is running too rich you are probably loosing more power than you gained by doing the ultimate tbi mods. Running too rich will cause a loss of performance in any engine, tbi or not.

 

Has anyone made or found a tool that will fit underneath that injector tower so you can adjust the fpr without haveing to take off the tower ? What a PITA
Turning down the fpr is first on the list, thanks.

 

your darn rite on that one too much can hurt. i was running as rich as possible (my old port-injection fuel pump was giving it 46psi) and didnt even know it, except fuel economy suked i had a full tank and what little i drove it about 15 miles between that and just starting it-it was gone.

 

turbo city makes an adjustable fuel pressure regulator for tbi which has an extended screw with a grippy surface at the end that enables you to adjust it without removing anything with just your fingers.

http://www.turbocity.com/TBIPowerMain.htm

 

Anyone else have any comments or experiences good or bad they would like to add here? I would liek to gather as many Ultimate TBI experinces as I can to learn more and share thtat with the other people following these posts.

 

Ive only done the ultimate tbi mods where i open up the top of the tbi i havent yet adjustade the fuel pressure im wating ti buy a vaccum adjustable fuel pressure regulator the best i think.Also ive done it for about 9 other people and they havent had any problems with the mods.Ive noticed a top end difference.Alot espically if i floor it from about 35 m.p.h.

 

hyey how hard is it to do the fpr thing in the tbi?any pics and what tools do u use?

 

If you had ground a slot into the shaft... then you canchange it without taking it apart.. all you need is a 2-3 inch screw driver..
as for miacamaro305... look in the tech articles of this website... you'll find it and alot more.
I have done all the mods except for grinding down the throttle plate shaft... I think that will make some nice gains for me... I dynoed my car yesterday and is at 292HP and 402lbs torque... and I'm still running the 305 tbi injectors too...

 

http://350.streetracing.org/tbi.htm

this will show you how to make your fpr adjustable, it's fairly simple with a good dremel. J

 

how did u managed to get so much power of the 305 tbi and you said the stock injectors

 

It's a 350 with 305 heads and flat top pistons and a zz4 cam... compression is about 10:1.

 

i did the regulator mod today.......i moved the tab down about 1/8 of an inch.Was very simple.....instead of drilling anything out i just used a pliers and turned the end of the regulator breaking the spot weld free letting the adjuster turn.Seems to run a little better at part throttle now......but not as good at WOT....was quicker before mod.
oh yeah...all the gaskets broke when i opened the lid of the pod...Avanced Auto had the gasket kit 47 bucks



89 305 TBI RS