well i had the same problem with my camaro and u have more potential power but its not there and runs real crapy at lower rpms because the computer does not know you have these upgrades. and then want to run at wide open throttle all the time.
from the way u explained it i would suggest looking into a custom made chip.
Also when the car is runing go look at the injectors and see if it looks like you are getting way to much fuel (or in my case it just spays so hard the it hits u in the face =p)
but this is my best suggestion for you


you could also pull out your prom first to see if its the stock one or if its a aftermarket and stay away from chips like stage 1 or 2 etc have a custom one made by jet chips might be a lil spendy but should get the job done.

 

ok gentlemen i have checked everything again except the egr because i have no vacuum pump and the charchole canister was also not checked. My father checked all the sensors about 4 months ago and he didnt find any bad ones, even the egr checked good.

i checked the puter and my lotto numbers were

24. vss (doesnt pertain to my problems)
32. egr or ecm (the ecm is new with stock chip) replaced 2 months ago for no good reason.
45. o2 running rich (this is getting effected and not the cause)

should i replace the probably good egr or go ahead and get the chip? im leaning towards the custom chip. tbichips.com or jetchips.com?

 

also i belong to supra forums and supra mania, they are filled with negativity and high and mighty BS. thank you for helping without trying to step on me. I guess thats what i get for not buying american.

 

try this place.
http://www.pcmforless.com/index.php

 

i did but they said they dont make them anymore. They told me about tbichips.com

 

San, it has been my experience to check all the "cheap" fixes first. Sounds like you have checked a lot of different things but I would also check all ground straps. They can cause many different issues. Then I would check the fuel filter and the throttle position sensor on the tbi unit. The hesitation while accelerating sounds like an issue I had with my '89 camaro, turned out to be the throttle position sensor. Lastly, after all those upgrades I would consider the custom chip. Hope this helps!!!

 

thanks for the input marc. Grounds are a great place to look that most people dont think about but i have already had some grounding issues in the past and have already gone threw the whole engine bay and cleaned/replaced all ground connections. the tps has also been replaced and checked. The truck maybe has 2k on it but we replaced the fuel filter 2 months ago anyway but that made no diff.

guys i really appreciate your input but i think i have run out of things to check. My father and i think the chip is the last ditch effort to save this fuel injected motor after that were gona rip everything off and throw on a carb.

 

have u pulled the tb injector/s and cleaned it/them. could be gunked and sticking. also have u been able to check the fuel pressure at the tb. i think u said u replaced the map, im out of ideas. it almost has to be a bad wire somewhere.

 

the injector spray is good and plenty. im ordering a chip tomorrow and i will let yall know what happens. keep your fingers crossed!

 

I know how you feel chasing problems like this is tough. I had an engine built for my '89, a 388 stroker, that I tried to run with the tbi setup. The engine started and idled just fine and would even run under light acceleration. But when given full throttle or even part throttle it would fall on its face. I tried to tune it and use larger injectors with no luck, I threw in the towel and ordered a new intake and a 625 Demon carb. I thought the tbi would be better for response and driveability but the carb runs great.