I just installed an adjustable fuel pressure regulator on my wife's 95 2500 4x4 (350tbi,4l80,4:10). This is a must have for any tbi user out there. The truck has a noticeable amount of more power. I got mine from Jet but any would be great. I hope this tread helps someone who is on the fence to step up to buying one. Eldogg Queen City Speed
That's a good first step. 14-15psi makes a dramatic improvement according to everyone who's tried. Some of those factory systems are closer to 9-10 psi. I'm considering running vacume referenced so I can go higher in full throttle without going rich at idle. I also just modified my ECM to upgrade to modern EEPROM chips and ordered all the stuff to start burning my own chips. I'm expecting good stuff. Still lots to learn though...
i got a question on the tbi issue my truck is a 93 2500 with a 350 i put a free flow exuast on it and it seems like the tbi is putting alot more fuel to it than it needs is there any way to fix that without changing my exhaust, i only have one o2 sensor should i mabey change that out? i have about 167k miles on it but the engine only has about 90k on it.
No clue on that, can't see how the exhaust would cause a rich condition. Normally, anything that improves the engine's ability to breathe will take you more lean, not more rich... Have you actually checked what the O2 is reading (VM or scanner)? Did the O2 move further back in the exhaust, or remove the cats? If so, it could be too cold there and may need to move up, or go 3 wire heated (if not already). If none of that pans out, it may be a bad O2. Maybe someone else will know more, or go ask on thirdgen.
Yes, it could be rich. The downside to doing an exhaust system is that the O2 sensor may not heat up properly to get the reading it needs. When this happens, the computer throws it into a 'safe mode' but doesn't trigger any check engine lights or such. It won't even show up on a smog inspection except for the fact the it's at the high end of legal emissions and usually just passes. The good news is that there is a fix and it's legal! First we need to determine what type of O2 sensor you have. How many wires are coming off of it? If it's just one (like my sons was!), then you have a non-heated unit. You can either go with a 3-wire setup (what we did) or 4-wire. The 2nd wire heats up a heating element inside the unit to bring it up to the proper temp. The 3rd wire acts as a better ground rather than trusting the exhaust system for the heating element. On the 4-wire system, the last wire is an improved ground for the O2 sensor (or something like that). I'll try to find the website that describes this better than me (possibly even corrects me ) and get it posted for you. Found it! http://www.cfm-tech.com/oxygen_sensor_tuning.htm
o2 sensor can you give me the brand name and number of the 3 wire and 4 wire to fit a 1993 gm 350 tbi, thanks.
We just picked up a universal 3 wire from Auto Zone for the same year vehicle. The factory put both styles on (the '95 at least) so it was a simple conversion.
