Hypertech has lots of good parts for that truck. Theres some sort of intake bath tub that looks like a stainless bowl with the bottom cut out that works great for funneling air under the TBI injectors.

 

Naw, it can get better. I've put some 355 and 383 TBI engines together for people.

My old 383 TBI engine was knocking out 15city and 20mpg hwy.

Your tune is off...are you datalogging for him to see what he needs to fix?

 

Yes I have sent lots of data to him. Do you know of a good tuner by mail? I am seroiusly thinking about either putting the engine back stock or a 4.8/5.3 transplant.
Engine specs:
stock short block rebuilt everything is std.
Camshaft is from a 1995 lt1 camaro
Heads stock 96 up vortec
Intake GM vortec to tbi with egr, throttle bores are 2"
50mm tbi with reconditioned injectors, 18 psi spring
fuel pump changed to walbro for the increased pressure.
intake noise suppresor has been removed
stock 96 up exhaust manifolds
heated o2 sensor is in the y pipe just before the high flow convertor

I have checked the fuel pressure its 17-18 psi. Have adjusted the timing from 0 to 6 deg.
No improvements in the fuel economy, as far as preformance goes it runs great.

 

Ok...first off, your o2 sensor is just before your converter(passenger side about where the crossmember is for the tranny?). If that's the case, move it more toward the exhaust manifolds. It may not be getting a good reading where its at..the narrowbands are really particular. Do you have a wideband to hook up in the exhaust? Widebands help tune a lot more precise.

Exhaust manifolds are restricting that engine but I'm sure you know that.

Where are you located?

 

The o2 sensor is in the factory location, just after both pipes come together. I removed the y pipe form a 93. The reason I installed it there was the factory 96 drivers side exhaust manifold was not drilled for the o2 sensor. No I do not have a wideband o2 sonsor.

I really do not want to install headers. Most of my driving is 2500 rpm or less.

I am in Missouri, close to Kansas City

 

In the 1990, it was in the driver side manifold. I've always put mine more toward the collector on one side of the engine. Two sides of the engine is hard to tune for b/c both sides of the engine doesn't flow, need the same amount of fuel, etc.

If you want to keep the manifolds, you can port/polish them out.

 

I will try to explain it a little better. The factory 92 exhaust manifold did have the o2 sensor in it. The y pipe was cutup and I replaced it with one from a 93 e-cab which had the fitting for the o2 sensor. The 96 vortec exhaust manifold on the drivers side did not have the o2 sensor in it but I used it for the egr tube. This is why I put the o2 sensor in the y pipe.

I was thinking about changing out the 96 manifold and put the 92 on it and put the o2 sensor in it. Would that help?

I bought a new AC-Delco 3 wire o2 sensor when I started this project.

Thanks
Kevin

 

If you wanted to get rid of the EGR..that would work. If not, just closer to the collector.