i thought at wot the computer ignores the o2 sensors....may be wrong but im pretty sure o2 sensors calibrate part throttle to 3/4 throttle fuel.

 

I'm not sure how it is shown on Datamaster, but in AutoTap reading the O2's they are constantly changing, they don't hover around 450, they are always going up and down as your accelerating/decelerating. I log my ST and LT fuel trims to see where I'm at in regards to the computer adding/subtracting fuel. From reading the forums the computer should go into PE mode when you are WOT, but if his injector duty cycle is 128% then he is for sure has a problem with fuel delivery.

 

read the thread

 

Fuel pressure at idle is about 35, held throttle to 3k and pressure dropped to 30, quick WOT dropped down into the 20's, couldn't drive it attached because hose was too short. Idleing with vacuum of regulator it would jump up to42. Guess I'm going to change the pump.

 

how short was the hose? Most people I know end up duck taping it to the windsheild down by the wipers and cruise around. I would imagine that if it's that low parked then when you put a load on the engine that it's even worse.

 

Anybody else tired of these smartass kind of posts that add nothing? I asked the question and I meant it. Some years, maybe the '95, only came with 22 or 19s or something. Geesh.

 

iirc, all fbodys came with 24s from 94 on up.

either way, stock injectors are way too small for his setup. dont get pissy because the question was already answered.

and it still added something, pointed out that they are stock injectors. your post however did not add anything, neither is this one that I am typing right here. Take it to pm if you have a problem....

 

Getting worse. Well changed the fuel pump today, took it for a ride running great, go to pass someone floor it, drops to first and it ran horrible so bad it wouldn't shift until I let off the gas. Tried to do a log and it would barely run. DTC 55 lean condition. As soon as I go over half throttle it stumbles real bad even idling in the driveway. In fact if I hit the gas in park and it stumbles it will come back down and idle at about 500 rpm's and barely stay running. Guess I'm not going to make it to the track tomorrow. Starting to hate my car.

 

Get this, my brand new fuel pump lasted 20 min. So I had an old gas tank and pump in the backyard from a v-6 that was out in the weather for three years and had 120k miles on it. Put it in to confirm new pump was bad and it started right up and ran, so I said off to the track. With that rusty old v-6 pump the car ran 12.8's all day. Go figure. So I guess that confirms that my top end problem is all fuel related. Oh by the way don't buy a Tre performance pump unless you only need one for 20 minutes.

 

Damn that sucks! Why did you not go with a Walbro pump? Everyone here runs one for the most part and they perform great.

 

Aren't Walbro's pumps just rebranded Aeromotives?

From what I've heard, even those aren't the best. If you want the best, you need Bosch.

 

I don't think so.

Walbro's are pretty good, Bosch is a great pump from what I've heard too, but then again, how much you looking to spend. From what I can remember when looking at Walbro and Bosch for my projects, Bosch was around $30-50 higher. It flows more of course, but the Walbro flows enough for most setups already.

 

Finally I got my Granateli (Walbro) fuel pump kit in today, car pulls harder up top now. Won't be able to get to the track till next week but should run a bit faster. Did a data log and the injectors are only running at 109 at 6200 RPM's instead of 128 so I guess the next step is bigger injectors. Anybody want to make a suggestion on what size I should get? Should I get larger than needed in case I do more mods down the road?

 

Paying $30-50 extra for OEM-grade reliability (which you get with Bosch, but not Aeromotive or Walbro) on something as important as a fuel pump wouldn't even make me blink.

 

look at some 36s if you never want to upgrade again as long as you plan on running all motor. I have 30s on my car, and I think I may be pushing it.