VE coming out way over 100

[Mastiff]

Changing them is on my list. I can't imagine plugs alone could cause all this, but what do I know...

[EagleMark]

Yeah those 2 sponges are for the regulator cup bottom to seal off air from being drawn into TBI. I don't recall those 2 silver rod things? What were they for?

I've had 2 cheap liguid fuel pressure gauges from Summit and never an issue hot, worked on a few and same thing. But none on a Camaro so maybe it's a Thirdgen thing?

If your gauge is 0 to 50 and reading 11 it could be close enough. You understand why a 0 to 15 pound gauge would/should be more accurate because of the amount of swing...

IIRC you had an inline pump and same pressure or same lean BLM? But we saw bubbles in clear pre-filter pump and beleived it was sucking air. Now you changed out to newer style tank with in tank pump and still have same fuel pressure and lean BLM?

I try to help a lot of people and loose track so forgive me... if all that is correct what part in middle of fuel system is still the same? Could there be a pinched line on feed side? Pump is now in tank so there's no sucking air between tank and pump... I'm assuming there's no issue with intank pump installation... in-tank pump ground is good... tank was clean as you just put it in...

So on to what dave w and I mentioned with O2 sensor. I would pull it and see if it is sooted up black and then test or replace. Here's an article on how to test:
http://www.gearhead-efi.com/Fuel-Inj...-on-O2-sensors

and as mentioned pul a couple plugs and see if they are white. If your that lean they will be white. Tan is good. Black is rich.

At this point I'm assuming again you have no cylinders not firing (miss) and no exhaust leaks before O2 sensor. Would have to be a big vacuum leak on intake side messing up O2 reading... with that said I would pull all four plugs on O2 sensor side of engine...

Wish you were closer and I could get my hands on it, I actully enjoy diagnosis...

Any other ideas I'm missing here guys?

[EagleMark]

Changing them is on my list. I can't imagine plugs alone could cause all this, but what do I know...

It's not the changing it's looking at them/reading them!

[Mastiff]

You are correct about the things I have done. The only thing that is the same on the fuel feed side is a section of factory steel line on the frame that I've been using. All the rubber line is new and the filter is new. If you recall, it was a cheesy carb filter with air in it and now it's an EFI filter (factory style 1991 K5). I'd be surprised if the plugs were crazy, but I'll look. The computer is trying to pull it in, and it runs okay except for terrible hesitation on acceleration, especially cold. If not for that, a person wouldn't know anything was wrong without reading the numbers. So, on my list so far:

1) Try the unmolested ARJT bin
2) Try just putting the 25 back in 0 RPM
3) Check the plugs
4) Check the O2 sensor
5) See about getting fuel pressure into the cab
6) Buy EBL for better overall instrumentation - ha!

[EagleMark]

Since you've done about everything on fuel side you should inspect that steel fuel line for a pinch. Your getting enough fuel to get close pressure and BLM at idle close but goes downhill when it needs more fuel. If it's got a kink or pinch or damage from off road it will limit supply.

Computer is trying to compensate for something?

I'd never try and talk someone out of EBL but it will not fix a mechaical issue either...

[EagleMark]

Do you have a data log from TunerPro? If so post it up...

[gregs78cam]

This is sounding like a fuel supply issue. Almost like you enough for idle and maybe cruise, but when you ask for more, it's not there. That could be cuased by what you mentioned earlier about air in the fuel line. A couple of things that could cause this....1)If the return into the tank is aerating the fuel right around the pickup, the pump will pick it up and it may make proper pressure but it won't run right, the pump won't sound right either, it will be noisier. 2) I have first hand experience with this, If your EFI filter is not oriented to pass trapped air though it, it will cause big issues. Make sure the inlet is down and outlet is up.

[EagleMark]

He's changed from a inline pump from an old carb tank to a newer EFI in-tank pump now. Still same issue?

The EFI filters I use have an arrow, your saying backwards causes issues?

[RobertISaar]

if you run an EFI filter backwards, the filtering element can actually collapse and cause almost total fuel starvation.

[gregs78cam]

He's changed from a inline pump from an old carb tank to a newer EFI in-tank pump now. Still same issue?

The EFI filters I use have an arrow, your saying backwards causes issues?

The inline pump could have been sucking air from the inlet side somewhere....I've seen water pumps do that, It wouldn't leak out, but would pull air in through the seal, and act like a blown head gasket.....OR could have been picking up aerated fuel also, The intank pump like I said could be aerating the returned fuel. It all depends on the location of return and pickup.

With the filter, if it is oriented so that the inlet is on the top and outlet on the bottom it may never actually purge all the air out of it. Just some things to check.

[Mastiff]

Computer is trying to compensate for something?

I just mean this thing is in closed loop. It will compensate for fuel pressure, air leaks and other stuff within a pretty wide range to satisfy the O2. The plugs will only be rich or lean if the computer has hit the stops in its ability to make things right. At that point I'd expect an error flag.

[Mastiff]

This is sounding like a fuel supply issue. Almost like you enough for idle and maybe cruise, but when you ask for more, it's not there. That could be cuased by what you mentioned earlier about air in the fuel line. A couple of things that could cause this....1)If the return into the tank is aerating the fuel right around the pickup, the pump will pick it up and it may make proper pressure but it won't run right, the pump won't sound right either, it will be noisier. 2) I have first hand experience with this, If your EFI filter is not oriented to pass trapped air though it, it will cause big issues. Make sure the inlet is down and outlet is up.

This is VERY interesting. I was seeing air bubbles in my old setup and I could hear hissing if I put my ear to the lines. I blamed it on the in-line pump sucking air in somewhere, but I never found anything. Two things: the return line has not changed, AND my fuel filter is horizontal. It could be full of air. I take it that the factory arrangement is just the opposite, up and down. I'm going to go after this next. Kind of a bummer because I have the thing mounted so nicely in the exact same mount I had my pump in. Oh well.

[RobertISaar]

on all W-bodies, the filter is horizontal.... we never have those kinds of issues.

[gregs78cam]

Horizontal should be fine, And you do have a stock in-tank pump with the sock on the pickup right? That should stop it from picking up aerated fuel, possibly unless the return is pointed right at the pick up.

[Mastiff]

Horizontal should be fine, And you do have a stock in-tank pump with the sock on the pickup right? That should stop it from picking up aerated fuel, possibly unless the return is pointed right at the pick up.

Hmm, well that dashes my hopes on that one... I have the factory style EFI sender with the sock. It does look like the return line points right at the pickup...