Lean at wot

[Mr.Spool]

The fuel pressure even with the line off i cant get below 42 psi so i do believe I am one of the unlucky few that needs a return line made... I have -6 hose that I'll be having made on monday and running a new return line. The pressure stays right around 42-43 line on or off, It lowers maybe 1 psi but that's it.

many have had that issue.

 

[Ttype6]

lol i dont have a problem

I'm not so sure I can say that.

 

[Ttype6]

The pressure stays right around 42-43 line on or off,

Ok,so you should be rich. Disconnect the orange computer feed wire at the battery to erase what the computer has learned. Disconnect the factory O2 sensor,reset all of your chip parameters to what they were before and take the car for a drive and see how your wide band reacts.

 

[TireFryer]

So you're saying to reset the whole ecm, unplug the narrowband, and let the car drive completely off of the wideband?

 

[Ttype6]

So you're saying to reset the whole ecm, unplug the narrowband, and let the car drive completely off of the wideband?

The engine will run in open loop and will receive fuel based on the program in the chip. Because the computer will not receive info from the O2 sensor,it will not refine the air fuel ratios so it might run a little rich or lean. We just want to see if it runs better. If it does,we can suspect the O2 sensor. The wideband will show us what the air/fuel ratios are so you'll want to record some data.

 

[TireFryer]

Just started the car without the narrow band plugged in, She's fat now... ran right around the 10.8:1 setting for about 3 minutes. So is this a bad narrowband? FP was 38-39 line on (removed a schrader valve from the adapter i have the gauge running on and that seemed to fix it) It was idling quite high, around 1800-2000 rpm

 

[Ttype6]

Just started the car without the narrow band plugged in, She's fat now... ran right around the 10.8:1 setting for about 3 minutes. So is this a bad narrowband? FP was 38-39 line on (removed a schrader valve from the adapter i have the gauge running on and that seemed to fix it) It was idling quite high, around 1800-2000 rpm

Take it for a drive

 

[Eric Stage I]

I am one of the unlucky few that needs a return line made...

No, you're the unlucky majority, so don't feel bad. I've never seen one that didn't need return line mods with that pump.(bone stock return line on Buicks, not the TTA, as it flows better) Many people run it that way anyway, and let the BLM's drop to compensate.

That log you posted was never in boost, so I don't see a problem in the log. It's not uncommon to see lean spikes when first blipping the throttle. Need a log getting up into boost to see what's happening.

On the return line thing, many people try to get the pressure down by backing out the regulator screw all the way. This can make the pressure not rise properly with boost. You really need some preload on it, so you're better off increasing pressure say 5psi over your min.

Sounds like you're working on the return line, so fix that up and go from there.

Eric

 

[Ttype6]

In your opening comments you said the engine didn't spit and sputter under normal driving. Did it spit and sputter when you increased the throttle opening? Did you drive it and record another log?

 

[TireFryer]

I did drive it, i forgot to log so ill go take one... It idles at 10.8 ish but as soon as i give it gas to start going, starts to build some pressure, the boost gauge was at -2 and the car wouldn't accelerate because it was at 19:1 so its definitely a fuel problem. I'll go take a log real quick

 

[Eric Stage I]

Almost sounds more like a MAF problem, but lets see what the log looks like.

 

[TireFryer]

Here's a run... it gets scary lean... I do think i might not have any preload on the regulator like eric said, trying to get the fuel pressure down. I'm having a return line made on monday so ill probably get another run in with the new return line sometime next weekend

 

[Ttype6]

I forgot about what the O2 sensor looks like when you have open loop idle

Here's a run... it gets scary lean... I do think i might not have any preload on the regulator like eric said, trying to get the fuel pressure down. I'm having a return line made on monday so ill probably get another run in with the new return line sometime next weekend

Hook the O2 Back up and reset the computer and turn the Fuel pressure up to 46 line off. Then record a log during your first start after the reset so it will run in closed loop idle. Give it some time to relearn before logging.

 

[TireFryer]

So reset the ecm, 46 psi line off, log during first start and drive to relearn, and get up into boost?

 

[Ttype6]

So reset the ecm, 46 psi line off, log during first start and drive to relearn, and get up into boost?

Yes,try that.

 

[Eric Stage I]

In that log, at about 0-1 psi boost, you have MAF airflow around 50 gr/sec, normally I would see around 75-100 grams/sec at that manifold pressure. It appears like this might be a MAF issue, or there is a big air leak after the MAF somewhere (like a hose blown off).
Also, I noticed your stock O2 reading is dead (stuck at .400), but that won't necessarily cause this lean issue. Could cause your rich idle though.

 

[TireFryer]

I actually had the stock o2 unplugged like Ttype6 recommended. Ill check for any air leaks and i do have another ls1 maf without a screen that I can try and swap.

 

[Ttype6]

So reset the ecm, 46 psi line off, log during first start and drive to relearn, and get up into boost?

Hook the O2 back up.

 

[Ttype6]

In that log, at about 0-1 psi boost, you have MAF airflow around 50 gr/sec, normally I would see around 75-100 grams/sec at that manifold pressure. I

I just looked at one of my old logs and it shows right around 100 grams at a similar pressure and rpm.

 

[TireFryer]

So should i also switch my maf? i have one... there arent any leaks or holes and the translator is set how the manual says for the tt chip on on on off and both dials at 0