many have had that issue.
Lean at wot
- Thread starter TireFryer
- Start date
I'm not so sure I can say that.
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.
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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
The New Kid
- Joined
- Dec 21, 2001
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
TurboTweak Guy
- Joined
- May 25, 2001
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
TireFryer
The New Kid
- Joined
- Dec 21, 2001
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
TurboTweak Guy
- Joined
- May 25, 2001
Almost sounds more like a MAF problem, but lets see what the log looks like.
TireFryer
The New Kid
- Joined
- Dec 21, 2001
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
I forgot about what the O2 sensor looks like when you have open loop idle
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.
Yes,try that.
Eric Stage I
TurboTweak Guy
- Joined
- May 25, 2001
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.
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.
Hook the O2 back up.
I just looked at one of my old logs and it shows right around 100 grams at a similar pressure and rpm.
