Very Lean Idle and Cruise

[Ed Blown Vert]

Car has been sitting for a 6-8 months with the battery disconnected. It was running fine before.
But now I can't get it to idle. AFR on my wideband is around 18:1 when cold. Even though it is commanding about 10:1
If I override it, I can get the AFR to 14:1 and it idles fine. It evens cruises fine that way.
I have done the idle relearn. Checked for leaks, clean up the IAC. But I can't figure out why it is so lean.

[5FDP]

Can't help much without the tune and logs of it running.

Even at this point you may even want to replace the wideband sensor if you do not know how old it is, it could be pulling your leg.

[Ed Blown Vert]

Added the current tune to my first post. I'll have to get a log.

[cobaltssoverbooster]

a lot of widebands have a calibration process that is usually necessary every 6 months to prevent sensor drift.
anything that has sat for a year is considered unknown condition and should be replaced when trying to solve problems as hinted by 5FDP.

is there a reason you are commanding pe of 11.4 up until 4800 rpm then fattening it up until 7.5 by 6800 rpm? if you are running boost it would be wise to convert the OS to a 2 or 3 bar OS to utilize the Boost Enrichment Features.

[5FDP]

Sometimes it amazes me that somehow some vehicles run good with half the calibration not even done. Like if that file matches his sig then even more so lol. It's a 1 bar tune, running boost with zero VE tuning and a 1 bar MAP sensor. Shoot even the cylinder volume is stock for a 5.7 but it's really a 383 engine. So much potential power looks to left on the table.

[cobaltssoverbooster]

yeah i hear that. i wish i could dyno one of these rare cases and compare it to a complete file to see the gain spread.

[Ed Blown Vert]

Tune was done by a 3rd party many years ago. I have not touch the tune in a very long time.
Don't drive the car much. But it did run great before I parked it.
I'll look into replacing the WB.
Just not sure what could change the idle by having it parked for so long.

[Ben C]

What if the idle afr didn't change? And it's the afr sensor that changed? As has been suggested....

[Ed Blown Vert]

I am sure the AFR has changed. It won't idle unless I use the controls to add more fuel. Then it runs fine.

[ElecTech]

Verify your fuel pressure before you jack around too much.

[nskaats]

As suggested I would check fuel pressure.

After you get this figured out I'd strongly suggest you re-tune the car or have someone else do it. I see a lot of weird stuff going on there. The MAF curve is all over the place and the way they jacked up the PE in high RPM makes me think it was dropping fuel pressure on the dyno already.

[Ed Blown Vert]

Good idea on the fuel pressure. My FP gauge stopped working. Have to get it replaced.
I also run dual Racetronix pumps. I'll try switching to the other pump.

[nskaats]

If the secondary pump is on a Hobbs switch you could jumper the switch to kick on the secondary pump to see if that helps. Quickest and easiest test.

[Ed Blown Vert]

If the secondary pump is on a Hobbs switch you could jumper the switch to kick on the secondary pump to see if that helps. Quickest and easiest test.

I was going to switch them. But having them both on will also work. Thanks

[Ed Blown Vert]

Good call guys. It was fuel pressure. Each pump only showed 10lbs on a mechanical. And 30-35 lbs with both running.
Guess I will have to drop the tank.

[ElecTech]

Good call guys. It was fuel pressure. Each pump only showed 10lbs on a mechanical. And 30-35 lbs with both running.
Guess I will have to drop the tank.

I see it a lot with cars that sit often or are driven very little. If there are any rubber hoses in the tank, they will likely be shot and usually split when pressure gets re-applied. Even the "submersible spec" ones. Today's fuel gets very corrosive to rubber as it sits and ages. I try to only use Teflon or other plastics for in tank lines, if at all possible.

[stick8555]

also with this crapy gas flush the injectors just to make sure one is not clogged a bit seen that happen one sitting like that to

[Ed Blown Vert]

I see it a lot with cars that sit often or are driven very little. If there are any rubber hoses in the tank, they will likely be shot and usually split when pressure gets re-applied. Even the "submersible spec" ones. Today's fuel gets very corrosive to rubber as it sits and ages. I try to only use Teflon or other plastics for in tank lines, if at all possible.

I think he uses Nylon?