gothchick

iTrader: (12)

It's either clogged injectors, or a leaky plenum. My .02 cents...

Snow-G

iTrader: (1)

I just ran into this problem yesterday...under idle or o load the car struggles with constant idle. It's weird, the temp in the morning was about 26 and the car ran fine. Later that afternoon the temp was around 40 and problems started. My normal idle will be 700, when things started happening I noticed it at 650 and wanting to stall. Usually when I turn the AC on the rpm will raise another 150 or so. This seemed to work until I could get home to check it out. Now at 850-900rpm, I come to a stop light and the car wants to die again! Havent had a chance to dig into it, but I will on Sat. I hope its just a leak.

So I took the upper and lower plenum apart and changed out the gasket. Everything looked good. Started her up, got to normal temp and same low idle and shortly after stall when in first gear. I think Ive got a bad injector or coil. I dunno.

goosegoose

iTrader: (8)

Here's an update.

On Monday night, I tried to tune out the problems by modifying the 0% columns in the UTEC. Nothing seemed to make any difference, in idle quality and low throttle performance, so I changed all the values back to the way they were before.

On Tuesday, i took the car to my mechanics to check for a plenum leak. We hooked up a smoke machine to the plenum, and pumped in the smoke to see if any of it seeped out in places where it wasn't supposed to. No leaks.

On Wednesday, we decided to check the throttle body. After taking a look at it, we were all surprised to see it was black and dirty as all hell. I have a feeling this is the motor oil residue from the time when my oil return line was leaking into the turbo months ago. Cleaned everything up. Started the car. It now idles very smoothly. The AFR numbers all seem to be more normal. I am no longer getting 21 AFR at part throttle. I'll have to see what happens today when i take it on the road to data log.

So that's the good news.
The bad news is that i now have an engine code lamp.

P0171
System Too Lean Bank 1

Any advice?

gothchick

iTrader: (12)

Glad the AFR / idle problem is fixed...
For the P0171 - Do you have hi flow cats, or test pipes?

goosegoose

iTrader: (8)

Nope. Stock headers, stock cats, stock y-pipe.

gothchick

iTrader: (12)

Hmmm, maybe try resetting the ecu? Maybe take it somewhere that has a sniffer to verify what the AFR is on bank 1?

I'm assuming your wideband is on bank 2?

goosegoose

iTrader: (8)

My Innovate Wideband is on the driver's side bank. Is that bank1 or bank 2?

gothchick

iTrader: (12)

Bank 1 = pass side
Bank 2 = driver side

goosegoose

iTrader: (8)

So according to the CEL code, i am running lean on the passenger side.
I'll plug some sniffers and scanners in to the vehicle today to see if I can tune it out.

gothchick

iTrader: (12)

Unfortunately, UTEC can't tune bank 1 & 2 independently. It tunes both banks the same way at the same time.

So if you're getting a code only on one bank, I'm guessing something tripped the sensor (plenum problem, leaker header, bad cat, etc), or maybe the sensor is bad. But to help narrow it down, I'd definitely verify what the AFR really is on that bank.

goosegoose

iTrader: (8)

Some more updates.

Last Friday, we did a full fuel injector cleaning, and cleared the codes.

By Saturday, the CHECK ENGINE LIGHT came back on.

On Monday, we plugged in a scanner to check the codes, and this time, there were two errors. Both banks 1 and bank 2 were being reported as too lean.

I think think this is progress?

Since then, I have had cleared the codes again, and raised all the 0% fuel values in my UTEC by +3. I have driven 40 miles on this so far, and there is no light yet.

Any thoughts?

athenG

iTrader: (2)

So is your A/F spot on again? I'll keep an eye on your A/F and see if things changes. You mentioned that your A/F has been dipping into the low 10's, I would lean that a little bit around 11.1 for extra safety. Your timing seem to be conservative enough (more conservative than mine) and I only get knock above 11.7 A/F.

Do you have an ODBII reader? I think you should always have one in your trunk. I have used mine so many times and it's well worth it.

Julian@MRC

iTrader: (28)

INJECTORS...

goosegoose

iTrader: (8)

Is it alot of work to change the injectors?

athenG

iTrader: (2)

not that hard, maybe 45 mins. But is your A/F still in lala land?

Injector Install is on Page 14 of the manual.

goosegoose

iTrader: (8)

My AFR is not spot on, but after about 400 miles, the check engine light has not come back.

In the end, it looked like the Throttle Body and Fuel Injector cleaning fixed the rough idle and cruising problems, and adding fuel through the UTEC fixed the check engine light problem.

I think I will need to have everything comprehensively re-tuned after winter.

athenG

iTrader: (2)

good luck on your journey I'm starting to collect some parts for spring. I just got some TP and I'm looking for a good Water/Meth kit and I'll have them installed and tune together with my FMIC I got from Gurgen.