TAGOES11S

iTrader: (13)

I have a problem I've been struggling with for a few months. When I start the car it smokes, runs extremely rich, sounds like its not hitting all cylinders, pops through the exhaust and has no power. It all goes away when it warms up. Usually after driving a mile or so. I assume the car is in open loop during this time. MTI programmed the car a few years ago and nothing has changed since. So far I have done the following.

only engine code I get is 1637 Alternator L-terminal

put in new plugs, and 02 sensors.

I'm struggling with this issue. Anyone have any suggestions on where to look or what to try? I do have autotap.

When in open loop what sensors is the pcm reading? I think thats where I should start..????

SSpdDmon

iTrader: (10)

The MAF is mainly responsible for fueling. However, the IAT, ECT, and MAP sensors can influence fueling some.

I'd try to find someone with a WBO2 and log a cold start with your scanner. Look for differences in commanded AFR and actual AFR, check where the spark is at, and check what the IAC is doing.

Chances are it's mechanical though if this just started happening all of the sudden.

ringram

MAP is important and IAT, ECT
Can you log it?

TAGOES11S

iTrader: (13)

Is there a way I can force it to stay in open loop why I check items out? I have another LS1 that I can actually swap MAF, MAP sensors, etc to try to find the problem.

Shallow Bay

iTrader: (3)

Do you have access to a tuning program? If not, you could disconnect one of the O2 sensors. This will force the car to stay in open loop. If you decide to go this route, make sure you remove the O2 sensor from the exhaust. Running exhaust over an unpowered sensor will most likely ruin it. This is all I could think of at the moment and I'm sure somebody has a better idea.

TAGOES11S

iTrader: (13)

I don't have easy access. I think the closest tuner is 2hrs away. Or is this something any shop with a good scanner could do a diagnostic on? I planned on taking the car in for a dyno tune, but didn't think they would want to spend the time trying to figure this problem out.

Doc

iTrader: (9)

The generator code is completely seperate from the OL fueling issue but needs to be addressed as well. In plain English, your alternator is not putting out enough juice for the total load of the vehicle's demand.

When the car is in OL you are not running off of your O2's and the tune needs to be calibrated.

NoGo

iTrader: (2)

A couple things you may want to try:

Clean the MAF see if that helps.

Put a scan tool on that thing and see what the LTerms are doing. If they are near +25% you may have vacuum leak that has creeped in.