Someone said that you can tell what factory tune you have by looking at the pulley. They said that the normal pulley is not a bolt on but starting at stage 2 it is bolt on. Does this mean i have stage 2?

 

Yes

 

It means you are at least stage 2. You have no idea of knowing what tune is on there unless you actually look at the tune file or have GM pull the ECU count and flash data from their database. That being said it can be tuned without notification of GM (HPtuners, Trifecta, EFI Live, etc etc etc)

 

That's not a GMS2 pulley fyi. That's a smoothflow pulley.

Better take it off and check the inside of the pulley for the size.

Also, take a look at your injectors.

 

^ yeah what color are the tops of your injectors?

 

looks just like my smoothflow 2.8 with a gms2 hub

 

My gmpp 42's have black tops, metal body.

Aftermarket 60's are usually skinny and all black & aftermarket 42's are usually all black as well, except for Bosch green giant 42's. They are all green.

Here are my GMPP 42's:

 

Thanks to all for the info. I just bought this car and have no idea about it's history. I can tell there is something not right with it. It had a bunch of diagnostic codes set which I think I have corrected but is still running rich and I say that because I have black soot spraying out the tailpipe when I rev the engine and can smell unburnt fuel. Also the car will start to idle rough and sometimes stall at red lights after it has been running for a while and is warmed up. Also I know this is a common problem but the car bucks and jerks terribly at times when lightly on and off the gas in all gears.

I will pull the pulley off this weekend and look for a size. As far as the injectors, I think they are all black. I can pull them and post a pic as well. Should the size or brand be embossed on them somewhere?

Let me ask another question. Once I figure out what kind of pulley and injectors, what route do you guys suggest I take? I have nothing against boosting the car's performance as long as it still runs ok, is reliable, and doesn't affect the fuel mpgs. Should I take it to a dealer and put everything back stock or have everything changed to factory stage 2, or try to find a local guy who tunes and see if he can straighten it out and get it running good?

Thanks again for all the help.

 

from your description, you probably have siemens 60s. they are a skinny black injector. when running them on a can tune, or have any small issues like a small exhaust leak, 60s don't idle well and perform poorly through light throttle transitions.

id say the absolute cheapest and best solution to have a comfortable driving car would be to get all the check engine light codes hashed out (looks like you already did) and then pick up used gms2 42s and a 3" pulley and get tuned for that. you can find the pulley and injectors for under 100. if not, let me know. ive got both lying around

if you don't mind the slightly rough nature of the 60s, im assuming that's what you've got, go ahead and get it tuned for them.

 

He is better off with a good tune for what he has though.

He needs to get a hold of a tuner or a HPT cable and I can hook that up.

 

Ok so here's an update. I think I fixed the rich condition, rough idle, and jerking problem by replacing a bad O2 sensor. Pics of old and new attached. This makes sense because the car would run fine until it warmed up and was driven a while which I attributed to the ecm not taking input from the O2 sensor until going from closed loop to open loop mode. Does this make sense? The fuel mileage is slowing going up on the computer too. Was as low as 13 mpg but now up to 18 and still rising. Also included pics of my injectors which i think look like the gmpp42s posted earlier. But I'm gonna leave it alone.because its running good now. The bucking was horrible when lightly on and off the gas in all gears. Thanks for everyone's input.

 

Yes those are gmpp 42's.