Running Lean with Supercharger

[coreyemmons]

Hi all,

Finally hit my 15 posts! I looked around this forum pretty extensively, but I couldn't find the answer to this question. (If it is here I apologize) I have the supercharger, apparently installed at the dealer when the truck was new, but as a new owner of this thing I am constantly getting a CEL for running lean. I know that I can fix this by doing the 7th Injector system, which is expensive, but I am wondering if there are any other reasons that it might be throwing that code. I don't drive it hard (RPMs never above 3500-4000), and it doesn't seem like it isn't getting enough fuel. No pings, knocks, etc. Does anyone have any suggestions as to what else might cause the lean code?

I'm supposed to pass NJ inspection by tomorrow, so I'm hoping to get this corrected as soon as possible. I will buckle down and do the injector if I have to, but I would prefer to not spend the money right now.

 

[4Reak Show]

If installed properly it will NOT throw a lean code. The ECM has the ability to compensate under proper install and operation.

Guess is you have a leak somewhere. Throttle body gasket, base gasket or hose is the most likely. A shop can use a smoke machine to find even tiny leaks. When I installed mine years back there was one bolt that I missed final tightening that was like 3/4 turn loose and that was enough to flag a lean code.

All that checked, mass airflow would be next guess but again, check check and recheck the basics first.

Good luck

 

[coreyemmons]

If installed properly it will NOT throw a lean code. The ECM has the ability to compensate under proper install and operation.

Guess is you have a leak somewhere. Throttle body gasket, base gasket or hose is the most likely. A shop can use a smoke machine to find even tiny leaks. When I installed mine years back there was one bolt that I missed final tightening that was like 3/4 turn loose and that was enough to flag a lean code.

All that checked, mass airflow would be next guess but again, check check and recheck the basics first.

Good luck

Thanks so much! I'll have those checked.

 

[LiquidFlame]

I just went through the same thing... Mine was a lean bank 1 code after I rebuilt my SC. Ended up being a vacuum leak on the supercharger itself, on the flange itself where it meets the throttle body. Mine is a 2nd gen SC and on my 2002, that barb just needs to be plugged. It goes to the vacuum throttle opener on earlier 3rd gen years.
Also, clean your MAF sensor as a good measure, seems to cause a lot of lean issues. Even if thats not the problem, its easy to do and a good habit to get into.
Best of luck!

 

[coreyemmons]

I just went through the same thing... Mine was a lean bank 1 code after I rebuilt my SC. Ended up being a vacuum leak on the supercharger itself, on the flange itself where it meets the throttle body. Mine is a 2nd gen SC and on my 2002, that barb just needs to be plugged. It goes to the vacuum throttle opener on earlier 3rd gen years.
Also, clean your MAF sensor as a good measure, seems to cause a lot of lean issues. Even if thats not the problem, its easy to do and a good habit to get into.
Best of luck!

Good to know. I'll take a look at that in the morning, maybe it's something that simple.

 

[coreyemmons]

If installed properly it will NOT throw a lean code. The ECM has the ability to compensate under proper install and operation.

Guess is you have a leak somewhere. Throttle body gasket, base gasket or hose is the most likely. A shop can use a smoke machine to find even tiny leaks. When I installed mine years back there was one bolt that I missed final tightening that was like 3/4 turn loose and that was enough to flag a lean code.

All that checked, mass airflow would be next guess but again, check check and recheck the basics first.

Good luck

I just went through the same thing... Mine was a lean bank 1 code after I rebuilt my SC. Ended up being a vacuum leak on the supercharger itself, on the flange itself where it meets the throttle body. Mine is a 2nd gen SC and on my 2002, that barb just needs to be plugged. It goes to the vacuum throttle opener on earlier 3rd gen years.
Also, clean your MAF sensor as a good measure, seems to cause a lot of lean issues. Even if thats not the problem, its easy to do and a good habit to get into.
Best of luck!

Found it! The hose going from the PCV to the supercharger had a nice big crack in it because it was too small and didn't have a clamp like it was supposed to. Fixed that, cleaned the MAF and throttle body for good measure, cleared the code, drove 50 miles, and passed inspection. Woohoo!

 

[4Reak Show]

Glad to hear it. The simplest fixes are always the best. Keep on keepin on

 

[LiquidFlame]

Good to hear! Like 4Reak said, its sometimes the little things that cause the problems.