Lean in both banks plus multiple misfires

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

tommypvt

I'm Awesome
Joined
Jan 3, 2015
Messages
114
Reaction score
86
Location
BTV
Trying to track down the cause of my issues could use a little help.

Getting a lean code in both banks. Plus a multiple misfire code. 99 yukon. I bought over the summer for $500. The previous owner fancied it a racecar so it has a kn style intake/filter.

I have replaced the plugs fuel pump/filter, ac delco cap, rotor and wires still getting the codes.

Not sure where to go next neighbor has a parts tahoe of the same year so may pull the intake off it and go back to stock.

Would this be a distributor issue? Should I replace it with the cardone on amazon that is metal?

Any other ideas? I need to check for vacuum leaks but there really isnt much hose on this thing.

Thanks
 

slowburb

all motor
Joined
Mar 26, 2011
Messages
1,632
Reaction score
676
Location
Louisiana
Definitely could be a vacuum leak. Lean is too much air or not enough fuel. What's the fuel pressure read at key on/engine off, how quickly does it bleed off? Fuel pressure at idle?
 

magimerlin

I'm Awesome
Joined
May 27, 2013
Messages
2,451
Reaction score
650
Location
Raymond, NH
What are the codes your seeing. The actual code number.. P???

sent from what use to be a great country...
 

magimerlin

I'm Awesome
Joined
May 27, 2013
Messages
2,451
Reaction score
650
Location
Raymond, NH
Ok. I might go to my shop today to reinstall my headliner. If I do I'll look them up on our system and see what it says there...

sent from what use to be a great country...
 

tommypvt

I'm Awesome
Joined
Jan 3, 2015
Messages
114
Reaction score
86
Location
BTV
Tha
Ok. I might go to my shop today to reinstall my headliner. If I do I'll look them up on our system and see what it says there...

sent from what use to be a great country...
thanks
 

tommypvt

I'm Awesome
Joined
Jan 3, 2015
Messages
114
Reaction score
86
Location
BTV
Stuck poppet injectors sounds like a likely culprit.

Just ordered a new updated spider I should get it tuesday. Hopefully that will help. I still need to check the vac lines and put a stock intake on it to see if that will help.
 

Nathaniel2g

Rusty Islander
Joined
Oct 4, 2015
Messages
370
Reaction score
82
Location
Prince Edward Island, Canada
Just ordered a new updated spider I should get it tuesday. Hopefully that will help. I still need to check the vac lines and put a stock intake on it to see if that will help.

Intake has nothing to do with it. Only thing that would cause a lean is not enough fuel or too much air, in my opinion. Check your MAF.
 

tommypvt

I'm Awesome
Joined
Jan 3, 2015
Messages
114
Reaction score
86
Location
BTV
Intake has nothing to do with it. Only thing that would cause a lean is not enough fuel or too much air, in my opinion. Check your MAF.

My thoughts on the intake are that it is getting unmetered air after the maf. Its all pipe and silicone connectors. I sealed it up tight but you're right it probably isnt the issue. I'll swap the maf tomorrow to check it.
 
Top