LTFT -23. CEL set for B1 rich. Places to start?

[Alec Kerchner]

Hi all,

 

Started the truck up tonight and it immediately set a MIL for B1 rich. I run a converted L83 for E85. That however has been fine for 3 months. Its about 10% heavier on bank 1 than bank 2. Is it possible for an injector to be leaking?

[Supreme Pizza]

Its a very old school way of doing things, but but my 86 year old mechanic friend would say to pull the plugs. I have heard him say it 100 times while we were working on customer vehicles. Pull the plugs, what do they look like? That will tell you how each cylinder is firing. If one injector is leaking, you will be able to tell just by the plug insulator appearance.

[CamGTP]

Could be a o2 sensor as well. Swapping sensors side to side would be an easy test too.

[Supreme Pizza]

27 minutes ago, CamGTP said:

Could be a o2 sensor as well. Swapping sensors side to side would be an easy test too.

 

 

Ya, pats swapping works pretty good. Swap stuff around and see if the code follows the parts.

[Alec Kerchner]

11 hours ago, CamGTP said:

Could be a o2 sensor as well. Swapping sensors side to side would be an easy test too.

Good thought. I'll give this a shot. Do you think -10 on the other bank is too high? 

[M1ck3y]

7 hours ago, Alec Kerchner said:

Good thought. I'll give this a shot. Do you think -10 on the other bank is too high? 

 

Yes. They should be the same but yours is way out. I would check for leaks at the intake manifold or the exhaust. 

 

My truck picked up a small leak after a kooks header swap. One of the flanges wasn't flat. Torquing it down straightened it out for the most part, but not enough to be perfect.

Edited December 22, 2021 by M1ck3y

[movario]

18 hours ago, Supreme Pizza said:

Its a very old school way of doing things, but but my 86 year old mechanic friend would say to pull the plugs. I have heard him say it 100 times while we were working on customer vehicles. Pull the plugs, what do they look like? That will tell you how each cylinder is firing. If one injector is leaking, you will be able to tell just by the plug insulator appearance.

 But nowadays you can only use this method to compare cylinders on one bank with eachother. Reading a spark plug is difficult nowadays because of constantly lean running engines.

 

@OP, are your exhaust fumes smelling like (unburnt) fuel? How is your engine generally running? Is the idle smooth?