Hello folks - another M-Body fan joining here! Look forward to learning from y'all!

[ffaruqi]

Good day to all here, I own a 1987 Fifth Avenue that I cherish. It has about 40k miles. I am trying to keep it as original as I can, but do admit the Lean Burn (LB) system may be something I opt to remove. I am sure many of us have done this on the site (always happy to hear how feel about that change for those who have removed the LB). Thank you!

 

[Aspen500]

Nice 5th! Lots of m-body guys and gals on here with info.

 

[Camtron]

Nice ride!
Other people will tell you that the lean burn itself rarely goes bad but, any of the things it gathers its information from could be bad/going bad and then you’re left with a crap shoot of replacing parts until you change the right part (since there’s no way to communicate with the lean burn for diagnosis) and it finally starts drives right again.
Personally, I’m a fan of taking the time to remove it and clean up the wiring. Heck, if a fella really wanted to, you could delete it but, still keep it under the hood for a stock appearance when the hoods up.

 

[Hayzoos]

Other people will tell you that the lean burn itself rarely goes bad but, any of the things it gathers its information from could be bad/going bad and then you’re left with a crap shoot of replacing parts until you change the right part (since there’s no way to communicate with the lean burn for diagnosis) and it finally starts drives right again.
Personally, I’m a fan of taking the time to remove it and clean up the wiring. Heck, if a fella really wanted to, you could delete it but, still keep it under the hood for a stock appearance when the hoods up.

Back in the mid '90's I had my first 5th Ave. It had "drivability issues" so I set about as you said changing parts starting with the lower cost and trying everything to avoid replacing the LB computer. I finally gave in and changed it and it ran like a top. I was pleasantly surprised that the cost of the LB was less than $80, but I probably spent that much or more on other parts.

On the current one I have transplanted a '78 'vette high-energy ignition (Chevette that is) and that did not cure the issues. So I would say the lean burn is not malfunctioning. I plan to keep the LB computer in place when I do eventually switch. I have a Carter BBD knockoff for replacing the Holley feedback carb. I think my problem is in the hard to get to fuel/vapor lines on the right subframe rail that did not get replaced yet.

@ffaruqi That is a nice one there. I do not want to venture too far from stock myself. I have changed out marker and turn signal bulbs for LED and the radio for a mechless USB/Bluetooth unit.

 

[LSM360]

Welcome! Nice Fifth Ave. My feelings on the LB removal are don't replace it until you have to. If it's working keep it. When it is working it works well. My second piece of advise is that if you decide to replace it I'd probably avoid using orange box ecu. They are kind of hit and miss for reliability.