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1983 Lean Burn

Posted By: Redbaron314

1983 Lean Burn - 12/05/17 11:18 PM

I have a 1983 Chrysler Cordoba with a 318 lean burn 2bbl. I am not looking to delete it just yet so I am trying to troubleshoot and repair at the moment. So when I am trying to drive the car I have to barley press on the pedal or it falls flat on it nose and what sounds like pops through the carb. it has a Complete tune up recently done, timing verified with a timing light, new fuel filter and pump.
Posted By: Diplomat360

Re: 1983 Lean Burn - 12/06/17 12:18 AM

Man, that's a tough one...it's been years now since I've worked with the LB stuff, but with the car parked (shift selector in P or N) and timing light hooked up, what happens to the timing when you take it off idle???

The LB computer is programmed to control the timing once the carb comes off idle setting. I am thinking of this simple test as a way to at least determine if the LB computer is the problem, or maybe something else?

If the timing jumps (could advance, or it could retard) then the LB box is probably not the culprit, because the change in timing would indicate the LB ECU is reacting to the change...mind you, it could of course be reacting incorrectly...grrhh....
Posted By: Supercuda

Re: 1983 Lean Burn - 12/06/17 12:22 AM

Sounds like the accelerator pump in the carb is bad. I'd check that before I got all worked up about the LB.
Posted By: Redbaron314

Re: 1983 Lean Burn - 12/06/17 01:02 AM

Ok, thank you for the advice on my tricky situation. Now I have been hearing all over just buy the lean burn delete kit and so far before I remove all my hair that might be the best option. Problem being I cannot find this kit......
Posted By: Supercuda

Re: 1983 Lean Burn - 12/06/17 01:05 AM

There is no kit, per se.

You replace the carb with a non-lean burn one and put an electronic ignition conversion kit in

http://www.manciniracing.com/ma27331834033.html
Posted By: DarrenS

Re: 1983 Lean Burn - 12/06/17 01:15 AM

Originally Posted By Supercuda
Sounds like the accelerator pump in the carb is bad. I'd check that before I got all worked up about the LB.


I'd agree not to get worked up. Most problems I've had with lb cars have been attributable to the standard stuff (vacuum leaks and carb or ignition problems).

I would not just swap it all out unless you wanted to start upgrading everything for performance...
Posted By: RapidRobert

Re: 1983 Lean Burn - 12/06/17 01:30 AM

What Supercuda & Darren said, check the squirt for immediate tip in/quantity then if good I would search for a vac leak.
Posted By: Redbaron314

Re: 1983 Lean Burn - 12/06/17 01:54 AM

ok, and ty for the lb delete info also
Posted By: DynoDave

Re: 1983 Lean Burn - 12/10/17 06:24 PM

Certainly have to check the basics, like accelerator pump shot, before moving on.

I'm not as familiar with the later system...have worked on '77 and '78 models. But they used a ground wire on the throttle stop so the system knows when the throttle is closed. Also, they have a throttle position transducer (TPS in modern terms). If accelerator pump action seems good, checking the condition of these may help. The computer can't react if it doesn't know the throttle is moving.

If you have a set of '83 factory service manuals, they're sure to be of help. If you don't have a set, and get stuck, let me know. I have a set, and can check through the diagnostics for you, post some photos of those pages, etc.
Posted By: Diplomat360

Re: 1983 Lean Burn - 12/12/17 06:52 AM

Given the OP's comment below:

Originally Posted By Redbaron314
...it has a Complete tune up recently done, timing verified with a timing light, new fuel filter and pump...

...I honestly can not even imagine such a tune-up not covering something as basic as Carb 101: is the accel pump working? is it providing good enough volume of fuel? etc, etc.

But anyways...so my feedback is based on personal experience with different LB computers, specifically the timing differences programmed in on a 2 bbl vs 4 bbl setup.

In my case (many many years ago, so memory is a little faint) I picked up a 4 bbl setup at a swap meet. Given that I just installed my first 4 bbl carb (Carter TQ) I thought this would have been a great improvement. Well, something was probably wrong with that LB module because that very night I took the car out I had a massive backfire after a WOT run which literally blew off the muffler...LOL, yeah, impressed all my buddies, but gave me a busted exhaust pipe.

Sooo...off I went digging into the specs and all that, eventually found out that the 4 bbl unit did have a different timing amount (initial, off-throttle and vac-advance) that would have been the right move for my setup had it worked correctly. Who's to tell if I simply missed an additional input of some sorts though...I studied that darn hook-ups, but was just cutting my "teeth" on LB era Mopars at the same time.

Anyways, like I said, for what it's worth given my hands-on experience.
Posted By: rumblebee4232

Re: 1983 Lean Burn - 12/12/17 12:11 PM

Did the car sit for a while?? Is the fuel old?? I had one that acted like you are describing(not lean burn) and it turned out that there was water in the carburetor.. cleaned it out and it ran like new again..
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