Diagnosis ? Lean Burn Computer Dying or another problem?

[lowbudget]

I'd find a Carter BBD or a Holley 2280 with a vacuum port (non elec. feedback) and do the lean burn delete and go from there http://www.forfmjbodiesonly.com/classicmopar/showthread.php?2995-Lean-Burn-Conversion-101&highlight=lean+burn I'm fixing to do mine days off. I had the lean burn strand me once in my old 85 Fifth Ave, and the dual pick up strand me in my 86 W250. My thought on the deal is to eliminate the problem before it becomes one as with my luck it is usually in the middle of nowhere.
I picked up a NOS BBD for 30.00 off e-bay last days on and a NOS rebuilt 2280 for 25.00 the hitch before that off of FABO. I got the new gas proof rebuild kits and will be going though which ever one I decide to use. I have the Mopar ignition kit so I'm set. A guy can scrounge the parts if needed just beware the BBD's usually are worn at the throttle shaft and need bushed and the distributor is probably pretty worn also. The wiring harness to go this route can be had from junkyard, Summit or Mancini. If it was me that's where I'd start. JMO

 

[Bruce85FifthAve]

Update - Since last October: I replaced the EGR valve and the water pump. The car ran good with the exception of the coolant leak re-appearing near the back of the motor, on the Right -passenger side. The car continued to run good until 2/14/2015 when it started running very rough and died. Now it will barely start and runs rough - like it is not firing on at least two cylinders with white exhaust smoke coming out that smells like starting fluid before it dies; so I can't drive it anywhere. I pulled the last two spark plugs on the right side of the motor and they were "sooty" but not oil soaked or wet. So I'm back to trying to figure out what is wrong! I wonder if the catalytic converter could be plugged? What are the symptoms of a bad catalytic converter?? Any ideas, I sure would appreciate!

Thanks again,
Bruce

 

[Master M]

Hello, I would replace the magnetic pick up(s) in the distributor. My 1988 only has 1. Is the carb flooding ? When my car is part way warmed up and then turned off and it sits for a little while, it runs rich on start up and will not want to restart if it is allowed to die. I believe my carb is being enriched by the computer, sensing the engine is cooled down some therefore needing more fuel. The next thing I would try is the computer. Click the link. I also copied one of the articles for you below. Let us know your progress. http://www.allpar.com/mopar/lean-burn.html

After I bought my 1980 Newport, I added a set of Borg-Warner KoolWire II wires, (magnetic suppression, lower resistance). The car ran as expected for a 360 with a 318-size Carter BBD on it (the only year like that). As I got the carb idle system issues taken care of, it developed an intermittent “skip.”
If I was sitting in a drive-thru at idle in gear, if the idle suddenly got a little rougher, but not much; as soon as I throttled into it to move, it'd start running very rough. One day, while idling, I noticed the idle get a little rougher. Just a little more quiver. But as soon as I eased forward, it really acted flaky. More throttle made it worse. The word “gutless” would have been too nice for the way it was running. I'd manually upshift it from 1-2 so that the rpm in 2 would not be too low.
I got it up to about 50 on the flat, in 2, but any small incline might have just as well be a full blown mountain. It was a struggle with massive amounts of throttle just to try to maintain 40mph on the overpasses. But I got it safely in the shop and then shut it off. I tried the restart and it immediately started and ran as if nothing was wrong . . . or had ever been wrong. Then it all fell in to place. Killing it and then restarting had reset the computer. I could have done that before coming to the shop!
In that short drive of about 15 miles, it managed to use about 1/2 tank of gas!
I looked in my service manuals for possibilities of what the problem might be. My Chrysler contacts recommended I check all of the wiring harness grounds, which I did, scraping paint and such for a better contact . . . no change.
I checked the spark plugs

, for general principles. When I pulled the #1 spark plug boot off, the terminal stayed on the spark plug, yet the boot and wire were in my hand. It looked as if it hadn't been fully crimped from day one. I got some silicone spray and pushed more of the wire through the boot and reterminated the wire with the old terminal. Put everything back together and put it back on the spark plug. Nothing wrong with the way the plugs looked. I checked a few others and determined them to be good. Reterminating that wire solved the problem. I guess that as the engine shook a little at idle, sometimes if it shook just right, the connection would arc and send a back-feed to the distributor and computer and it'd go into Limp In mode.
I used to get amused at the many mechanics who would hold up the Lean Burn system as a "Gotta take it back to the dealer" complaint . . . until I found a Chilton book that told how to troubleshoot the system using a volt-ohm meter. The whole thing, like modern computer systems, is based on voltage change and resistance values. It's a more labor intensive process than simply hooking the Chrysler box to it, but it works anyway.
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[Jack Meoff]

Bruce,
Internet diagnosis is always a difficult thing but here's my two cents.

People almost immediately point to the computer as ngine but in my experience the computer either works or it doesn't....there's no real middle ground. The fact that this problem sounds like it started almost immediately makes me think it's something else.

Because to me it sounds like some kind of timing issue I'm thinking one possibility is a cracked distributor cap or broken or worn out rotor. Could also be a bad wire or wires. When is the last time you did a full tune up on it? Another possibility is the distributor drive gear has called it a day and has jumped your timing. Throwing a timing gun on it would tell you. There's also the possibility that the nylon drive gear on the distributor has given up and has thrown the timing out. Again a gun would tell you what's going on there.
Could be a lot of things and it's hard to tell without being there. If it hasn't seen new plugs, wires, cap and rotor for a while I'd start there. As mentioned it could be the run pickup in your distributor too. Could also be a vacuum leak somewhere. Could also be the carb or choke in particular. Have you popped the air cleaner cover to make sure the choke is opened all the way when it's warmed up?.....lots of possibilities unfortunately.

The white smoke is a concern....that usually means coolant.
How's the oil look? Any water getting in there?
If your oil is the least bit creamy you need to address that immediately.

Any extra details you can provide would help.

 

[Monkeyed]

Update - Since last October: I replaced the EGR valve and the water pump. The car ran good with the exception of the coolant leak re-appearing near the back of the motor, on the Right -passenger side. The car continued to run good until 2/14/2015 when it started running very rough and died. Now it will barely start and runs rough - like it is not firing on at least two cylinders with white exhaust smoke coming out that smells like starting fluid before it dies; so I can't drive it anywhere. I pulled the last two spark plugs on the right side of the motor and they were "sooty" but not oil soaked or wet. So I'm back to trying to figure out what is wrong! I wonder if the catalytic converter could be plugged? What are the symptoms of a bad catalytic converter?? Any ideas, I sure would appreciate!

Thanks again,
Bruce

Might want to check the compression while you're at it. You could be dumping coolant in through a blown head gasket, which would cause white smoke, and not really wanting to start. You said it smells like starting fluid? Could be unburned fuel mixing with the coolant steam? Good luck

 

[Bruce85FifthAve]

Thank you Master M, Captain Caravelle, and Monkeyed for the ideas and suggestions. I will check all those things and buy a compression gauge and maybe a leak-down tester. I am concerned about the over rich condition that the spark plugs indicated that might lend itself to plug the catalytic converter, it also seems to stumble more with more throttle. When it rains it pours as this is but one of three cars in my family that have all failed at once!!! I'm a bit slow tending to things since I am working two jobs. I will let you know further developments as they occur. Thanks again, for giving me direction.
Bruce