Hey guys im new to the forum first off and second i am new to dodge completely....ive owned nothing but fords but i couldnt pass up the deal i got on the car. Its an 87 diplomat with a 318 and a 2bbl, it has the lean burn setup, and its got 93000 miles (paid $150 for it). Anywho heres the deal. It starts up every time no problems, cold or hot doesnt matter. when i hit the gas under bout 10% it accelerates slow naturally but if i hit the gas anyharder it bogs down and dies dies if i hit it about wide open it burps, bucks a few times and shoots off like a rocket. It an intermittent problem but recently its been happening more and more. im new to dodge like i said so i have no clue where to even start. i know it needs a tune up but being a backyard mechanic it doesnt seem to be an issue with the cap rotor wires or plugs. I have messed with carbs before but never a feedback system. So any help would be greatly appreciated.

And admins im sorry if this is posted in the wrong section

 

It's most likely that lean burn computer on the side of the air cleaner. There are two possibilites that you can do. Try a Ready to run MSD distributer or switch to a older Mopar ECU unit.

 

My immediate solution would be to check with your state emission people and find out if your car falls under smog equipment inspection. This varies by state, and some states are ridiculous, going clear back to !!! 67 !!! when no car except CA cars had smog devices.

If your state does NOT require such, Google around re: removing "lean burn" and do some research, then come back here and ask. Some of the guys can help you convert the thing from lean burn.

Brem mentioned a different distributor. This is because for example, the lean burn distributors HAD NO advance mechanisms, which was done by the computer.

 

I live in Ohio and because the cars over 25 years old its not required and the county I live in doesn't require them as it is. If it is the computer is there a way to test it for aure without just replaceing it? And id rather not convert it but keep it stock because i really like the car and I want to show it by the end of summer

 

They sell reman lean burn computers at any auto parts store but I do not recommend them. Buy a Summit digital box and put it in the glove compartment. Then you have new but it still looks old under the hood. You will have to make sure you have a good magnetic pickup distributor and a good coil.

 

sorry guys i was on vacation so i havent gotten on here. is there a way to test and see if the computer i have is good or not? im used to actual ecu's and icm's mounted on the distributer ive never messed with a computer with a vaccuum port on it. i plugged the port on the compter and on the carb and the way it ran did not change i dont know if thats the only way to test it or not

 

Do yourself a favor and replace the distributor & ECU as suggested and don't look back ... IT is a legal modification. The factory did it back in the day because of the amount of problems they had..

 

i know its a legal modification and all that money is just tight after we got back from vacation so doing the conversion is a little out of the question at the moment. this is my only transportation untill i finish my f150. ive been driving it everyday and it seems like after i hit 25 i can go inbetween 10-90% throttle and its slow at accerating but it goes. and when i let off the gas slowly there are certain points where it launches forward, down shifts and rockets off....could this all be related to my choke thermostat being bad?

 

Look to see if the choke is opening all the way, if not that's probably part of the problem. The thermostat? I don't think that's causing your problem unless it's linked back the to the Lean Burn system. I recently changed my 77 Cordoba over to Pertronix distributor and coil. It was a very simple swap. All the LB stuff is gone and the car runs fine. Another simple change is to use the GM HEI system. If the Pertronix lets me down, I will most likely go that route. You can retro to a Chrysler high energy system fairly easy. In all cases you will have to replace the LB distributor and most likely the coil.

 

If money is tight go to the junk yard and for maybe $40-50 you can get a distributor and ECU and the wiring. YOU will spend more than the cost of the new kit to fix the lean burn system.

 

What cars had the ecu and dizzy that id need?

 

Any thing pre-77 I believe.

 

bump....does the lean burn system have a timing advance in the distributor or is it all electronic?

 

Some mechanical in the distributor but note the vacuum line on the lean burn computer. I am not 100% sure but I say that it adjusts the timing via vacuum increases.

 

Or version 3, but Eric seems to cringe @ the thought of non-Mopar goods to make em go.. ANd no there is no vacuum advance on the distributor @ all. If you do a search on Lean Burn Delete you may run into some usefull info

Think post is in Do-it-Yourself Section....

 

i wasnt sure because when im driving it i can floor it and it spits then goes but as im letting off the throttle at certain points it launches and rockets off i thought if there was an advance in the dizzy that may have been the problem but seeing as there is none. that cant be the problem. so the problem is all in the computer then i suppose.