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Discussion Starter #1
Have two vans...86 and 87...with the horrible Mikuni carb. Am switching out the terrible 2.6 engine for a 2.2, but I have been told that some people who have these carbs on their vehicles have found a way to make these terrible excuses for a carb run pretty good, with no loss of power or economy.

If there is anyone out there who has one of these engines and knows how to make these carbs run good (without the 3K idle at startup), please contact me. The car is very nice and runs well (when it runs).

Thanks very much!

'slim slow slider'
 
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I rebuilt my carb, and shaved the shield off the top left of the carb. There's two adjustment screws that take a ton of playing and homing. Its very important that these carbs are free of debris and can easily move. Ensure that the vacuum discs are in good operating order. Most of my issues on rough idle have come from the EGR. But a rebuild kit from Autozone and a good cleaning helped me out hugely. I'll take some pics later to better illustate it. Where did you find one of those? We've been looking for a 2.6 after my cousins 2.6 Caravan was run into by a Dodge Ram. That was 2006. We're still looking.
 

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You can grind a slot into the shield rivets and unscrew them with a screwdriver. You will want guidance from a service manual with good pictures and procedures on the Mikuni carburetor. It is very intricate with lots of little parts.
The choke is coolant-heated with a gear rack that slowly opens the choke and ramps down the idle speed as it warms. As stated, their biggest issue was the mechanism sticking and binding on a fast, rich idle.
The gear rack has a dot on it that has to be timed to the choke plate plastic pinion gear.
A carb 'Jiffy kit' would be nice for fresh parts and the detailed instruction/adjustment sheet.
These carbs were scary to work on at first because they were so complex and unconventional, but were quite serviceable and did run very nicely when everything worked as it should.
 

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Discussion Starter #4
codypet said:
I rebuilt my carb, and shaved the shield off the top left of the carb. There's two adjustment screws that take a ton of playing and homing. Its very important that these carbs are free of debris and can easily move. Ensure that the vacuum discs are in good operating order. Most of my issues on rough idle have come from the EGR. But a rebuild kit from Autozone and a good cleaning helped me out hugely. I'll take some pics later to better illustate it. Where did you find one of those? We've been looking for a 2.6 after my cousins 2.6 Caravan was run into by a Dodge Ram. That was 2006. We're still looking.
Hi, trying to find a way to get these carbs to stop revving at such a high speed at idle. I know about the water choke. I had seen an article from a guy that managed to install a manual choke to control the idle at startup. However, the article has vanished from the web. By the way, there are rebuilders out there who will not fool around with these carbs because they are so troublesome. Rebuilt ones off the shelf are very expensive, as you probably know. Not sure of what you mean bu '...adjustment screws that take a ton of playing and homing?????....' Please explain. Thanks very much!!
 

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When I had my 2.6 mini-van, I had an issue with occasional high idle and engine run-on (would keep dieseling after the ignition key was out). I ultimately traced the problem to a bad AC kick-up relay. The relay is mounted near the left headlight but over just a bit toward the center of the vehicle. I found one in a junk yard off a 96 RAM Van with a 2.6.
 

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My grandma had two 86' with the 2.6 I can't remember any drivability issues, but what sent them to early grave was inability to pass CA smog inspection. Otherwise she would still have one of them.

The last she one had was the ultra rare 8 passenger! I don't think I have ever seen another since.

Overall they where good vans, ran well and since she was in town mostly the 2.6 was very nice, good power for stop n go. However the highway performance left something to be desired.

I just remembered, a buddy of mine said he was offered to buy a 85 Dodge Raider with 2.6 ran good, only $500! The kicker seller could not get it to pass smog.
 

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Discussion Starter #7
John Wood said:
When I had my 2.6 mini-van, I had an issue with occasional high idle and engine run-on (would keep dieseling after the ignition key was out). I ultimately traced the problem to a bad AC kick-up relay. The relay is mounted near the left headlight but over just a bit toward the center of the vehicle. I found one in a junk yard off a 96 RAM Van with a 2.6.
Thanks! Might as well replace it and see what happens!
Jaime said:
My grandma had two 86' with the 2.6 I can't remember any drivability issues, but what sent them to early grave was inability to pass CA smog inspection. Otherwise she would still have one of them.

The last she one had was the ultra rare 8 passenger! I don't think I have ever seen another since.

Overall they where good vans, ran well and since she was in town mostly the 2.6 was very nice, good power for stop n go. However the way performance left something to be desired.

I just remembered, a buddy of mine said he was offered to buy a 85 Dodge Raider with 2.6 ran good, only $500! The kicker seller could not get it to pass smog.
They are troublesome engines with that darned Mikuni carb. Then again, there are people who have them and don't have any problems with them! Go Figure!!!
 

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Most problems I had with my '86 were with the awful cat Crankcase/converter pulse valve, it kept failing until I finally changed brands.

Another issue was clogging of the choke water hose once.

However, the biggie on my '84 was a broken camshaft. Never had that happen on any vehicle before!

My '86 is down now with a failed brake cyl, too lazy to replace it!
 

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Discussion Starter #9
slim slow slider said:
Hi, trying to find a way to get these carbs to stop revving at such a high speed at idle. I know about the water choke. I had seen an article from a guy that managed to install a manual choke to control the idle at startup. However, the article has vanished from the web. By the way, there are rebuilders out there who will not fool around with these carbs because they are so troublesome. Rebuilt ones off the shelf are very expensive, as you probably know. Not sure of what you mean bu '...adjustment screws that take a ton of playing and homing?????....' Please explain. Thanks very much!!
I'll look your pictures soon. I wish I knew someone who could rebuild one of the carbs I have!! I'd even ship it out of State IF I could locate someone who could rebuild mine. Have the kit.
 

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ImperialCrown said:
You can grind a slot into the shield rivets and unscrew them with a screwdriver. You will want guidance from a service manual with good pictures and procedures on the Mikuni carburetor. It is very intricate with lots of little parts.
The choke is coolant-heated with a gear rack that slowly opens the choke and ramps down the idle speed as it warms. As stated, their biggest issue was the mechanism sticking and binding on a fast, rich idle.

A carb 'Jiffy kit' would be nice for fresh parts and the detailed instruction/adjustment sheet.
These carbs were scary to work on at first because they were so complex and unconventional, but were quite serviceable and did run very nicely when everything worked as it should.
This! I'll get some pics later, but I managed to get this thing to run like a top. There's a screw on the front of the carb by the bottom that faces the grille, 1/4 turn in either direction and you can raise and lower the idle at will.
 

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slim slow slider said:
I'll look your pictures soon. I wish I knew someone who could rebuild one of the carbs I have!! I'd even ship it out of State IF I could locate someone who could rebuild mine. Have the kit.
I bought a reman Mikuni 2.6 carb from these guys several years ago and it worked fine. The prices are reasonable but you do pay for shipping and core return. They test every carb before it leaves their shop.
http://www.nationalcarburetors.com/cat-chrydodgemitsutruck.html
 

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Discussion Starter #12
John Wood said:
I bought a reman Mikuni 2.6 carb from these guys several years ago and it worked fine. The prices are reasonable but you do pay for shipping and core return. They test every carb before it leaves their shop.
http://www.nationalcarburetors.com/cat-chrydodgemitsutruck.html
Good to know. Thanks very much!!
codypet said:
This! I'll get some pics later, but I managed to get this thing to run like a top. There's a screw on the front of the carb by the bottom that faces the grille, 1/4 turn in either direction and you can raise and lower the idle at will.
OK, I'll examine my carbs and determine if I can find that screw.One of my vans in CA emissions, the other is Federal. The carbs are different.
 

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So here is the carb. The adjustment screw is the one facing the camera directly on the right 1/3 of the carb directly below the carb. IIRC turn to the right was up, turn to the left was down. I had the whole thing apart and did a rebuild myself when it was running rich and would shut off on its own. I bought the service manual for this car and its proved very very valuable in the years I had the car. They're on ebay for like $20. A closer shot.
 

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Discussion Starter #14
codypet said:
So here is the carb. The adjustment screw is the one facing the camera directly on the right 1/3 of the carb directly below the carb. IIRC turn to the right was up, turn to the left was down. I had the whole thing apart and did a rebuild myself when it was running rich and would shut off on its own. I bought the service manual for this car and its proved very very valuable in the years I had the car. They're on ebay for like $20. A closer shot.
Yes, I found that screw. I'll attempt to turn it down and see what happens. But it's my understanding that the high idle is governed by the condition of that water choke. Once the water running thru the choke heats up, it drops the idle down. I have been told that screw in the photo is to set the idle, after it warms up. BUT... at this point, I will try anything to try and get this carb to run right. More after I make the adjustments. Thanks very much for the pictures!
 

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I believe you are right. That screw is for warm idle. IIRC there is also a screw that controls the fast idle (i.e. choke partially closed).

If you have a slow opening choke, there is a possibility that the water housing is covered in a lime (like) buildup, which acts like insulation to the thermal control sensor. I found that filling the water housing in the carb with straight radiator flush and letting it sit for 15 minutes or so helped desolve some of that buildup and helped speed the choke opening time or got it closer to the original opening time when the vehicle was new. Of course, flush out the radiator cleaner after 15 minutes since it is a minor acid type cleaner.
 

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Discussion Starter #16
John Wood said:
I believe you are right. That screw is for warm idle. IIRC there is also a screw that controls the fast idle (i.e. choke partially closed).

If you have a slow opening choke, there is a possibility that the water housing is covered in a lime (like) buildup, which acts like insulation to the thermal control sensor. I found that filling the water housing in the carb with straight radiator flush and letting it sit for 15 minutes or so helped desolve some of that buildup and helped speed the choke opening time or got it closer to the original opening time when the vehicle was new. Of course, flush out the radiator cleaner after 15 minutes since it is a minor acid type cleaner.
OK,worth a try. Thanks much for the help!
 

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Would some CLR work too? You know, calcium, lime and rust remover.
 

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Mike, I ran across an 88 Dodge Ram 50 in the junkyard today and almost pulled the carb. It was in "okay" looking condition, but I didn't know if you'd want to buy that or not. Let me know and I may go back next week and grab it if I need to make another trip. I didn't look inside to see if it was a stick or automatic, in case that matters to you. Definitely an 88 model 2.6 though. I did check the sticker under the hood.
 

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I had a 2.6 Caravan many years ago that ran great, a previous owner installed a Carter 2 bbl from an older 318. I could see the carb base had been slightly ground as the mounting holes were a bit off. The accel and kickdown cables seemed to be a direct fit.

Thanks
Randy
 
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