Completely eliminating EGR

Picked up a great ram 50 over the weekend. Overall the truck is in good condition however right off the bat I know the exhaust needs to be replaced (muffler and a few other places have rust holes) and the truck has a bad hanging/high idle (especially when it warms up to operating temp).

I'd like to eliminate the EGR/smog system for a few reasons:
1.) I dont have to pass smog/emissions with this truck where I live
2.) I suspect some part of the smog/EGR system is responsible for this hanging idle and why keep it if I dont need it
3.) If I have to replace the exhaust might as well replace the header as well to elimnate the smog system it has built into the stock exhaust manifold
4.) Clean up the engine bay and uncomplicate things
5.) whatever this hanging idle issue is I think its hurting my mpg's..which is never good!
Mostly 1 and 2..

So has anybody done this? More importantly, can I do this without upgrading to a weber carb and keep the stock mikuni by just plugging ports without loss of functionality/performance?

Any info is much appreciated!

The choke is sticking. You need to look at that first and get it freed up so it won't be on high idle.

You can get an egr blockoff plate on ebay for under 20 bucks, or make one yourself.

When I got my 89 it had a really high idle also. I found that the idle mixture screw was missing. :wtf:

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Originally Posted by TheProspector

More importantly, can I do this without upgrading to a weber carb and keep the stock mikuni by just plugging ports without loss of functionality/performance?

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You can but you'll still have the 15 million spaghetti vacuum lines everywhere in the engine bay. There's no reason not to get a Weber, it boosts fuel mileage and power, sounds nicer and is much more easy to tune than the OEM. Get a Carter fuel pump though if you upgrade, the mechanical pump puts out too many PSI. You'll have to make a block off plate for the mechanical pump hole.

Removing smog stuff is as easy as unbolting it and throwing it in the trash and plugging whatever threaded bungs or vacuum ports are left over. You can't really break anything by removing emissions equipment.

Makes sense I just wanted to be sure. I eliminated the EGR on my old mustang and other than needing a retune it ran well.

Anyhow, camoit I took some pictures of the carb (what a mess! so much stuff hanging off of it) and wanted to know where exactly the choke is on this thing so I can see if its stuck or not. Not very savvy with carbs, Im used to throwing a part on then having to retune it via a hand held versus making some adjustments to a carb!

Truck idles so high right now when it warms up it has some runaway when you shut it down.

http://i301.photobucket.com/albums/n...ps34903d30.jpg

http://i301.photobucket.com/albums/n...ps9c5dcc77.jpg

http://i301.photobucket.com/albums/n...psea7df626.jpg

http://i301.photobucket.com/albums/n...ps94aae430.jpg

From the pictures I can see it's an electric choke. There is a round black thing on the side with a wire coming off it. That is the choke coil. It controls the opening of the choke. Pull the wire and turn the ignition to the run position. Then check it for power. If there is power just put the wire on. Let it sit there with the engine off and it will warm up. After about 3 minutes or so give the throttle a little snap. Then the choke should open. The choke is the plate you see at the top of the carb that covers one of the holes. If it does not open then there is a problem and we need to find the root of it. But the choke is adjustable via the screws that hold it on there. If you loosen them up you can rotate the choke coil cover and this will adjust how strong (Rich) or loose (Lean) it will hold the choke. If the coil is bad you can rotate the choke to lean and it will run just it's harder to start, tell you get a new coil.
The linkage it turns will go down to a "High idle" cam. There is a screw that it sits on that cam when the choke is engaged. It is adjustable. Make sure all the linkage moves free when the throttle is open, like you are running down the road.
The main thing that goes wrong is the linkage gets stuck, the coil burns out and needs to be replaced, or there is no power to it.

Look in the manual section > over 216 manuals > Montero this covers your truck.
In that manual there is section just on your carb. We are currently working on getting a manual just for the second gens.

Camoit your a wealth of information! Thank you.
Makes sense. Contemplating temporarily adjusting the choke plate to the point where its open permanently if it wont affect difficulty of starting the truck up too much. Thing is right now MPG's are terrible and the truck runsaway after you turn the key off...terribly annoying. Any idea how much harder it will become to start if I went this route?

I left my damn multimeter back in Baltimore, I can grab it next weekend and test the choke coil then. Lets say the coil IS bad, could I even easily obtain a replacement choke coil for the carb? That weber is looking better and better. I just didnt want to drop the coin on it right off the bat.

With the engine off, open the throttle by hand. Then push the choke plate open with your finger. Look at what direction the lever moves on the side of the carb. Then while holding the choke open, let the throttle close. Next grab a trusty Cable Tie and Zip Tie the lever in the open position. This will hold the choke open. Start truck. If it's real cold you might need to pump it and feather the pedal to keep her running in the beginning. But it will stop the engine run on. That is something you forgot to mention. That confirms the choke, bad MPH, black smoke, and high idle problem to me.

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Originally Posted by camoit

That confirms the choke, bad MPH, black smoke, and high idle problem to me.

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No black smoke, just high idle, bad MPG, and runaway after shutdown.

Before I went to school today I ziptied the choke wide open on her....Ran exactly the same with hanging/high idle and still had runaway just like before when I shut the truck down.

http://i301.photobucket.com/albums/n...ps0b40525b.jpg

I take it the next logical step would be to mess around with the high idle screw?

Looking closely at your pics I can see that the electric choke is still fastened on by the rivets so you'll have to chisel them off or drill them out and replace them with screws. That may involve tapping threads in the casting also. I also notice that the casting where the idle mixture screw is housed is chipped on top. Have a look in there with a flashlight and make sure you have a flat head screw slot showing and not just a small hole. If you don't have an idle mixture screw she'll idle at about 1500 rpm and will diesel when you turn off the ignition. You can get a choke conversion kit to change your choke over to a manual choke if you don't want to bother with the automatic one.

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Originally Posted by Andy 2

Looking closely at your pics I can see that the electric choke is still fastened on by the rivets so you'll have to chisel them off or drill them out and replace them with screws. That may involve tapping threads in the casting also. I also notice that the casting where the idle mixture screw is housed is chipped on top. Have a look in there with a flashlight and make sure you have a flat head screw slot showing and not just a small hole. If you don't have an idle mixture screw she'll idle at about 1500 rpm and will diesel when you turn off the ignition. You can get a choke conversion kit to change your choke over to a manual choke if you don't want to bother with the automatic one.

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Andy,

Either way the choke is wide open now. I cant see it being the problem now, if it functioned this is the position it would be in.

Is this the hole you are referring to? I dont see any other holes that looked chipped on top.

http://i301.photobucket.com/albums/n...pse5e0804f.jpg

No, that's not it. The Idle mixture screw is located near the base of the carb to the left of the dashpot. In the third pic on this page you can see the casting has a small chip out of the top of the mixture screw housing. There is a small hose just to the right of it. The fact that it is chipped suggests that someone messed with it and perhaps broke the casting in the process. If there is a screw in there it should turn freely with a bit of resistance as there is a small spring behind the screw that stops it vibrating loose. Like I said in my first reply, the idle mixture screw was missing from my 89 when I bought it and it acted very much like what you describe. There are instructions for setting up the mixture screw and the idle speed screw in the Haynes manual.

Andy,
Found the location you spoke of today. Flat head screw is definitely in there, havent messed with it yet though.

Im gonna try and download the manual again tonight, tried it a few days ago and my oustanding internet connection said I dont think so.

That's a good idea before starting to turn screws. There's one that's not supposed to be adjusted and the Haynes manual is pretty clear on why. I can try to scan my manual and post it for you but no guarantees. My connection is a dial up and pics and the like take forever.

That's a good idea before starting to turn screws. There's one that's not supposed to be adjusted and the Haynes manual is pretty clear on why. I can try to scan my manual and post it for you but no guarantees. My connection is a dial up and pics and the like take forever.

Sometimes it takes so long I forget that I posted and post again.

I went to the Mitsubishi manual and it said for engine dieseling:
1.) carb; idle speed too high needs to be adjusted
2.) FBC system; Slow cut solenoid valve malfunction

I adjusted SAS 1, the carb idle speed screw. When I adjusted the screw in I was able to get the idle to increase in RPM. However when I adjusted the screw out the idle would never go lower than the previous idle speed no matter how much adjustment I made. :rolleyes:

Thing is, even if the slow cut solenoid is responsible for the engine dieseling it does not explain the high idle that refuses to come down in RPM. The slow cut solenoid does not explain that part of the issue and it would make sense that they have a common cause.

have you checked you throttle cable adjustment? Perhaps it's too tight and won't let the throttle close.

perhaps this will help.


Attachment 5131Attachment 5131

I also notice in the third pic that one of the rubber vacuum line caps is coming apart. Something else that may cause your high idle and poor gas mileage would be where the vacuum advance line is connected. It should be on a metered vacuum on the carburetor and not a manifold vacuum. Manifold vacuum increases when the throttle plate is closed which would advance the timing at idle and provide no advance when driving.

Andy, I appreciate all of the input, I checked the throttle cable and it looked good. After that I just took it to the local shop I used to work at and let them have a look at it since I just dont have the time right now to really dig into things with the truck.

Dropped it off there two days ago and picked her up today. According to them the carb itself is shot and is leaking fuel internally causing the issues. They offered to get me a rebuilt mikuni but it would take a while to come in.

Obviously I have no desire to throw another mikuni on there especially when they want more for a rebuilt mikuni than a weber costs...

The cheapest place I can find the weber conversion kit for is 279 on eBay and its a DFEV. Anybody know of a cheaper source to buy the conversion kit? They say in the ad the DFEV is the electronic choke version, I am assuming this is what I want to go with since my truck came equipped with the electric choke?

Last thing, they want 250 to put the carb on and tune it. Doesnt sound like too bad of a price to me. I just dont know how difficult it would be to get it dialed in. Im pretty sure I could put it on myself though. So 250 for them to throw it on or free plus paying them 100+ to tune it if I cant get it dialed in:shrug:

Sorry to hear that. I was hoping it might have been something more easily fixed. www.webercarbsdirect.com sells them for the same price $279. Don't forget to add the electric fuel pump to your cost. What the Weber owners here are saying is the stock fuel pump will overpower the float. I don't have a Weber yet so I can't really offer any help.

Andy you and I both. I thought it may have just been some dumb easy fix I just couldn't see.

Have you checked car-part.com to see if any of the auto recyclers have a carb for your truck? You might get lucky. I think there's warranty on used parts as well. Around here I think they give you 30 days and you can return your part if it fails.

I have a Mikuni carb that ran great on an '87 Mits. I'll never use it...$50+shipping. Picture in the for sale section of forum. Has all the OEM equipment still attached.

my mighty max had a slow oil leak and a scary high sometimes irregular idle, i replaced the oil pressure switch sensor thing near the oil drain plug and i leak much less oil (thinking oil pan gasket, possibly rear main seal) but the idle went back to where it was. since i have also replaced the plugs and wireset and my idle is so low and consistent now, its just above dying. also might want to try cleaning your carb with carb cleaner. cheap easy and doesnt take long. best of luck

Brads deal sounds good. Probably won't be too much for shipping. Throw in ten bucks for a new base gasket and you could swap it out yourself in a couple of hours.