Many 2.6 troubles-low miles, dried parts

so, I've gotten a 79 d50 with the 2.6 it has 80k miles- I know right? only 80k? not 180k? I base this on the pedal covers being OG and nice, the vacuum hoses having the color stripes, the body is rust free and carries the original decals, the fuel hoses have braided cloth covering and don't leak, the Distributor cap is stamped Mitsibishi. It seems like an 80k truck.

There are some serious problems though- I'm not sure the carb is original-the vacuum ports that the EGR and other emissions systems go to are either missing or the nipples don't go to anything-plugged internally. The vacuum advance is broken, the engine burns oil with quickness, the transmission whines at idle in neutral. When starting, the engine will crank and then stall like it's locked up. Release, then try again and it starts fine, WHY?
I need to kill the jet valves. HOW? must pull head?
I need a new vacuum advance, plus pull the distributor and regrease it.
The clutch was rust welded to the flywheel, should replace? or since it's broken free now it's okay?
Carb without proper emissions-leave it or not?
Oil Burning- Valve stem seals? jet valve problem? hidden engine wear? I sure hope I don't have to tear apart this engine.
Crank and stall? HUH? I got nothing on this, it's a dynamic compression problem I suspect but WHAT?
Attachment 19475

Lots of folks remove the OE Mikuni carb and install a Weber. It gives better performance is the consensus. I never had a Mikuni only the Weber. Try doing a fluid change oil and trans and coolant if it's old then tune up cap, rotor, wires plugs, Coil. See how it runs then. If it is a Weber carb there should be a vacuum hose from the driver side bottom of the carb to the vacuum connection on the distributor.

Welcome aboard

You will find the oil consumption issue is dead valve stem seals. Age affects them as much as heavy wear does. Unfortunately I would recommend you take the head off and replace the valve stem seals (there is a short cut way to do them but if you drop a valve collet into the engine, you're pulling the sump off) but this engine has suffered from not being run at all so it would be a good idea to check that the head hasn't experienced corrosion through the galleries. Coolant turns acidic after a long time and it will eat cast alloy no problem. As for the clutch I would drop the transmission and give the flywheel a quick going over with an orbital sander just to score the surface a little. I doubt it needs machining but I would advise you to get another clutch disc just in case the rivets are wrecked. Give this thing a big service - engine flush and oil change, refresh the coolant. Check all the ground leads as they are a possible cause for difficult engine starting.

the starting issue could be something simple as a poor ground.....if the truck has been sitting for decades the oil consumption issue may fix itself as things re-seat....do you have pics? (you can receive more feedback from members)....fyi this is still available:

http://www.mightyram50.net/vbulletin...-6L-carburetor

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Originally Posted by 85Ram50

Lots of folks remove the OE Mikuni carb and install a Weber. It gives better performance is the consensus. I never had a Mikuni only the Weber. Try doing a fluid change oil and trans and coolant if it's old then tune up cap, rotor, wires plugs, Coil. See how it runs then. If it is a Weber carb there should be a vacuum hose from the driver side bottom of the carb to the vacuum connection on the distributor.

Welcome aboard

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Okay Its a Solex/mikuni. fits all the photos in the factory shop manual. problem is, all the vac ports for the egr stuff are dead/plugged- I can't draw anything out of them with a vac pump. the main intake vacuum port to the distributor is okay, but all the points that the manual says to connect for the air cleaner valve, the egr solenoid etc are plugged. there's three of them total. a tune up helped a bunch, the vac advance is shot. the starting thing is puzzling, feels like the engine just gets mechanically bound up- spins fast, then stops dead, let off the key, try again, spins fast and starts right up. I wonder if there is something rattling around on top of the piston. I'm gonna pull the head to kill the jet valves anyway.

Attachment 19481Attachment 19482Attachment 19483 see? low milage. I'll get some pics of the carb stuff in a hour or so.

Attachment 19484Attachment 19485All the vacuum ports indicated with arrows are dummies- they do not pass air from a pump, either suction or pressure. unless there is a solenoid that controls them all, which I don't see. Is this a case of someone rebuilding the carb and plugging them to pass a visual smog check? does anyone else have this carb and can check if they have free passages?

The second picture where the hose connects from the side of the valve cover to the inlet manifold is a breather hose and is in the right location. Is there a vacuum hose going to the distributor? The distributor needs a vacuum source from above the throttle butterflies or it would be getting constant vacuum. I have a feeling the port that has no hose attached is the distributor vacuum connection, and the one you have indicated below it connects to the EGR valve on the side of the manifold.

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Originally Posted by geezer101

The second picture where the hose connects from the side of the valve cover to the inlet manifold is a breather hose and is in the right location. Is there a vacuum hose going to the distributor? The distributor needs a vacuum source from above the throttle butterflies or it would be getting constant vacuum. I have a feeling the port that has no hose attached is the distributor vacuum connection, and the one you have indicated below it connects to the EGR valve on the side of the manifold.

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RIGHT! but NONE of them pass air. I don't know if someone blocked them, they just clogged up, or if they are supposed to be that way. the breather line from the valve cover for instance, WHY would that not pass air? that would make no sense- and a vacuum advance can't work if it gets no vacuum.

The line from the valve cover is a metered orifice that Mitsubishi used in place of a PCV valve in 1979 and 1980. That can become plugged in the valve cover - the line is to allow engine vacuum to suck fumes from the valve cover into the engine to prevent pressure buildup in the valve area. The manual suggests you to use a stiff wire or small drill bit to clear the orifice. The other lines may be part of the EGR / Sub EGR system, and it is probably carboned up as well by now - time to pull the EGR and see if the ports are clogged with carbon - very common on these trucks.

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Originally Posted by pennyman1

The line from the valve cover is a metered orifice that Mitsubishi used in place of a PCV valve in 1979 and 1980. That can become plugged in the valve cover - the line is to allow engine vacuum to suck fumes from the valve cover into the engine to prevent pressure buildup in the valve area. The manual suggests you to use a stiff wire or small drill bit to clear the orifice. The other lines may be part of the EGR / Sub EGR system, and it is probably carboned up as well by now - time to pull the EGR and see if the ports are clogged with carbon - very common on these trucks.

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NO, the ports AT THE Carb are plugged., the lines pass air at the valve cover and the egr opens with a pump applied, but the nipples can't pass air. It seems totally stupid!

The vacuum port without the hose attached is the connection for the distributor advance. It is intentionally restrictive. To be 100% sure it is/isn't blocked, grab a can of WD-40 with the straw nozzle and insert the straw into the port. Spray a shot into the port and you should see it leak out into the primary throat on the carb. This test is completely harmless and will confirm if it is open or not. Hopefully the advance solenoid on the distributor hasn't split. Is your truck engine the 4G52 2.0? Just OOC...

OKAy everyone, please pitch in. 1979 2.6, Federal emissions, original carb. anyone have a vacuum hose diagram that's better than the sticker underhood? can you guys go confirm what the three ports on the side of the carb closest to the left fender are connected too? one of them passes air into the intake, so the lowest one is manifold vacuum. the other two do not pass any air, they sat with a vac pump on them for 20 minutes-no drop in suction, the needle never moved. I suspect that if they are supposed to be used at all then they were plugged up on purpose and I'll need to pull the carb. so if I can CONFIRM they are supposed ot be in use on this model and what they go too, I can confirm I need to pull the carb. PLEASe- no guessing, if you have a '79 like mine, please take a look and tell me what's up.

If you look through this manual for the 1980 D50 chapter 14 page 9 starts discussing the carb and mentions vacuum hose routing without showing a diagram. It also refers to Chap 25 Emissions Controls I didn't read closely but you may be able to help yourself that way. I suggest you actually try inserting a wire or small drill bit or failing that spry in some WD or carb cleaner to break up whatever is plugging the holes as directed. The long time members on here aren't going to tell you to do something that will hurt your motor.
The Manual http://www.mightyram50.net/vbulletin...ory-manual-PDF I have a hard copy of the 85 manual and its pretty much exactly the same with a different cover.

I did look at that. there arent any good drawings or photos. I also have a'79 factory manual, same deal. I ran a bunch of carb cleaner into the ports and was able to open one of them, It's ported vacuum and I figure it goes to the distributor. now I only need to figure out the last port(is it really used or not) below the shut down solenoid, highest one in the photos, and the air cleaner. also figured out I need a new secondary vacuum can, mines got a hole in it.

I looked through the Chilton's (80200) I had after I posted. It has a lot of surprisingly clear pictures and diagrams of the carb but the vacuum diag for the 79 is ambiguous to me. IDK if that will help you but I figured it deserved a mention as you never see pictures that clear in a chiltons or haynes. Keep going through the site. A lot of guys say things in unrelated posts that are helpful for other issues. I know its a pain but ists something to do when no one is online to answer :)
EDIT- I GAVE THE WRONG NUMBER IT IS 20800

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Originally Posted by 85Ram50

I looked through the Chilton's (80200) I had after I posted. It has a lot of surprisingly clear pictures and diagrams of the carb but the vacuum diag for the 79 is ambiguous to me.

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would you scan that diagram? or point out a chiltons link? I have the haynes and factory, no help.

I just took these 17 pictures of what seemed like should apply to yours. There may be other info in the book. The first pic is of the vacuum diagram. This book goes back to 79 and that is the earliest year of vacuum diagram. EDIT- The photos got jumbled by the uploader. I numbered them 1 to 17 so you can work out which one follows which when I hit edit it shows me the pic with no number so I don't know which one goes where :) I just clicked a couple sorry for the blur. That was my cam EDIT-I GAVE THE WRONG MANUAL NUMBER IT'S 20800

Attachment 19513 Attachment 19528 Attachment 19527 Attachment 19526 Attachment 19525 Attachment 19524 Attachment 19523 Attachment 19522 Attachment 19521 Attachment 19520 Attachment 19519 Attachment 19518Attachment 19517 Attachment 19516 Attachment 19515 Attachment 19514 Attachment 19529

Here it is on amazon if you want to get it https://www.amazon.com/Dodge-Arrow-1.../dp/0801990890

If you are going for a restoration You'll want to make contact with MikeWarme, and noahwins for smog related stuff. Noah has a thread in 'tune and smog' he is a California smog tech who should be able to tell you about your lines and Mike has a lot of new old stock parts he doesn't want to sell to just any guy who can make due with something else. He's more interested in helping restorers. He might know stuff about the vac line IDK.

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Originally Posted by ragragtimetime

the starting issue could be something simple as a poor ground.....if the truck has been sitting for decades the oil consumption issue may fix itself as things re-seat....do you have pics? (you can receive more feedback from members)....fyi this is still available:

http://www.mightyram50.net/vbulletin...-6L-carburetor

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this turned out to be the serious timing problems of a seized advanced plate .

that will play hell with running for sure...

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Originally Posted by pennyman1

that will play hell with running for sure...

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yeah. I urge you all to go check the lube state of your dizzies, they might not get advance, the vac can might be shot. an hour with some lube and a bench teardown will free her right up.

Or running it every once in a while helps too - the dizzy sticking can be expected on a vehicle that has sat neglected for years...