Green Mesa XJ Posted November 5, 2017 Share Posted November 5, 2017 Absolutely right, however when I did the carb upgrade it was still a high altitude jeep in Colorado so had emissions and that damn AIR pump. When I pull the engine for my 30 year rebuild (yes running behind schedule on that) I'm planning to get rid of the last of the AIR piping and clean the vacuum lines up to the minimum required. I've seen a 2.8 cleaned up this way and it was a huge difference. From a tangled mess to clean. Link to comment Share on other sites More sharing options...
carnuck Posted November 6, 2017 Share Posted November 6, 2017 I would have gone to a TBI from an S10 while you’re at it. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
AMC86Kid Posted November 6, 2017 Author Share Posted November 6, 2017 My distributor does not have a vacuum line it is electronicly controlled Link to comment Share on other sites More sharing options...
Jeep Driver Posted November 6, 2017 Share Posted November 6, 2017 4 hours ago, AMC86Kid said: My distributor does not have a vacuum line it is electronicly controlled THIS is your problem. Get a simple vac advance dist. Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted November 6, 2017 Share Posted November 6, 2017 THIS is your problem. Get a simple vac advance dist. I believe the computer is why the engine has been “hard to tune”.And why the last owner thought the Federal emissions carb would be a upgrade that made it tunable.AMCKid did that Autoline D2100 distributor check out? Sent from my iPhone using Tapatalk Pro Link to comment Share on other sites More sharing options...
Jeep Driver Posted November 6, 2017 Share Posted November 6, 2017 2 minutes ago, Green Mesa XJ said: I believe the computer is why the engine has been “hard to tune”. And why the last owner thought the Federal emissions carb would be a upgrade that made it tunable. AMCKid did that Autoline D2100 distributor check out? Sent from my iPhone using Tapatalk Pro I've been watching this and I've stayed out of it. I'm aware of the early electronically controlled carb/dist, I have no idea what he is working with, what parts, what years, what works, what doesn't........that said, it was junk in 1985 and it's junk now. He/you need to simply your mess. He's been dealing with this for two months now, something that should have been rectified in an afternoon. Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted November 6, 2017 Share Posted November 6, 2017 I've been watching this and I've stayed out of it. I'm aware of the early electronically controlled carb/dist, I have no idea what he is working with, what parts, what years, what works, what doesn't........that said, it was junk in 1985 and it's junk now. He/you need to simply your mess. He's been dealing with this for two months now, something that should have been rectified in an afternoon. All of the computer controlled carburetor setups were junk, had a chrystler 318 with a “spark control” computer that never worked correctly, going back to the late 70s distributor fixed that mess. Even Honda had a convoluted carburetor system, all because the federal government imposed arbitrary emissions requirements. With a simple carburetor and new catalytic converter these old engines run much cleaner than with all the old emissions crap the engines were never designed for. And more fuel efficient too, used to get 26 mpg on the highway driving from Co to Fla a couple times a year. When these kind of carbureted setups have problems it’s: computer, o2sensor or wiring. Going back to basics usually fixes it.Sent from my iPhone using Tapatalk Pro Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted November 6, 2017 Share Posted November 6, 2017 I would have gone to a TBI from an S10 while you’re at it. Sent from my iPhone using Tapatalk Either that or a Holley kit. Sent from my iPhone using Tapatalk Pro Link to comment Share on other sites More sharing options...
AMC86Kid Posted November 7, 2017 Author Share Posted November 7, 2017 Currently the electrionicly controlled distributor I have works fine but after I get the new carb on there and test the engine a little I will call rock auto and ask them about the one vacuum controlled diatributor that they have so yes I do plan on getting a new distributor just haven't got there yet Link to comment Share on other sites More sharing options...
AMC86Kid Posted November 7, 2017 Author Share Posted November 7, 2017 Thanks for uploading the pics Green Mesa so i looked threw all the info and i have a basic understanding of what i have to do but here is a list of all the questions i have ... Here are basic pics of the new carb for reference: Ok so correct me if I'm wrong this is whee you connect a vacuum line from the distributor this is where you connect the PCV valve or the exhaust that comes from the valve covers also the fuel line goes in on the port in the far right of the pic as for my brake booster line it looks like mine just goes from the brake booster to the back of the engine Link to comment Share on other sites More sharing options...
AMC86Kid Posted November 7, 2017 Author Share Posted November 7, 2017 also what is this port for ? is it for the PCV valve on the other side of the engine ? do i connect my gas / throttle cable to the one on the right and my down shift tranny cable to the one on the left ? i beleve this is the gasket between the carb and the engine but what way does it face for installation ?? i will look in the book to see if it mentions it anyways as always thanks for reading guys and thanks for any help hopefully i will get this up and running today Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted November 7, 2017 Share Posted November 7, 2017 On that gasket I believe when you pull the old one it will be self evident, I think the printed number side was up.Brake booster line is the same as mine, goes to the back of the intake manifold. The front vacuum port on the carb was for the distributor. Guess just block it with a rubber stopper until you need it.I’ll have to look at the rest later. I think there might be a second design with a second vacuum line at the back. Do the instructions mention how to route the lines? Sent from my iPhone using Tapatalk Pro Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted November 7, 2017 Share Posted November 7, 2017 On the throttle cable on the bracket the inner is for the throttle the outer is for a spring that attaches to the factory valve cover.I don’t have that second big vacuum port at the back, not sure where you should run it to, probably run it to the vacuum port directly behind it or run it with the other big line in the front.Sent from my iPhone using Tapatalk Pro Link to comment Share on other sites More sharing options...
AMC86Kid Posted November 7, 2017 Author Share Posted November 7, 2017 Not really it comes with "Typical Install Instructions" so it just list what you have to connect, it dosent specify any specs for specific model vehicles Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted November 7, 2017 Share Posted November 7, 2017 According to the instructions online the rear is a pcv, front top is supposed to be fuel bowl vent. Sent from my iPhone using Tapatalk Pro Link to comment Share on other sites More sharing options...
AMC86Kid Posted November 8, 2017 Author Share Posted November 8, 2017 So the rear on goes to the valve covers but what does the front one go to I don't know what a fuel bowl vent is and how should I wire the choke from scratch Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted November 8, 2017 Share Posted November 8, 2017 Do you still have a charcoal canister? Should be by the radiator. mine routes there eventually after going in to a mess of pipes Sent from my iPhone using Tapatalk Pro Link to comment Share on other sites More sharing options...
zomeizter Posted November 8, 2017 Share Posted November 8, 2017 Feedback carburetors and electronic advance dizzies are not junk when they work properly, but they surely are delicate. A simple vacuum leak can wreak havoc on engine management and if one does not have the proper diagnosis ability, components will "act" defective, they will get replaced only to have the anomaly still exist, then frustration builds and it all becomes a POS! To seasoned Technicians like some of us, the cause of the problems the OP's vehicle is having would already be pinpointed and most likely resolved...my point? Maybe it's time to locate a good Tech to help 86Kid at his locale... Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted November 8, 2017 Share Posted November 8, 2017 this picture is from lunghd on his 2.8 to 3.4 swap http://www.lunghd.com/Tech_Articles/Project_XJ/Project_XJ.htm Yellow arrow is the factory plug for the electric choke, if you can find it and verify it is power one with ignition use it, or find another wire that is hot only with ignition on. Green arrow is the factory vent tube. Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted November 8, 2017 Share Posted November 8, 2017 18 minutes ago, zomeizter said: Feedback carburetors and electronic advance dizzies are not junk when they work properly, but they surely are delicate. A simple vacuum leak can wreak havoc on engine management and if one does not have the proper diagnosis ability, components will "act" defective, they will get replaced only to have the anomaly still exist, then frustration builds and it all becomes a POS! To seasoned Technicians like some of us, the cause of the problems the OP's vehicle is having would already be pinpointed and most likely resolved...my point? Maybe it's time to locate a good Tech to help 86Kid at his locale... You have a point. The electronics do not have to be the problem, I've had plenty of them be trouble best were the Japanese cars, worst was that Chrysler 318. I stand by saying factory carb on the 2.8 is complete garbage. The history of the MJ is a bit of a mess from what I understand and I don't know I actually understand it. Apparently the previous owner had problems with "tuning the engine" started the conversion from California emission and computer but never finished it, bought a rebuilt 3.4 motor to put in it but never did it. AMCKid did, from the pictures I've seen he is missing a lot of the factory vacuum lines and a few other things the 2.8 motor should have, I'm not sure there is any going back to the factory setup for this jeep, but I'm just a guy trying look at information online long distance, I'm sure a local mechanic who knows his basic could get it up and running correctly. Link to comment Share on other sites More sharing options...
AMC86Kid Posted November 8, 2017 Author Share Posted November 8, 2017 I'm doing just fine by myself I'm just learning how things work and what better way to learn then by restoring a comanche (am i right) any who i got the new carb on there and i was able to get the motor to run with the new carb no problem i will have to agree with Green Mesa the new carb is simple to use and works great, therefor its better then the old varajet carb and thats probably why it cost twice as much as the original carb also i put the carb gasket with the part number facing up, the instrustion book did not specify what side was up and the old one was the same texture on both sides so it was not the same as the new one (texture wise) also i need to get another PCV valve to plug into the passenger side then run them to a tee and connect them to the rear vacuum port then i need to put the charcoal canister back in there and connect the front vacuum port to that so basically to make it simple two PCVs to the rear and one charcoal canister to front does that sound right? gas seems pretty simple i will have to just add a filter and the distributor port is plugged for now until i get the vacuum controlled distributor last thing i would like to add is the choke so Green mesa are you saying that you need to send it 12 volts when starting the car then once its running you let go of the key and the voltage drops back down to zero am i correct on that cause i can always rewire the choke to work with a new ignition switch i just need to know how its designed to work and thank you for your help tomorrow i have to see if i can get a engine timing pointer indicator so that i can properly set the timing with a gun/light anyone have any clue where i can get on thats correct for my engine ? Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted November 8, 2017 Share Posted November 8, 2017 You need a power source that only comes on when the engine is supposed to be running so the choke adjusts only when the engine is on otherwise can drain the battery. If you can find the original plug for the factory choke you could use that since it should power up at the right time. Just splice the wire with the one included in the kit and run it over to the new choke.Sent from my iPhone using Tapatalk Pro Link to comment Share on other sites More sharing options...
AMC86Kid Posted November 8, 2017 Author Share Posted November 8, 2017 ok so i need to send 12 volts to it when its running then turn off the voltage as the engine turns off thats simple i can do that now for the two larger vacuum ports are you sure the one in the front goes to the charcoal canister and the one in the back goes to the pcv valves? in the original pics you posted you have the driver side pcv valve connected to the front vacuum port then it tees off and runs toward the charcoal canister so I'm confused where each line should correctly go is there any manual that goes into more detail about this specific carb? Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted November 8, 2017 Share Posted November 8, 2017 My Weber 38 does not have that port in the rear. According to the instructions it’s pcv, the fuel bowl vent in the front on mine does link up to the pcv but also has other lines going to the purge canister in the front. It’s had to show because it a mess of lines and there is are metal lines there running along side the cylinder head and intake manifold. If you have the factory lines still you might have the oem fuel bowl vent line still there, however I don’t think I saw the canister in the photos. Sent from my iPhone using Tapatalk Pro Link to comment Share on other sites More sharing options...
AMC86Kid Posted November 8, 2017 Author Share Posted November 8, 2017 well this is what i will do then i still have the charcoal canister http://www.rockauto.com/en/moreinfo.php?pk=45267&cc=1181393&jsn=387 i will run back port to a tee and connect the tee to the two pcv valves then connect the front one to the charcoal canister but I'm not sure which port to plug it into on the canister do you ? Link to comment Share on other sites More sharing options...
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