Newb needs help with engine sputtering

I wouldn't say I am a total newbie since I have been into rock crawling for years. I have owned and worked on many full tube buggies and 1 ton rigs for a while now, but would not claim to be the best mechanic. I recently decided to sale my crawler and buy a totally restored 1968 Kaiser CJ-5 with a V-6 engine. This is all new territory for me. The problem I am having is the jeep sputters through most of the rpm range. It does settle down a little, but as soon as you switch gears or add more throttle the sputtering starts back. The jeep sputters the most when first taking off or when running low rpm's. I just bought the jeep and just got through giving it a good once over. All of the spark plugs, points, plug wires, and hoses are new. It seems to smell like it is running rich though. I figured that the carb needed to be adjusted so I tinkered with it a little, but it did not seem to help any. This is another one of those things that I don't have a good grasp on since all the rigs I have ever worked on were full injected or ran on propane. My other idea is that may be the timing just needs to be adjusted. I am sure this is probably a common problem with these jeeps, so I figured someone out there would be able to pin point it pretty quickly.

 

If it wasn't driven a lot, it probably has some deposits in the carb blocking or restricting some of the small passages. Remove the carb, then carefully disassemble it, keeping track of what goes where with many of the small springs, clips, check balls and weights, get anything rubber off of it (like the diaphragm) and then soak it in lacquer thinner and if its really bad, get some fine .020 wire (you can find it at craft stores in the jewelry making section) to chase out the small orifaces.

Put it all back together, put a fresh fuel filter on it, and it should run 100% better. These old carbs clog pretty quickly if you don't drive them at least once a month or so just to move the fuel through.

 

I will give it a shot tonight and let you knowhow it goes. Thanks for the help, I hope that is all it is.

 

I recently had the same problem, after rebuilding carb and replacing virtually the entire ignition system, found it to be the timing. I was running 5 degrees btdc but found by advancing to around 12 all hesitation and stumbling went away. hope you find your problem.R

 

Timing or dwell.

 

I am going to clean out the carb really good tonight. Then swap the fuel filter and then set the timing. Hopefully this should cure the problem. Will keep you informed on the progress tonight.

 

I'd recommend putting in a comprehensive carb kit. If it is the original Rochester, it is not that hard to do. Take pictures and take your time as you disassemble it. I'm no ace, but I think the only thing outside linkage you can adjust are the low speed jets. They probably don't make a lot of difference above idle, but again, I'm no genius.

The other issue would be timing,but manuals make that fairly clear--right?

 

Well I cleaned the carb and advanced the timing. It is running better once it gets going, but is still spitting and sputtering on take off. It also does miss a little at lower rpms still, but it is an improvement. Eventhough it seems to be running better, now I have developed a back fire every now and again. Really don't know what to do now.

 

You are right about that. The low speed jets do not make a whole lot of difference when you adjust them.

 

The only time my CJ5 has ever backfired was due to the plug wires getting mixed up and in the wrong firing order.

 

It just started since I adjusted the timing. I worked late tonight so I did not have time to work on it. I think my next step will be to check the points again and then the dwell. Although it does smell like it is still running very rich.

 

Well I went ahead and changed the points and the condenser just to make sure they weren't the problem. I set the gap to .16 and set the timing. It is still spitting and sputtering. I know it is getting plenty of fuel because I can smell it. Tomorrow I am going to pull all of the spark plugs and check the gaps on them.

 

If you have a multi-meter, you can ohm out your plug wires to make sure you don't have a bad wire also.

 

Well I couldn't sleep last night so I went into the garage last night at 12:00 am to pull the plugs and check the gaps. Everything looked good. Now I am up at 7:00 to go test the coil. I hope this is the problem I am running out of options. mehh

 

If this is a new vehicle to you, I'd recommend a compression check. This will give you an indication of the general health of the engine.

Also, if this is a new-to-you vehicle, I'd recommend replacing the plug wires. Plug wires are a common source of misfire, and it is hard to tell their condition by inspection. Even with a multimeter, you can't check the condition of the insulation. Replace them. I'd also recommend replacing the distributor cap and rotor, especially if they are black plastic. It's very hard to tell by inspection what the condition of the distributor cap is if it's made of black plastic.

The easiest test for your coil is to look at the spark from one of the detached plug wires. A weak coil will have a yellow or orange spark, while a good coil's spark is blue-white and jumps a 1/4"-3/8" gap easily. Pull a plug wire off and hold it near the block. Use something very well insulated for this, like two long sticks - I have a pair of plastic fuse-puller pliers I use pulling plug wires. Remember that the plug wires are suspect, so stay away from them too - don't assume that the plug wire insulation is good.

If you set the timing and dwell properly, yu have a strong spark, and the engine has good compression on all cylinders, the logical place to look next is the fuel delivery system.

 

Iv had the same problem with my jeep. I replaced basicly everything there is still signs of it running funky but its pretty good now. Keep at it and try not to make it worse in the process and keep track of what made it better or worse

 

This vehicle is new to me. I picked it up last weekend. The previous owner installed new plug wires, hoses, distributor, and spark plugs. I have installed new point set, condenser and changed all the fluids. I am going to use the method you described to test the coil. I also have been reading me Chilton manual and discoverd I need to advance my timing to 5 degress. It is just warming up enough to go down into the garage. Keep your fingers crossed for me. Thanks for all the responses they have been really helpful.

 

Geeez , i can't believe nobody suggested testing the vacuum advance on the distributer. according to some experts on this board a Dauntless v6 will barely run whithout one.

mike s.

 

So I installed a new coil and it did no good. Now I noticed while driving it around when I let off the accelarator one side of the exhaust back fires. I checked the plug wires to make sure none of them were crossed up. It doesn't seem to be a fuel problem because when I give it more throttle the motor smooths out. It runs really rough at lower RPM,s and then back fires really loud when you let of the gas. So here is my checklist if I am missing anything to check let me know.

New point set and condenser set with a feeler guage to .016
New coil
Checked spark plugs and gapped them to .035
Set timing to 5 degrees above top dead center
Cleaned out carb
Adjusted carb fuel mixture
Checked all plug wires
Checked distributor cap
Checked firing order


I will check the vacuum next any other suggestions. :?