Started the "Transmission Job"

[W_A_Watson_II]

Yea, was worried about the same thing, will need to check it for spline engagement at full drop. The CV joint is just out of view in the picture.

[Duke Winch]

That's my old "universal" drive shaft. It has a lot of splines on it so it accommodate a variety of shaft lengths. So it may not be as bad as it looks. But I' with Dave, I would definitely be taking some measurements at full droop.

Duke

[W_A_Watson_II]

At full drop, how much (inches) of spline engagement should I look for at a minimum?

Here was my estimate of spline engagement back in October before I had it all back together:

[W_A_Watson_II]

I re-checked the angles, and I do have a 9º difference. Plan on doing a 6º ship, as a little more weight and a 1" longer shackle will take a degree or two out.

Also at full drop (~4") I have 2.125" of spline engagement. Specifications I can find are 1.5 x OD (1.375OD) of 2-1/16" and a general rule of 2". So it seems like I'm OK. The shim should help a little, but the 1" longer shackle will hurt a little, for a probable wash.

Any thoughts?

[W_A_Watson_II]

The final Rear Drive shat spline engagement (before pinion angle adjustment) is 2.375" at ride height and 2.0" at full drop. I've ordered 6º shims to bring the rear drive shaft alignment to 3º delta at current weight and shackle length.

Started on the front fender modifications. Since I'm going to just go with the TJ flares for now, and make my tube fenders later, I'm trimming the front fenders close to what I'll need in the future that will still allow me to install the flares. The TJ Flare will extend further rearward than I plan on, so there will be some fender exposed inside the wheel well. I'll also have to shorten the flares front overhang to align with the bottom of the YJ fender. I picked up and installed the windshield. I then installed the sound bar and bikini top. I also installed the rear tail lights and swaybar disconnect links. A lot of fender work left, but that is where the majority of the work is left to do.



Will

[wdln]

Seeing the driveshaft pulled apart, the splined half is longer than I thought it was. So it's not as bad as it looked initially. Worst case, you run it until it fails (which it may never do) and replace it with something a bit longer. It's not like you're going to do anything TOO crazy with that YJ, right? It would scratch the nice paint!!

How much spline engagement is there at normal ride height then?

[W_A_Watson_II]

Dave,

True, that is on the replace it when/if it comes apart. However I do plan on having fun with the YJ, but will have to replace the axles before I can do any serious fun (Dana 35 and 3.07 gears won't be much fun). The axles are likely to fail with around 240 HP and 315 ft/lbs of torque before I get a chance to pull the drive shaft apart. As for the nice paint, I went flat rather than gloss to help hide the scratches and make it easier to touch up. But yes I will enjoy it some before playing hard with it.

Will

[W_A_Watson_II]

Worked on the fenders again today. Finished the drivers fender cut and patched the rusted areas. I also started on the passengers side fender, fortunately it's not as rusted.



Will

[W_A_Watson_II]

Finished the fender modifications and repairs, as well as the final fit and attachment points for the TJ Fender Flares. I've not got the bare steel on the fenders primed, and will likely spend tomorrow sanding, filling, repeating in preparation for what I hope is painting the next day.



Will

[W_A_Watson_II]

Well, started out the sanding, filling, sanding, repeating. However the third coat of body filler didn't set up very fast, and I eventually gave up, and scraped it off and re-applied. Apparently I didn't get enough hardener in it. While I was waiting I did install the mirrors, and started the rear axle shim install. Just need the longer spring pack bolts to finish the shim installation.



Will

[W_A_Watson_II]

Long Day of sanding, prepping and painting on the front fenders. Outer Color paint is on, now to paint the engine side gloss, and the fender wells black. While waiting on the fill primer to dry, I tackled the rear pinion shim installation. I had a 9º misalignment and bought 6º shims to get it close. Well, with the 6º shims, the rotation of the pinion also moved it up approximately 1-2/3". This meant the pinion angle was now approximately 1º too for in the other direction! So after some measuring and drawing, I've discovered to correct my 9º angle issue, I only need 4º shims. This will bring the pinion to within approximately 2º of being aligned, which is about perfect. If I then add the 1" longer shackles it should be about 1.5º off, still in the correct direction and acceptable.



Will

[W_A_Watson_II]

Well, I replaced the front axle U-Joint that was bad. Had to go back to O'Reilly's to get a good complete U-Joint, but while I was there I also picked up the needed wiper blades. I also painted the inside of the fenders black, and the engine side Gloss Tan. Additionally I also connected (not mounted yet) the marine amp for playing music from my phone or MP3 player. Tomorrow I hope to install the fenders, wiper blades and attach the Jeep decals. That will leave me with needing the front fender side lights to be legal.



Will

[W_A_Watson_II]

The weather warmed up, and I put 33 miles (for a total of 37) on the Jeep on the road today after installing the side markers. The Jeep exhaust volume has moderated downward, and the A/F ration is a little better. At road speed it's bouncing between 14.3 and 15.5, it does bounce more than I expected. It did developed a miss at speed after it warmed up, but it wasn't predictable or re-creatable or always there. Also on hard full throttle acceleration, it also misses some above 4,000 RPM before it shifts. I'm thinking I might have a fuel delivery/pressure issue.

[W_A_Watson_II]

Took the Jeep to the Exhaust Shop to get a 2.5" tail pipe made and installed. I'll need to trim the rear off so it doesn't extend beyond the fuel tank and spring, but they were able to tuck it up high enough. The bends do add some restriction, and the addition of the tail pipe, along with some run time on the engine/muffler has toned it down so it's not as loud. I also need to install the tail pipe band clamp once I trim the tail pipe. I did experience the miss again, after the engine get up to good running temperature. I watched the A/F ratio, but it bounced both high and low on the miss. Also the miss was there occasionally at idle, so I'm think perhaps more plugs than fuel.



Will

[W_A_Watson_II]

First, it's amazing how much quieter the Jeep is with the tail pipe and the plug gap closed down a little. It still sounds good, just not as bad a$$ as before.
I pulled the tail pipe out after marking where to trim the exit end. I then cut and cleaned up the ends and pipe before painting it. Once dry, the Pipe was re-installed and checked for exit clearances. As long as nothing gets between the spring and fuel tank it should be relatively safe.
Based on how the Jeep ran yesterday, and that the miss seems to come on after the engine was well warmed up, and the miss was present at any engine load/speed and not consistent, I believe the issue is plugs and not fuel. So I pulled the plugs. They were a strong 0.055" gap that I initially set them at, and looked decent. Plug 3 looks whiter, while plug 5 is darker, but "I" don't see anything that tells me anything. Based on others knowledge and comments, I decided to close the gap up some, so I re-gaped them to a strong 0.040". So I start the Jeep up, and the A/F ratio gauge doesn't bounce around nearly like it did before at idle. So I take it out for a test drive. Everything seems good, the Jeep sounds quieter, and the A/F ratio gauge doesn't bounce near as bad as it did before, even at engine speed. Well, once the Engine was well warmed, the miss was back, and again at all engine loads and speeds. Not consistent like it's a single cylinder, and it's very very bad at had acceleration once it tries to exceed 4,000 RPM. I watched the A/F ratio gauge and when it misses now it seems to bounce more to the rich side, suggesting (to me) that it's still a plug problem. The plugs are NGK BKR6E-11 (yes "E", not "3" as written on the cardboard). The stock plugs would be Champion RC12LC4. Based on what I've found the NGK's I'm using are one temperature range cooler, which is what was a recommended starting point for my stoker. So now do I go one more step cooler?



Will

[mrock24]

Just a quick thought. I had this exact same problem in a marine application a few years back. On a brand new high horse sbc it ran great for break in. Change fluids and plugs per engine builders specs. Engine warmed up great and then would miss under load and while idling. After hours of troubleshooting we swapped plugs again with exact same NGk plugs. Problem solved. Was informed by the builder later that one of the plugs had a tiny crack in the porcelain that when heated would expand and caused the miss.

[W_A_Watson_II]

Thanks, thinking of switching brands as well. Just want to start with a good plug number and see how it works.

[mrock24]

For what it's worth I have run NGk in every boat I've had with zero problems and they last forever and I am hard on marine engines. That said the issue with that particular set was probably caused by either me on install or the parts guy dropping them. Good luck. Hope it's just a simple problem. This has been a great write-up.

[W_A_Watson_II]

After installing the NGK BKR7E-11 (Gaped at 0.044”) I took the Jeep out for a spin. A/F Ratio seems even more stable. However it started missing even before it warmed up. Might have just been new plugs, but nope. A few miles down the road I got on it. Missed at high RPM, at 4,000+ RPM, A/F ratio in 10-11.5 range (rich).

Here is a video, you don’t hear the miss in 2nd at 5,000 RPM and 80 MPH: http://www.youtube.com/watch?v=fhNnI5RTJ4w

Here is another video of the same, I let off the throttle so it would shift into 3rd, as it wasn’t in the previous video: http://www.youtube.com/watch?v=eZsmQXNfjVY

Here are three videos at road speed 50-55 MPH, you can kind of hear the miss and see the A/F ration swing left (rich) when it does, at least that’s how I read it:
http://www.youtube.com/watch?v=8tZlC6At9cU
http://www.youtube.com/watch?v=EXUcQip7qdw
http://www.youtube.com/watch?v=tB8zs9Z-Qto



Above is a random plug (#5) I pulled after getting home. Engine was well warmed, and missing, and running at 2,250 RPM when I shut it off and pulled the plug.

Now I wonder where I go next? A/F Ratio at High RPM is Rich, and in the normal range while driving, so I’m still not convinced the miss is fuel related.

Will

[Fraser]

Will - it seems to make sense that the A/F ratio would be rich when a miss is present, as the fuel is not being burned fully or at all in at least on cylinder. I think I'd turn my attention to the distributor next.

[W_A_Watson_II]

I'm going back over my notes and research, and I'm think the plug recommendation I got from the Strocker community is wrong. They recommended the NGK BKR6E-11, but it's tip did not protrude as much as the stock plugs, see image below.



In doing some part number cross referencing and deciphering I think I need the NGK BPR6ES-11 as it's a Projected Insulator
Type plug like the stock Champions.

Might still not be the answer, but if the spark isn't deep enough in the combustion chamber, I can see it causing a miss.

[W_A_Watson_II]

Tried the stock Champion Plugs with out and with the old coil, and the miss is still there. The 2nd gear 5K miss in the one video where it doesn't shift to third is the rev limiter, but I do still get misses under hard acceleration once the miss appears.

With the stock plugs fresh I started it and a miss was quickly there, then as the engine warmed up it was gone. several miles and good runs and all seemed well. That is until I ran for a short distance in 2nd at 3,500 RPM and 55 MPH, as soon as I put it up into 3rd, the miss was there and very prominent.

Once back at the shop I let it idle and checked for misses and any leaks, none. I rev it up to about 4,200 RPM and the miss is there, drop back to idle and it's gone. I've shut it off at 2,000 RPM, and will pull the plugs for one last check before I start looking else where for the issue.

Frustrated,
Will

[wdln]

What's your distributor like? Years ago mine had a lot of slop in the drive gear (on a 258), and the motor would miss and stumble all the time. Replacing the distributor smoothed it out quite a bit.

[W_A_Watson_II]

Distributor is New, my old one had a worn oil pump drive tang, and needed a new gear to not void the cam shaft warranty, so it was cheaper to install a complete new unit .

[W_A_Watson_II]

In going back over my notes and research, and I think the plug recommendation I got from the Strocker community is off. They recommended the NGK BKR6E-11, but it's tip did not protrude as much as the stock plugs. In doing some part number cross referencing and deciphering I thought I needed the NGK BPR6ES-11 as it's a Projected Insulator Type plug like the stock Champions. However it wasn't. So I went back with a set of stock Champion RC12LYC Plugs. The miss started again cold, but it cleared up. was it because of just being new plugs? Well no, the miss did eventually come back just as before. I tried the old coil and the miss was still there. I pulled the plugs, again with a hot engine and running 2,250 RPM. the looked OK to me, except for a small imperfection on plug #3's insulator, a defect/crack? It's getting replaced.



The fuel pressure gauge test kit was out on load at the Auto Parts store, so I decided to go ahead and install the fuel pump anyway. The pump looked to be the original 1993 Bosch pump, and I found some debris in side the strainer, so it might be having problems. Well, the new "I call generic" pumps the auto parts store had in stock fit like crap, the pump was loose and would surly rattle. So I'm waiting on a new Bosch which I should have tomorrow. I spoke with the machine shop that did my block/head work, and the guys at the parts stores, and they suspect I might have an intermittent air leak. guess as soon as I get the pump back in and re-install the stock plugs, I'll see what I can track down next.



Will