Studder when accelerating

[absolutemoon]

Ok fellas, I am releasing the curse of the almost 500 post thread and starting a new one. Here is the deal for those of you who are not yet up to speed. I swapped the old carters with a mc2100 and added to it the hei upgrade. After finally coming to the realization that I should check my plugs and see if they needed replaced, then replaced, I had her running nice. She is timed at 10 and runs very well at cruising speed. What I am noticing is if I try to accelerate fast from stop, she will again try to stall. If I hold the brake and hit the gas to give it some power before letting off the brake, she will go with no hesitation. I also notice when I am making a turn and my rpms are down, and give it gas to accelerate out of the turn, she hesitates then as well. Thoughts? Accel pump? Carb adjustment? Not sure? Thanks guys, and I'll try to keep this one under 100. Bry

 

[bugleboy]

mines been hesitating on turns lately too its weird cause im stock under the hood, its like it just doesent want to go any faster in u-turns, doesent happen frequently but when it does happen it scares the crap out of me

 

[69jeepcj]

I would think accel pump adjustment. I would not start changing power valves, jets and all that stuff again. I would say its in the accel pump or carb adjustment. If you have a vac leak somewhere (just a small one) you may have to adjust your cab often until the leak is fixed. Im doing that with mine now until I can find the vac leak, I have to adjust it every couple days. My guess on mine is that the vac leak changes the amount of vac the motors pulling which affects the carb settings.

Start with the basics first:: check that your plug wires didnt come loose, and check the plugs again.

 

[superj]

That what mine was doing but I do have a blown power valve from a back fire and a bad vacuum leak.

Well, had all those. I pulled the carb and intake and starting putting the offenhauser to use with the 2100. Little did I know the iffy has a slightly different way of bolting up that either needs really long spacers to go down the exhaust manifold or do a whole lot of grinding to get the offy to use the same bolt and washer as stock. I chose stock so I had to grind over an 1 by 1 by 5/16 away from around each bolt hole and make sure there was a thickness of 3/8 to 1/2 at the washer land so the stock washer and bolt applied force equally. This was not fun. Anyways, the intake is bolted on and tomorrow the carb will go on in the morning so roller skating in the afternoon with my kids and jake (rock316) and his family can happen

 

[superj]

finally got everything back together and waiting for the kids to get here so we can go skating.

the jeep accelerates so smooth now and feels like its got more power. the power valve was not blown, i did the old fashioned way of testing and it held fine. i think the problem was the vacuum leaks and the bad transitions from all the adapters. anyways, previously, i could only get 17" on the vacuum gauge and now i have a hair over 20" again. starts perfect and drives well but i need to figure out where to set the trans linkage so it shifts well. i got hte linkage mounted to the offenhauser intake but there is zero way the carb and linkage will hook up. ZERO. so right now, i have the linkage set at a certain point using a bolt and nut and have did a little adjusting to try and get it where i like the shift point but its not there yet. it does shift though so i will work on it

i also need to do some work on the accelerator cable but it is driveable for now

 

[absolutemoon]

Nice!! I haven't had to do any adjustments to my linkage yet. I will look for signs of vacuum leaks though. I thought if I had a vacuum leak, I would notice it throughout acceleration, initial, middle and top end. This not true? I also thought I would see it on the vacuum gauge.

 

[superj]

you won;t see a vacuum leak in the higher rpms because the throttle plates are open alot.


well, a 20+ miles drive and it drove perfectly. started and idled fine each time. can get back up to 100mph again, if i try to. i got up to 85 to pass some truck and it still wanted to go more. 85mph is about 3100 or 3200 rpms.

we had a blast with jake and his family. his daughter is learning to skate and goes out in the beginner area with me and my youngest son. my boys both skate well enough but jarrod likes having someone his own age to do stuff with so it works out good.

 

[superj]

dooohhhh, forgot to tell ya'll this.

normally, at a half a tank, i am sitting at 100 miles on the trip meter. this time, on the mc2100, i am at 120 miles and still above the half mark. i have never seen the jeep get over 100 mile in half a tank, since i have owned it. so the mc 2100 does definitely improve gas mileage