Tuning tips

[TWhetten]

My M715 has a AMC 258 in it, and I can not get it to run right. It runs fine if it is wide open. but it won't idle very well and mid throttle it kind of chugs then tries to die. If I keep bumping the throttle it will stay running. I have checked for vaccum leaks and have turned all the screws(probably made it worse). Any tips? The carb is a Carter if I remember right(everbody said it was not he most desirable carb).

[DNL]

The idle mixture screws should be out about one and a half turns. If it still doesn't idle, and the mixture screw position makes no difference, you have a vacuum leak, even if it didn't show up in a check.

Dave

[Binford]

I've never tried this trick, but it might be helpful to you:

http://jeep.off-road.com/jeep/articl....jsp?id=277064

I've always resorted to just rebuilding the stupid Carter BBD on mine. And now it's time yet again, from the way my CJ runs. Or won't run, as the case may be...

So this is what I'm considering this time around:

http://www.bustedjeep.com/projects/junkyardtbi.asp

I found a TBI setup in my local boneyard for $150.

Good luck! And hey...how do you like that engine in the M715? Bolted up to the T98 okay? Or does it require adapters?

[randyscycle]

Are you getting any black smoke from the exhaust? It could indicate a rich condition. A sticking float or float level set too high can be the cause.

Also, is the carb new, old, rebuilt? Maybe the idle circuit is plugged. If it runs when you bring it off idle, then it is running on the main jets at that point and the idle circuit is no longer being used. As stated above, be sure to set the mixture screw (the one all the way on the bottom) at 1-1/2 turns from lightly seated.

Also be sure you have a mechanically sound engine with good compression, proper timing, and no other major problems. All the carb adjustments in the world won't fix a worn out motor.

[randyscycle]

I've never tried this trick, but it might be helpful to you:

http://jeep.off-road.com/jeep/articl....jsp?id=277064

I've always resorted to just rebuilding the stupid Carter BBD on mine. And now it's time yet again, from the way my CJ runs. Or won't run, as the case may be...

You may want to look into a Motorcraft 2bbl. There is a company that sells a conversion, but basically all the kit is, is a manifold adapter you can get at any auto parts store and a Motorcraft 2100 (?) 2 bbl off of any mid to late 70's truck or car. A very simple and reliable carb.

[Binford]

I have a Rochester 2G carburetor that has the exact same mounting surface as my Carter BBD. So it's a bolt-on replacement and a pretty good carburetor. (Throttle linkage needs to be altered though--the 2G pulls off the back while the BBD pulls off the front. Or is that vice-versa?) If I don't do the TBI swap, I'll put that on my CJ.

[TWhetten]

Thanks for the replys,

Binford, that first link sounds exactly like what I need to do. I will try it this evening a let you guys know if it works.

Randy,there is no black smoke, but it smells like it is running rich. I am sure the engine and timing are fine, I will also recheck all the vacuum lines.

As far as it working in an M715 I think it works great. This jeep has been worked hard. It has spent the last 10 of the last 15 years pulling horse trailers, hauling feed blocks, or hauling around cake feeders and has always had more than enough power. I burns no oil and until this has been pretty much trouble free. It has alot more power and gets better milage than our other M715 with the tornado, and has outlast three tornado engines in that jeep.

As far as bolting up to the T98 it looks like it bolted directly too it. The engine mounts look like they were changed, but other than that it looks like an easy swap.

If I can't get it running right I guess I will start tearing it down and stick the cummins in it. I was going the wait till next winter, but I am tired of messing with it. It has a brand new starter and alt. if anybody is interested in the drivetrain, if not I might try to find an old CJ to stick it in.

[TWhetten]

Binford you da man, I did that first trick in the first link and it worked. It was really easy to do only took about 15 minutes. I guess the 258 can live in the M715 a little longer.

Randy you da man too, I set the screws to 1 1/2 turns and it has never ran that good I had them out alot further than that.

Thanks guys

-Ty

[Binford]

Hey, I said I've never even tried it! Just have it saved in my "bag o' tricks" file is all!

Glad to know it worked. I may just try it myself now!