Trouble with idle/timing

Hey guys,

Now that I have the drivetrain fixed up I've been working on getting her to run decent, or better yet just hold an idle. I've been doing a lot of searching here the last few days and found basically what I need to know, however I must be doing something worng because I've only been able to get a very rough idle for about 5 minutes until she dies.

Here's what I've done so far:

rebuilt Rochester 2bbl GM carb

new gasket to intake manifold

new delco distibutor, points, condenser and cap, (still have old rotor but looks to be in decent shape)

plug wires and plugs looks OK.



I've been thinking its a vacuum leak but I can't seem to find any? I removed the vac line that goes from the manifold to the heater controls and plugged that, the carb has all new gaskets, and the intake mani doesn't seem to be leaking? Are there any other places I should look?

Timing: I placed engine at TDC on #1, installed the dist. with the rotor pointing at 7-8 o'clock position as your standing in front of the grill pointed at #1 plug.

I can get the engine to turn over and run as long as I have the in-cab throttle cable pulled out a little, as soon as I push it in the jeep will sputter for while then die. In order to properly set timing I need to have a steady idle, right? But for some reason I can't get there. When I do have the engine running with the throttle pulled out a little I used the timing light (with vac advance plugged on both sides) to set the timing around 10*, if I go any lower it runs rough, it actually seems to run a little better advanced further say around 15*. Then when I push the throttle cable back in (no throttle) it won't run very good and timing drops to 5* or lower. So now I thought if I plug the vacuum advance back in it should run, well it does the same thing unless I have a little throttle applied, but with a little throttle the timing goes up to 20*+.

As I read the archives, it seems to me there must be a vacuum leak and thats why I can't get it to idle. I also thought the carb adjustments might not be right but the are both about 2 turns open and from what I read the idle may be rough but it should still hold an idle, and then I can set timing. then readjust the carb for a smoother idle.

Unfortunately I don't have a vacuum gauge or a dwell meter so those are two things I cannot check. I'm also pretty sure the timing components are new, but I need to make sure.

Any other suggestions or different things I can try?

Thanks!

 

Turn up the idle screw on the carb to get it to idle without the throttle cable engaged. Likelyhood is this may be your first problem. Then see if you can time it. If you have a tach, set idle around 650-700 and see if that doesn't help. Just a thought.

 

Is there another screw for idle besides the 2 on the lower front portion of the carb?

 

Ahhhh, Thanks Patrick! I was not aware of that ...hopefully that will help a little, I definitely need to get a hold of the FSM ASAP.

I'll let you know if that was the problem.

Thanks!

 

Well last night I installed a pertronix ignition, reset timing and adjusted the idle spped screw to get a steady idle, yay! everything worked great, it was running really smooth. So I decided to go drive around the neighborhood a little bit, well I got to the end of my street and the jeep suddenly died??

I let it sit for a few minutes and then it started right back up. I'm thinking that maybe the float in the carb is too high? does that sound like a possible culprit?

Anyway, I decided to try again and drove down my street, this time the same thing happed only I couldn't get it to fire back up right away, as I was cranking it, all of the sudden all power went out like the battery wasn't even in the Jeep, interior lights, nothing So a had it towed back down the street. I'm pretty sure this would be related to a short somewhere behind the dash, so today I will pull the dash out and sort through the mess of wires and try to find the problem.

I almost had it ready to for trail ride, but no..there's always something else, I was planning on re-wiring most of the stuff under the dash anway so thats not a big deal, but I'm a little concered as to why it would just die and then not start right away?

Any advice would be appreciated!!

Thanks!

 

Ahhh well it wasn't as bad as I thought...turns out the main wire harness connector came loose, I'm going to guess this is why the Jeep died also. I cleaned out the connector (full or corrosion) plugged it back in, and voila Jeep fires right up, holds a steady idle and sounds great when under throttle. Now its time to button up some of the electrical (turnsignals and break lights) and I think I have a solid Jeep except for a little chatter coming from the clutch I put in, I'll mess around with the linkage a little to see if I can fix that problem, I'm no hurry to pull the trans again unless I absolutely have too.

Thanks A LOT for all your help with this stuff!!. This site rules and without it I would be in serious trouble.

I hope to post some Lefthand trail ride pictures very soon!