My70 LT1 does not like to idle below 800RPM and sometimes is a little hesitant when coming off idle. I have heard that an MSD ignition box can improve idle smoothness, starting, and takeoff. IS it worth it? Also, does anyone know if that would help reduce the rich smelling exhaust? I just had the carb rebuilt last summer, &put in a new timing chain and had it tuned so I think those bases are covered.
Thanks
Peter

 

If weather permits....I am putting in my MSD distrib, coil, and 6al box this weekend....currently running the stock one as I waited for my HEI cover for past 3 months....was back ordered...

I hope it resolves the same things to mine, better start, take off, and the rich smelling exhaust....

must admit...I am planning on returning the MSD 6al for the Digital 6 though...

 

Hi Peter, I have no problem with idle, even down to 500rpm. I really don't think you have ignition related problems in this area.

What carb are you using, the stock Holley?
The first clue to the idle problem is the rich idle. How rich ? Is it 'burn your eyes' rich ?

If someone set up your mixture screws that is used to a Qjet, then they may have set them too rich. The thread is more course on a Holley. Less turns equals more adjustment. Also, you could have a power valve going bad and leaking fuel.
You mentioned you had the carb rebuilt last summer. If they didn't use genuine Holley parts, then that could be an issue as well.
I've tried using other brands, and it just does not work.

Sounds to me like you need more work on the Holley, given that the current ignition is in good order. Points, plugs, wires, cap, rotor are good.

If you are using a 'out of the box' replacement carb, you could use a lot of carb work to get it to run well. (First hand experience)

Barry

 

The rich smell is probably coming from a rich condition from a mis-jetted or poorly adjusted carb. I had the same problem with a rebuilt Q-jet, it was not setup for my car and the car ran like crud. I replaced the carb with a correctly jetted and adjusted carb, the rich smell went away and the car ran better.
We have a couple of guys that hang out here on the forum, Tom454 and Lars. Both of these guys can tune and adjust your carb to factory specs, they both do top work and are well respected by everyone here on the forum. Contact either of these guys and ask them their opinions. Look at the post at the top of the forum list and you'll find that Lars has a "loaner program" he'll send you a loaner carb, and you send him yours for setup. He is very reasonable in his prices.
I also had problems with the car's idle, it was ignition related. I swapped my points out for a Pertronix electronic ignition and it improved a great deal. A few weeks ago I pulled my distributor and found that it wasn't points that were causing the poor running. The Pertronix had masked the problems that my distributor had. The main shaft and lower bushing were very worn, I had about .080 up and down end play on the shaft also. I rebuilt the distributor, with a new lower bushing and shaft, reshimmed the bottom gear for end play. I also installed a recurve kit that I bought from Lars for $40.00, I expect that my car will perform ten times better when I get it back together.
Sorry to get sidetracked, but yes the MSD will probably help your idle, but check out the condition of your distributor and make sure it is good shape, before you add the MSD. You can rebuild your distributor cheaper than adding a MSD6.
Good Luck!

 

I put complete MSD system on my 427 , the mech tach drive dist, coil, wires & box, approx 5 years ago,= instantanious starting, smooooth idle, no missfire....actually have not touched ignition system since...... worked for me :seeya :chevy :flag

 

ignition upgrade is always good and while it will help you it will not cure your original problem which as most of the guys here stated is an out of adjustment carb problem :yesnod: :cheers: :cool: