I was attempting to dial in the timing lastnight. When I first started the engine to warm it up, it fired right away (normally does). I shut it off and then attempted to start it again. It was turning over, but not firing. Pulled the #1 plug and kept it attached to the plug wire to see if it was sparking; no spark. I tried it again and had spark. :confused: The Mallory HEI distributor is only 4 months old. I can't imagine the coil is bad already. Any suggestions?

2nd issue. Popping/backfire through my carb. It's a Holley 750 DP. It backfires when the car is ideling or at low rpms and I then give it gas. Sometimes it dies other times it recovers. I also have black smoke/carbon blowing out the drivers-side exhaust. Suggestions are welcome. :confused:

Thanks,
Kevin

Sounds like you retarded it too much. Depending on the setup of your motor. Anywhere from 4*btdc and 10*btdc should be about right. Recheck your timing. Be sure that your vacuume line to the dist is disconnected and plugged.

Just a quick suggestion -

Whenever I wonder if a wire / plug is firing - I just hook up my timing light to the wire - if light fires, juice is flowing to that one.

Also - it is easier to see the light flash from inside the car (I'm getting old...)

I hate having a wire / plug loose arcing -

Steve

Dobek,

I had the timing light hooked up to #1. It didn't flash when I tried starting the car. I thought (or was hoping) something was wrong with my light. That's why I pulled the plug to see if it was sparking. Thanks.

Nantooch, I have to admit, I'm not the most savvy when it comes to tweeking. If I retard the timing a bit and the RPM's go down, do I adjust the idle screw to bring it back to the proper RPM's. Also, should I adjust the fuel/ air mixture at all. Right now they are three turns out each. I guess I'm not sure which order to start tweeking. Adjust fuel/air, then retard timing, then idle screw? Or does the fuel/air mix not even come into play? Please correct me if I'm way off. I don't want to damage anything. THANKS!!!

Kevin - My experiences have been most holleys dial in around 3/4 to 1 turn on the idle mixture screws. Set them to 1 1/2 turns, fire the engine up and when it's warmed up to operating temp set the idle to anything under 900 rpm and check your timing with the vacuum advance disconnected and the source plugged. Set the initial to somewhere between 4 and 12 degs btdc. If you are at 4 and advance it to 8 the idle will increase so adjust the idle screw back down below 900. Leave the vacuum disconnected and take a test drive and listen for WOT pinging. If you have to retard the timing to get it to 12 degs the idle will drop some so adjust it back to where you had it.

Find the most initial timing under 900 rpm you can (12 - 14 degs maybe) without causing WOT pinging and then set your idle to where you actually want it for final tune. Now put a vacuum gauge on a manifold source and and lean out the idle mixture screws until you make the most vacuum. If you don't have a gauge, lean it until it starts to stumble, then back it out until it smooths out. Adjust the mixture screws slowly and keep both the same. This may have messed with the idle so re-adjust as necessary.

The last thing to deal with is hooking the vacuum advance back up. Depending on how much vacuum advance is brought into the game you may have some part throttle pinging with it hooked up. Before making other adjustments try the vacuum advance on a ported source (no vacuum at idle) If no part throttle pinging your good to go. If there is part throttle pinging then switch it to a manifold source (vacuum at idle) this will raise your idle and the amount of timing you will read. Adjust the idle back down and take a timing reading. What you are seeing is initial (say 12 degs btdc) plus vacuum (might be 20 degs) so you might see as much as 32 degs btdc. Don't panic, the vacuum goes away when you go WOT and the engine sees only the initial when starting. Now test drive for part throttle pinging and if present retard the timing by 2 deg increments and test drive.

If you end up taking all the initial away to get rid of part throttle pinging you need to replace the vacuum canister with one that doesn't make as much advance. The adjustable work real cool... if you end up replacing the vacuum canister set the initial back per above and adjust to get rid of part throttle pinging again...

Kinda long, hope it helps.

Dennis,

Thanks for the information. I didn't care how long the explanation was. It was very helpful. That's all that matters to me. I just want to get the car running like it should.

Thanks,
Kevin

graemlins/thumbsup.gif

Looks like scholar Dennis answered most eloquently on it. Go with his advice. I kept it for myself too. graemlins/thumbsup.gif Dennis

Dennis,

This will sound stupid, but what does WOT stand for? I'm going to attempt your suggestions this weekend.

Thanks

;)

Wide Open Throttle