Arny73

K, so I decided to try and fix my timing problem myself. 454 was doggie and would backfire when I would try and take off from a stop. So.... After reading many post on here I got brave. I was thinking it was to advanced. So I decided to back it off a little ( no timing light, just doing it by ear).
Well... As I backed off the dist. a little the idle started to climb! Is this suppose to do this?

I took it for a little spin and came back it still did a little backfire!! So I backed off the dist. a little more, again the idle climbed more. I adjusted the idle and took it for another spin. No backfire and it responded better.

Came back and backed the dist. A little more, again idle climbed (I readjusted it) and took it for another spin. Didn't seen to see or hear a change in response.

So... Have I done this correctly?

Are the things I have explained normal?

marz

Sounds like you got it right. I always do it by ear. Advance it until it starts to want to die and then start backing it up. It may have been way advanced on you. You probably need to get a timing light and see exactly where you have it now that it is running good for future reference.

Good job.

MelWff

buy a timing light and do it the correct way and if it is a points distributor you have to adjust the dwell first

hugie82

I think your timing was to far retarded! If you weren't experienceing pinging and hard starting. Viewing from above The dizzy gets turned counter clockwise to advance the timing

scottyp99

So, which way were you turning the distributor when you were adjusting it. Were you actually retarding it, or actually advancing it? Enquiring minds want to know!

On the one hand, it's a good idea to adjust the timing to where the engine runs best, but on the other hand, it's also a good idea to be able to record what the timing is, so you need a timing light. The best timing at idle may not coincide with the best timing at higher rpms, and modifications to the advance curve may be in order. The only way to be sure is to record the timing with a timing light. Here is a link to a thread that has a lot of info on timing:

http://forums.corvetteforum.com/c3-t...long-post.html

Let us know how things go, OK? And good luck!

Scott

Arny73

I was turning it counter clockwise

Mike Ward

Backfiring through the carb is rarely caused by timing errors. Look elsewhere.

scottyp99

So you were actually advancing the timing. Makes sense, now. Keep advancing it a teensy-weensy bit at a time until it starts to lose rpm at idle, or you experience detonation at WFOT, or lugging the engine going up hill, then back off a little bit. Best bet would be to invest in a timing light and a vacuum guage. Disconnect the vacuum advance, put the timing light on it, and see what rpm the advance stops at. Don't go more than 3000 rpm in neutral, if it's not done advancing by then, you need a recurve kit (less than 10 bucks) The kit will include lighter springs that will let your advance come in sooner, shoot for about 2500-2800 rpm. Then you'll need to determine which vacuum advance canister is right for your engine, and adjust idle mixture screws for highest vacuum. It should purr like a kitten after that.

Scott

Arny73

Will do that Scott, thanks

marz

Keep it simple Arny. Get a timing light or borrow one and find out what it is finally set to and leave it alone. If it is running right now don't mess with it. Obviously it was way off and you did the right thing now sit back and enjoy it.

scottyp99

Why even bother getting a timing light, then? it runs fine, leave it alone.

I have to say, I disagree. Tune the engine, there could be plenty of power and fuel mileage left on the table.

Scott