Ok heres a stupid question but I have to ask. Im going to tempt to set up my timing. I have an adjustable timing light that I will be using. No directions with this so how the heck do I go about this? Thought I would ask and same a whole lot of time. I have used a basic light for years but not an adjustable.

 

The idea is that you can rev it up to any RPM and dial back to see what the advance is at that particular RPM. Not all that mandatory in my opinion but thats because I can degree the balancer for free. That is usualy good enough for me. The cheap ones do not always read 100% accurate. Probably good for a pro mechanic that needs to diagnose a sticking advance mechanisim quickly. Still a great addition to the tool (toy) box.

-Mark.

 

The idea on setting base timing with an adjustable light is set the number to 8 or 10 or whatever on the light and then adjust the timing using the TDC marks on the pointer and balancer. Ideally you should then be able to dial the light to 0 and the marks should be at 8 or 10 or whatever you just set them for. Mine didn't recently so I took it to the MAC man. He sent it off and I got a brand new one in exchange, for only $80.

Seems like some Japanese cars have 1 mark on the balancer for TDC and a pin for a pointer so you need an adjustable light to time them.

 

Great for setting timing at full advance, like what Lars recommends. Say you want to set it at 36 degrees at full mechanical advance. Just set your light to 36, rev the motor until the mechanical advance is at the limit, and then adjust your distributor until the mark shows at 0 on your balancer. Any adjustments you need to make can be made by dialing them on the light and then matching the balancer with the 0 mark on the motor. It can be done also by scribing a mark on the balancer as mentioned above, but to me that seems like a PITA, not to mention you will have to scribe more marks if you need to adjust the timing for pinging, etc.

Here's the link to Lars' paper: http://www.corvettefaq.com/redir.asp?site=26

 

do this right the first time ....take measurements,notes and record degrees and rpm....it will let you see advance curves etc....you will get to really like that dialback feature.

 

Great thanks. Thats the info I was looking for. Saves a lot of time just ask...

 

I'm guessing that you're doing this on an '81 Vette? If it still has the computer controlling the carb & timing then timing it up is slightly different to "normal". There will be a couple of electical connectors to the distributor, one of which must be disconnected prior to timing the engine, otherwise the timing will be set wrong. I can't remember what connector it is (I never can!) but the engine will still run with it disconnected, whereas it won't if you disconnect the wrong one. I think the connector to disconnect has 3 or 4 wires on it? Once you've disconnected it then stock timing is 6*BTDC at idle but advancing it will usually improve throttle response (& power?). I set mine to 11*BTDC & there was an improvement in low speed throttle response. Don't forget to connect the connector back up when you're done!

 

Yes I am doing it on my 81. I have taken out the computer distributor and replaced it with an mallory HEI. Also I have replaced the computer carb with a non computer q jet. Why because it ran so rich that when you came to a stop or left it idle it would burn your eyes. I am still waiting for the light to get here. But here is what is going on now. Wont downshift and kick in the four barrels, lack of power. The computer is still plugged in. Do I need to unplug this? I know it will not lock up torqueconverter but does it have anything to do with the running of the car? I was reading about the detent cable adjustment and I think I have that out of wack. I will try to reset it. Shouldnt the four barrels kick in even if that is out of wack? choke is open all the way.Thanks Randy

 

The torque converter not locking won't be a problem (it'll just run at slightly higher rpms in "3" (250-300) generating a bit more heat & drinking more fuel).
Not kicking down could very well be the cable be the cable adjustment (or do you mean that it won't downshift at all?). It's easy to set up the cable adjustment. Grap the plastic sliding thing that's near the carb & slide it so that it "lengthens" the cable (I think you have to hold a tab in to slide it. Not sure as mine was so FUBAR'd that it needed a Bubba approach). Then sit in the car & floor the go pedal. The adjuster should slide to the correct setting when you do this. It's important to do it with the throttle pedal & not at the carb linkage as the pedal may not open the linkage as far as you can manually. It may be worth getting somebody to slowly push the pedal while you watch the adjuster. Mine was in a mess & didn't like to adjust itself (it wanted to bend double) so needed some help in sliding.
Computer still plugged in won't make any difference to the carb & timing as these are now done by the new carb/dist. Something that may be worth checking is the emission control stuff. Mine was all missing when I bought the car but it looks like (from what the manual says) that the computer had a big input on things like EGR, etc. If the emission controls are still in place then it's worth checking that things like the valve in the exhaust pipe just below the manifold on the p.side aren't permanently closed.
Also check that all vacuum lines are hooked up correctly (inc the one to the modulator on the trans).
Also check that the carb opens to full throttle when somebody presses the throttle to the floor. I don't know what carb you've got (& wouldn't know where to start looking if I did!) but I'd start off by looking for obvious things like bad cable adjustment, secondary lockouts, something physically stopping the secondaries from opening (snagging brackets, hitting the air filter housing, etc). If you can't find anything then it may help to post a separate question on the carb.
Good luck.

 

when you are all squared away ....we can get your Lock up hooked back up for you....however eat the elephant on bite at a time

 

I will do what you have mentioned. I did get my timing light today so now I have something to work with. Thanks alot Randy