68 400 with 200-4R trans, 670 Holley Street Avenger, performer intake, no AC. , power disc brakes.
I have been able to successfully start my freshly built engine and its sounds sweet. Now I have to tune it and set the shift points in my 200-4R. Thus far I have set the timing at 11-12 deg with a timing light and the dist vac plugged. I reconnected the dist vac and now two things going on: 1) During idle it wants to stall until it reaches operating temp, about 190 deg. After it is at temp it idles at about 900 RPM. 2) After it is warm I put it into gear (reverse or drive) and the RPM’s immediately go down to about 450 and it wants to stall.
The problem is, I can not drive it until I record the pressure of the transmission in each gear and review it with the trans manufacturer, to ensure I don’t burn it up. But I can’t do that because it won’t stay running. So I can’t drive it to properly tune it.
What do you think? Someone suggested vacuum leak. I have re torqued all of the carb and intake bolts and have replaced the PCV grommet. I am not using the thermo valve at all. I get all my vacuum from the carb. There is no vacuum at the trans, it is entirely mechanically controlled with the TV cable. Someone told me to squirt starter fluid around the intake and carb and if/when it gets sucked in you will know by the increase RPM and you can pin point the leak. That doesn’t sound very safe! Any other suggestions on locating a potential leak?
I also have a fairly severe oil leak. It looks like it is coming form the dreaded rear main seal. I haven’t pulled of the flywheel guard to verify.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Thus far I have set the timing at 11-12 deg with a timing light and the dist vac plugged. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Sounds like a good starting point.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> 1) During idle it wants to stall until it reaches operating temp, about 190 deg. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Is the electric choke hooked up and are you setting the choke by depressing the accelerator once before starting the engine? You may need to adjust the fast idle cam to increase the idle speed during warmup. It is part of the choke mechanism located on the passenger side of the carb. There is a screw that rides on the fast idle cam and holds the throttle plates open. As the choke heats up, the cam slowly backs off, closing the throttle plates. The screw is hard to see - the screw head is underneath the choke mechanism.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> After it is at temp it idles at about 900 RPM. 2) After it is warm I put it into gear (reverse or drive) and the RPM’s immediately go down to about 450 and it wants to stall. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I set mine to idle at about 800 RPM in gear. In neutral the idle is higher, around 1000 RPM. You may also need to adjust the idle mixture. When the engine is warm, adjust each of the idle mixture screws for maximum idle speed, and readjust the idle speed back down if needed.
Sounds like your timing is changing when you put the car in gear, either from your mechanical advance starting too early (shouldn't start until about 1500 rpm), or because the vacuum advance is hooked to a manifold source instead of a ported source. You didn't say whether you set the idle speed with the vacuum advance connected or disconnected, and whether you have it hooked to a ported vacuum source or manifold vacuum source. Unplug the vacuum advance, set the idle speed and check the timing in neutral, then in gear (warmed up of course - set the choke and fast idle after getting this figured out). If there is no change in timing and the car now has a reasonable idle, you're good on the mechanical advance. If not, put heavier springs in until the timing doesn't change. Next, plug in the vacuum advance, If you get a noticable increase in idle speed, you probably have it hooked to manifold vacuum. Find the ported vacuum tube on the carb and try that.
