New problem

[nlreb54]

As I set the timing engine runs smooth as long as the vacume hose is disconnected from the distributor. As soon as it is reconnected or I place it in drive the engine runs rough and surges. Timing is set at 8 degrees. Idle is set at 700 in drive. I have around 21 HG in vacume pressure. All hoses have been checked and also all plug wires. Anyone have any suggestions?

 

[GTR1999]

Sounds like you have a vacuum leak which can be a bugger to find sometimes. You'll have to start working your way from the vacuum source to see if you can isolate it and fix it. Look at the headlight vac cans or relays.

 

[vette-dude]

It might be the diaphram in your Vacuum Advance cannister on the Dist. Easy check is to take off Dist Cap, disconnect hose and blow smoke through it. If the smoke comes out of the distributor the diaphram has failed. For non-smokers you can use a might-vac and pull a vacuum on the cannister and see if it holds.

Randy

 

[GerryLP]

As I set the timing engine runs smooth as long as the vacume hose is disconnected from the distributor. As soon as it is reconnected or I place it in drive the engine runs rough and surges. Timing is set at 8 degrees. Idle is set at 700 in drive. I have around 21 HG in vacume pressure. All hoses have been checked and also all plug wires. Anyone have any suggestions?

Nireb,

When you disconnected the vacume hose at the distributor -did you plug the carb-side of the hose? If the hose is not plugged, then your carb will sense a relatively larger drop in pressure accross the venturi, and this will add-on metered fuel, so the RPM will go up and the timing would be set wrong (or at least not where you wanted it). Your timing light is indicating 8 deg BTDC at that time, for that's where you set it when the carb-side of the hose was not plugged. Therefore, when you plug the vacume hose again, the signal that the ventury was getting is eliminated, and the rpm drops, and it is probably just as if you were setting the timing at maybe 4 deg BTDC? Maybe?

The bad news is that if this is what happened, then you'll have to start all over with the timing, and then the idle, and so on, but the good news is that it should not be alot of adjustment and its a learning experience.

If this is not the case, then look at what Vette-Dude said. For a stock vacume canister, the were set at the factory, and no adjustment was available. The good news is that you can purchase an adjustable one that will work, but the bad news is that you'll have to attach the timing light and set the vacume advance.

 

[vette-dude]

Did you find the problem yet??:confused


Randy