[77 Canamman]

Timing spec for the '77 W72 is 16 degrees BTDC with the vacuum advance disconnected. Your problem is probably either vapor lock, or an overheated distributor module. The HEI modules need a coating of dielectric grease spread on the mating surface that mounts to the distributor body. This serves to transfer heat from the module to the distributor body. A weak pickup coil in the distributor will also cause the symtoms you describe. A quality fuel pump is essential for proper performance, and to eliminate vapor lock. The W72 fuel pump should have a large can on the bottom of it. Once it is running again, check fuel pressure, and volume.

[bobbycjr]

You're right. I'm sort of shooting in the dark without a diagram/assembly manual. Tell me where the EGR is located on this car, and I will check it out. Thank.

[bastard]

EGR valve is the UFO looking thing on the right side of the carb.

[sport coupe]

Need help from 76-77 owners. From the diagram part Number 20 is the EGR valve. If it is disconnected, need a lot of help. Taking a guess that this diagram is correct for your engine. Side note see #46, another name for it is called the heat riser. I don't have the 76-77 service manual.

[bobbycjr]

Thanks for all this info. That diagram should be a lot of help. I may post some more photos soon to try to clarify things.

[se428bandit]

If you pull the water pump check the plate in between the pump and the timing cover.I had one that had little tiny pin holes in it and it would make the car run hot.What type of mix [antifreeze/water] are you running.

[bobbycjr]

Originally Posted by 77 Canamman

Timing spec for the '77 W72 is 16 degrees BTDC with the vacuum advance disconnected. Your problem is probably either vapor lock, or an overheated distributor module. The HEI modules need a coating of dielectric grease spread on the mating surface that mounts to the distributor body. This serves to transfer heat from the module to the distributor body. A weak pickup coil in the distributor will also cause the symtoms you describe. A quality fuel pump is essential for proper performance, and to eliminate vapor lock. The W72 fuel pump should have a large can on the bottom of it. Once it is running again, check fuel pressure, and volume.

Thanks for this info. I'm thinking the distributor may be part of my problem. I'll check the fuel pump also.

[bobbycjr]

Originally Posted by sport coupe

The tree valve that is disconnected is listed as it controls the EGR and EFE thermal vacuum. Is the EGR disconnected? It would help if someone posted the emission control system vacuum diagram for the 77 400 to see how it should be connected.
Also you should get a bottom battery spacer and the battery hold down parts that are still available.

I've been looking at photos of Trans Ams and one Can Am that went off ebay today, and it seems a lot of those tree valves are either disconnected or plugged altogether.

[77 Canamman]

The car will run fine without the EFE and EGR hooked up. These systems on my car have been disabled, but with BB's, so it all appears stock. The drivabilitywas not affected, but I also jetted the carb richer, and redid the advance curve in the distributor.

Performance is much better now. Stock quarter mile times were a sleepy 16.5-17 sec. Mine has a best of 15.2@90 with a mediocre designed 2" dual exhaust system without any crossover. If I get a real exhaust and mufflers on it, I should be able to break into the high 14's.

[bobbycjr]

Originally Posted by 77 Canamman

The car will run fine without the EFE and EGR hooked up. These systems on my car have been disabled, but with BB's, so it all appears stock. The drivabilitywas not affected, but I also jetted the carb richer, and redid the advance curve in the distributor.

Performance is much better now. Stock quarter mile times were a sleepy 16.5-17 sec. Mine has a best of 15.2@90 with a mediocre designed 2" dual exhaust system without any crossover. If I get a real exhaust and mufflers on it, I should be able to break into the high 14's.

I really do appreciate all your help (and the other guys, too) with this issue. After my last failed attempt at taking a trip in the car, I felt like I needed to "back off" and take a breather. I am getting another car ready to take to the Charlotte Autofair, and then I will put some concentration back on the Can Am. Sounds like from the latest posts that I need to see what kind of fuel pump I am running, check the distributor (I've even considered putting the stock one back on), and maybe, just for good measure, remove the water pump and check it, too. Thanks again.

[Kbars CanAm]

Where does hose #48 in the diagram connect at the bottom? My Can Am did not have one so I purchased one this winter. I am wanting to get installed. Kbars

[bobbycjr]

Originally Posted by Kbars CanAm

Where does hose #48 in the diagram connect at the bottom? My Can Am did not have one so I purchased one this winter. I am wanting to get installed. Kbars

Not trying to be an expert here, but if duct #56 is the one that comes from the firewall out under the battery tray, that would be where the hose connects on the lower end.

[77 Canamman]

Bobby is correct. The lower duct #56 screws to the battery tray, and that is what the air hose connects to.

[bobbycjr]

Posting a few photos of my engine compartment taken today. I was fooling around to see if I could find anything unusual, cranking the car to see how it runs, and I found this vacuum port on the intake behind the thermostat, with gasoline vapor coming out of it, same as the carburetor was doing. It did effect the way the car runs when it is plugged. This fitting can be seen in the first photo.

[77 Canamman]

That port should be connected to the air cleaner Thermac sensor nipple which is on the underside of the air cleaner housing.

There should not be any vapor coming from this port when the engine is running. This will affect the way the engine runs because this is a relatively large manifold vacuum leak. Sounds like the carb is porking too much fuel to the engine. Is there any black smoke coming from the exhaust?

[bobbycjr]

I should have clarified that the fumes/vapor from the carb. and the port were after the car was shut off. No black smoke as far as I can tell.

[bastard]

It's normal for "fumes/vapor" to vent from a wide open vacuum leak after the engine is shut off.

[1970cat]

like was said, check your fuel pressure. sounds like its flooding. i have had a few "parts store" fuel pumps lately that have gone bad anywhere from two weeks to six months. not sure if it is inactivity of the vehicles, poor gas or what, but they showed the same symptoms as yours. also should put a clamp on that rubber fuel line if there isn't one

[77 Canamman]

Originally Posted by 1970cat

also should put a clamp on that rubber fuel line if there isn't one

That is the fuel line insulation.

[bobbycjr]

Originally Posted by 77 Canamman

That port should be connected to the air cleaner Thermac sensor nipple which is on the underside of the air cleaner housing.

There should not be any vapor coming from this port when the engine is running. This will affect the way the engine runs because this is a relatively large manifold vacuum leak. Sounds like the carb is porking too much fuel to the engine. Is there any black smoke coming from the exhaust?

A plus on the too much fuel. The guy that does my mechanic work stopped by to help me get the car running, so I could at least get it to the shop. After setting the timing, he saw the fumes rising out of the carburetor after shutting the car off, and said it was flooding. Looked inside the carburetor and it was still dripping fuel. We removed the carburetor, and he is going to check it out good. Then we will start all over again.