CAV GT40 Vacuum pump

I have CAV # 170 and am trying to trace down problems with the electric circuits. One circuit is labeled vacuum pump, but can't find one anywhere, electric or other wise. Is there one? Thank you
 

Pat

Supporter
I have one listed on my schematic but it isn't hooked up. I'm not expert but I think the electrical vacuum pump is for vehicles using engine combinations that provide little or no manifold vacuum required for braking. Since my brakes take manifold vacuum, the circuit is not needed in my installation.

I'm not sure what type of electric issues you're having but I would check your fuses and make sure they aren't the Chinese junk variety. I replaced mine after a discussion with the guy at NAPA. I also went to a 100amp alternator and my issues with the starter went away.

When I first got the car, the left side lights were blowing fuses and it turned out to be the license plate light assembly shorting out.

If you want to describe the problem, maybe some of the folks here could help.
 
Thanks for the info.
A mechanic is working on tracing down the circuits. But some of the indicators were harzard lights not working, turn signals not working, speedometer ran intermitently, horn didn't work, fuel pumps were running, but no fuel pressure, (had just filled tanks), causing the engine to suddenly die and hard to restart. Many of the fuses were much higher than called for in the schematic.
The diagrams on the fuse box cover were not consistent with the diagrams in the owner's manual.

I purchased an owner's manual ($78.00!!) from Johann at CAV in Raleigh, but he said he couldn't guarantee that it would apply to my car due to significant changes in the design since # 170 was shipped.

Is there any way to get an accurate schematic?

Any insight on this would be appreciated.
 

Pat

Supporter
Hmmm, not to disagree with Johann but #170 is a pretty recent car. If you shoot me a PM with an email address, I'll send what schematics I have. I know I have pre-100 and early Autofutura ones that are probably pretty close.

One thing you may wish to check is to be sure you have a fuel tank vent. If your tank can't breathe, you'll get some symptoms like you describe. You may also want to check your fuel strainers on the pumps and the pressure regulator settings.

If the car is getting hot and you are having fuel pressure issues, you may be getting vapor lock from the ethanol in your gas. Some stabilizer additive and phenolic blocks under the carbs may help that.
 
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