I’ve got a kit car that was built by Excalibur motors in 1964. Its got a Shelby Cobra (AC) body built on a Mustang frame. The engine is a small block 302 (5.0 HO). My problem is that occationally when I start the car and begin to drive down the road, it feels like there is a governor on the engine since it will not gain speed over a low m.p.h. When this happens I pull over to the side of the road, turn off the engine and restart which fixes whatever problem took place and I can gain speed normally. This lack of power in the engine only happens about 1 in 4 starts and since the car “sits,” around in my garage alot, meaning I don’t drive it more than 2-3 times a month, I wonder if the problem is due to that?
Yeah, a car like that can really benefit from being driven about once a week, if it’s a low usage vehicle. Same goes for any older carb’d car.
You said 5.0 HO. Is it fuel injected?
There’s no such thing as a 1964 Ford 302 CID engine. Ford didn’t introduce the 302 until 1968. So what year is the engine?
@Tester–good catch. This is as good as Vinny’s girl friend, the out of work hair dresser in the movie “My Cousin Vinny”. Vinny’s girl friend had worked in her father’s garage and was put on the witness stand to testify about automobiles. The prosecution asked her about the timing setting for a 1955 Chevrolet Bel Air with a 327 V-8 engine and a 4 barrel carburetor. She correctly said that this was a trick question–Chevrolet didn’t introduce the 327 until 1962 and the engine wasn’t available with a 4 barrel until 1964.
Could be a stuck needle valve or float.
If the old fuel lines have deteriorated and become porous vacuum can pull air into the fuel line and act similar to a vapor lock and the problem can be sporadic. Also, many Motorcraft carburetors had fine wire mesh screens at the needle valve that can collect rusty scale and cause some outrageous intermittent problems such as yours.
I would also suggest that there might be rust in the gasoline tank that gets drawn up into the fuel line. My son had this problem with a Ford pickup truck that had been sitting for about a year that he purchased.
What he has is 1964 repop of a Cobra. It could be carb or FI motor. They bulit both ways. Gas tank should be Alum or plastic (ie fuel cell). I have not seen one with out a elc fuel pump. My guess is fuel fillter first. Then pump. Then we need to know if its carb or FI.
You really need to give more info about the drive train. What year is the motor? What year is the transmission? How much if any computer controls are there on the motor and transmission? If the motor is circa 2000 or later you could be going into “limp mode”.
This is much newer, the info I can find has Excalibur making these in the '90s, so it’s probably an EFI engine. It’s a tube frame with a Cobra body, nothing in common with a Mustang.
Here’s an example:
And here’s more info about Excalibur:
I thought that name sounded familliar, they made old car look-alikes in the 70s.
The nomenclature is quite confusing. Is the engine an actual Ford factory product?
I think the OP is BSing us. Ford never had a 302 in 1964. And the Mustang has never had a frame. It’s a uni-body contruction.
I immagine the kit was a 1964 cobra…
BUT many 80’ish mustang running chassis were used for many kit cars.
We need to know what year was the mustang running chassis.
“Its got a Shelby Cobra (AC) body built on a Mustang frame. The engine is a small block 302 (5.0 HO).”
Mustangs did not have “frames”, they are unibody construction. Using the belly-pan for the foundation of a kit car would be VERY difficult…Much of the running gear could be Mustang or Mustang II (Pinto) but the frame is most likely welded up from steel tube…
@Caddyman - exactly right. All the Cobra look-alikes I know of are built on a tube chassis, ranging from simple:
To complex (Factory Five, a major maker of these):