When I start my cougar the idle rpm and oil pressure seem to jump way to high. Rmp hits between 2000 and 3000 and oil pressure just slaps the right side of the gage.
Shifting into reverse or drive seems to help, but the car seems to lunge when I let off the brakes.
The carburetor is new, so im thinking maybe thats a part of the issue.
I think that’s normal. Maybe you never noticed that a cold engine has higher oil pressure than a warm one.
Your carb choke fast idle cam speed is set too high. It should be set to more like 1500-1800 RPM. But I agree oil pressure that high at 3000 RPM on a cold start is normal.
Although you didn’t mention year, engine or carburetor - and assuming this is due to the choke fast idle setting - 2000rpm is a bit high and 3000rpm is way too high.
A more typical fast idle rpm is somewhere around 1500-1900 rpm (just enough to keep the engine running while cold). That is adjustable to your liking but depending on carb can be a pain to get to.
And Royce is correct, higher oil pressure when cold is expected.
However, very high oil pressure is not. As an example, I once had a new Melling oil pump where the internal over-pressure bypass piston/spring was seized. Pegged the oil pressure meter (>100psi) and blew the oil filter seal - besides the terrific mess it made had to remove the freshly rebuilt engine to fix the pump, not a fun day…
Its a 1970 cougar with an edelbrock 650 on a 351C. Ill mess with the idle screw and mixture to see if I can dial it in to a more appropriate range.
Good to know those jumps are pretty typical depending.
I also have a 70 351C, so will be interested to hear how you like the carb once you get it dialed in.
This is not a mixture screw and idle speed screw problem. It is an adjustment to the choke mechanism. Refer to the instructions on your carb.
The adjustment that Bill refers to is the fast idle adjustment screw. Normally on Holley carburetors it is accessed by removing the carburetor and turning it upside down.
Yes, that is the one I suggested needed set for 1500-1800 RPM.
That’s it, the best way to get at it is to remove the carburetor from the engine and turn it over. .
From original poster:
1970 cougar with an edelbrock 650 on a 351C
Those are way easier to access, should be no need to pull the carb.
Got everything dialed in. Everything looks great RPM wise now. I absolutely just wasnt letting things warm up oil pressure wise. Thanks again for all the help. Drove her up to work today.
That makes me happy! thanks!
Great lookin’ ride
