Fuel line psi gauge

[66bird428]

I’m having some stuttering with acceleration and stalling. New mechanical fuel pump and filter, just changed the plugs and wires. Wanted to check psi from the fuel pump to carb, prior to opening the carb to check float level.
Question, I have stock steel fuel line to carb, is there a small psi gauge that I can screw on between the line and autolyte 4100 carb? Where some people put the small filter?

[jtschug]

This might be blasphemy, so please disregard if too offensive.

Find a good spot on the fuel line where the tube is fairly straight. Cut the line, remove a section of tube. Add a swivel nut and collar, make an AN flare in each cut end of the tube, insert a part like this:

https://www.summitracing.com/parts/ear- ... 8REALw_wcB

Screw the fuel gage into the port.

[66bird428]

Not blasphemy in the slightest.
This is the correct way to do it.
Since I’m running stock and just wanting to confirm psi during idle and higher rpm, I was looking for a ‘cheat’ way to get the info I need then remove the gauge.
Appreciate your advice!

[Rusty57]

This might be too “old school”. I just disconnect the fuel line at the carburetor and “deadhead” my combination pressure/vacuum gauge to it. I start the car and let it run on the fuel in the float bowl. That should give you a pressure reading.

As a back-up you probably should check the shop manual and follow that procedure for checking the fuel pump pressure and output.

[66bird428]

I appreciate the old school!
Just reading something, my car idles higher in park than in gear. Will drop rpm when putting in reverse to back out of my garage. Does this imply a vacuum leak? Or is this normal?

[Rusty57]

The idle speed difference is normal for automatic transmission cars. When the transmission is in park or neutral none of the clutch packs or bands are engaged. So the car is not trying to move.

When your put the transmission into gear there is load applied to the engine because the car wants to move. The torque converter is slipping and absorbing energy. This increased load reduces engine speed unless the throttle is opened more.

The mechanical analogy is that in a manual transmission car you have to increase engine speed as you engage the clutch. Otherwise the engine will stall.

If you check the specifications for your car I expect that the idle speed will be specified with the engine at operating temperature and the car in gear. There might also be a higher speed specified if the transmission is in Park.

[66bird428]

Rusty,
I really appreciate your explanations.
I like to learn.
I looked up the settings.
Resting idle should be 500 rpm while in drive.
Any way to know what resting idle should be in park?
I’d like to work solo learning this stuff. So, putting it in drive and reading the timing light rpm ain’t so easy.
Jeremy

[Rusty57]

I would set the idle speed at 700 rpm in park and see if you like the way it drives. If it tries to stall when you leave a stop or turn the steering wheel (that loads the power steering pump) increase the speed slightly.

Don't worry about that 200 rpm difference when setting the timing. It is not enough engine speed to introduce any vacuum or mechanical timing advance.