need to adjust the fuel pressure (was 34 psi at the fuel rail) but don't have a meter should i try it without one and if so what should i look. for engine idle is high (1800rpm) and car tops out at 4000 rpm when driving .is this the fix? already changed cht sensor and vacuum hoses

I just built my own for 20 bucks. Go to home depot, buy one of the water pressure guages they sell that you can screw onto faucets and such. Next, walk down the aisle and get a couple brass reduction fittings that will screw in and you end up with a nipple the size of fuel line.

Go to auto parts store and buy some fuel line and clamps that will fit onto that nipple on the drivers side. Get enough fuel line so you can rest the guage on the rear lid. Clamp everything thing down and make sure all fittings are wicked tight and sealed. Maybe put some of that tape on the threads. You cant have any leaking gas.


unscrew the plug on the drive side fuel rail and clamp down the fuel line on there. Do this when the car is cold so theres no pressure in the system.

Fire her up and see what the guage says. regulator is right there so once you have the guarge working well its pretty easy to adjust.

Do not drive around with the gauge on...not designed for gas, too dangerous.

Which fuel system do you have? Carbs (better not be with 30+ PSI of fuel pressure!), D-jetronic FI (stock 1.7, 2.0), L-jetronic FI (stock 1.8) or other?

You need a gauge to set the fuel pressure. Period--you can't set it right without one!!

High idle is usually caused by air leaks. Less often, it is caused by overly-advanced timing.

--DD

Right tools for the right job....

Um.. that same auto parts store typically sells high pressure fuel gauges for under $20.

Just buy one. Then sell it to someone here on the board when you are done.


B

My car came with a fuel gauge permanently attached. Is it harmful to leave a gauge connected all the time?

Not if it's designed for fuel.

mine didn't, that's why i built my own....

Here's what I built. $3.99 for the gauge, plus shipping. It's brand new, in its original box. With the big face and 60 psi range, it gives great resolution. The company that made it was bought out in 1964, so it's old. I got two to have a backup, and took one apart- very heavy duty all brass construction. No plastic anywhere! Ashcroft made gauges for industrial boilers and the like, so it's unlikely you can even find this quality anymore. Another indicator of its age- the face plate is real glass!!

I got a few fittings at the local NAPA, and attached a leftover piece of 7 x 13 mm fuel line, and I'm rollin'.

He still has 58 of these left. eBay item number 4377179819. Check it out!

Also, I learned something- first, my pressure was set at 35 psi, and it's D-jet. And then, after shutting it off for about a half hour, it was still reading 23 psi. I've never heard any reference to a checkvalve in the fuel pump, but there must be one.... I reset the pressure to just under 30, and it's running better than it has in the 23 years that I've owned it.... Used to smell like a diesel when it idled, not any more. And I gained an inch in idle vacuum besides! Under $10 for that extra inch! What a deal!

(32 psi in the photo was with the engine off, and it was slowly on its way down)
Click to view attachment

Rich - If you buy one from a local shop I'll pay for half b/c I need to check my pressure too (never done it). Before I start mucking about w/the MPS I need to make sure the pressure is set right. It's the only thing left on my list before I start "dialing in" my MPS.

-pt

IME, most of the times I've found the fuel pressure to be wrong, somebody's dicked with it. I've never seen a bad D-jet fuel pressure regulator. And everybodys advice is correct, you can't set the pressure without a gauge. The Cap'n

I'm sure that's the case with mine. The PE did some things to "improve" performance, he told me. Like unplugging the heat sensor in the airbox, changing the value of the external resistor on the head temp sensor, etc. When I got the car, it was fouling plugs every 500 miles, so I now suspect that he "adjusted" the pressure regulator and that was the major issue. I wish I'd checked it years ago, but for want of a meter...... Oh well, it's finally set right.

My gauge arrived today. Nice find!