Sorry to be Redundent - Help

[Zed Head]

The fuel pump provides the pressure and the fuel pressure regulator (FPR) controls it, by bleeding off excess. You want to measure between the filter and rail so that you read the pressure that is in the rail at the injectors. Since the FPR is in the middle of the rail the only place to connect the gauge is between the filter and the rail.

The pressure is not directly dependent on load but the FPR does adjust pressure based on intake manifold pressure. That's what the vacuum hose to the FPR is for. When you first measure the pressure, pull the hose off of the FPR. The engine will run rich but the reading you get will be the baseline reading. It should be about 36-38 psi. Reconnect the hose to the FPR and go for a drive. The fuel pressure should vary between ~28 psi on the low end (it could go a little lower or a little higher but it should definitely be lower than 36-38 psi). When you hit the throttle the pressure will increase as intake manifold pressure increases (vacuum level drops).

When your problem happens you will probably see the pressure drop down to the low 20s or less, if the fuel pump or fuel intake is the problem. Fuel starvation.

[FastWoman]

What Zed said! However, just to clarify, when he says to pull the hose off the FPR, he means the little vacuum hose on top, not one of the fuel hoses. The spec pressure is something like 36.3 psi, but your gauge might not be dead-on accurate, especially if you bought a cheapo gauge like I did. (Mine actually cross-checks with other gauges I have, though.) Also it's interesting that he mentioned the low 20's or less, as that's approx. the point my engine would run noticeably badly when my fuel pump was fading.

[bhermes]

Guys, just wanted to let you know that I have started reading the EFI Bible (which I should have done a long time ago). One of the hardest parts of being a new guy is just understanding what and where the parts are. I am getting a much better feel for things but have a long way to go. Thanks for all the help.

I would recommend anyone with a Z and little to basic knowledge read the thing before doing anything else.

Obviously I only know enough to be dangerous but one day.

Thanks to all helping me along my journey.

Hope to get time to do all the things mentioned very soon. Waiting for a few parts to arrive that I ordered online.

[siteunseen]

In every job that must be done

There is an element of fun

You find the fun and snap

The job's a game

In every task you undertake

Becomes a piece of cake

A lark, a spree

It's very clear to see

That a spoonful of sugar

Helps the medicine go down

The medicine go down

Medicine go down

[Captain Obvious]

injector problems

an ultimate frustration

efi bible

[siteunseen]

injector problems

an ultimate frustration

efi bible

A pefect Haiku!

[Captain Obvious]

Haha! First one ever. Your prose inspired me!

[FastWoman]

That's funny!

Edited November 27, 2013 by FastWoman

[bhermes]

OK. I am a math and engineering teacher. Never read a book in my life. And when it comes to poetry?

Engine still not running perfectly.

However, thanks to this forum I now know what a perfect haiku looks like.

Thanks so much. And thanks to this forum;

injector problems

an ultimate frustration

thanks to all for this forum

[bhermes]

Was hoping to be reading a pressure gauge today; however, I got the 1/4" to 1/4" nipples and will need to replace with 1/4" to 5/16" that hardware store does not keep in stock. Will check around but found on internet. I have the tee, the EFI hose, gauge and clips.

One thing and maybe this is a dumb question or comment but I have read alot about fuel pump and fuel pump prime. Is it possible that I am loosing prime or not completely primed? Remember I did drive 100 miles and the car has been starting ok. I guess the fuel gauge will determine.

[siteunseen]

The pressure gauge will tell if your injectors of fuel pressure regulator are allowing fuel to pass through losing the "prime" or the psi it needs to crank. When you shut the motor off the gauge should hold at least 20 psi. Do you have an Advance Auto or O'reilly's around? The ones around here have all the fittings to make the gauge work, I didn't get them from a hardware store.

[bhermes]

Yep. Both. I will get them tomorrow and hook up gauge. My first step will be to just get the pressure without load. I will then purchase the 40-50 dollars worth of EFI line to run to wipers or can I get by temporarily with cheaper tubing?

Also, on the threaded pieces do I need to use anything on the threads? Tape?

Thanks.