scorp508

Wouldn't you expect the engine to suddently bog down hard from a big increase in fuel pressure? Puling mine seems to do nothing. Or maybe it is running so rich it doesn't make it noticeable. Neeeeeeed to figure this out. Bah!

I really need to put a FP gauge on it. I also learned that you can't just pull the screw totally out of it (its adjustable) as it makes a big vacuum leak. We figured that out when it was bleeding vaccum bigtime with a hand pump on it. It is still bleeding down a little bit with the screw in place and a hand pump on it. A very small amount (which maybe the engine can overcome), but still a very small amount.

needanother1

Yes, I would expect it to bog. But I haven't tried it.

I'm about to install mine, and I was wondering if it would hurt anything to put a little non-hardening thread sealant on there to help prevent vacuum leaks. Presumably after you get it dialed-in you don't mess with it, right?


[Modified by needanother1, 2:10 AM 10/29/2002]

sinistervette

Scorp,
I just went outside and pulled the line off mine, and it stumbled, ran like the choke was on(if it was carburated), and then I put my thumb over the vacuum line to keep it from leaking the thing almost died. Some vacuum diaphrams like these actually have a "bleed" hole that is designed to leak a little, this allows them to be a little bit more useable by needing more vacuum to make them function, and anything below that the open or close. Not sure if your is like that, but that could be why it won't build/hold with a hand pump. GO GET A FUEL PRESSURE GAUGE OUT OF YOU DADS TRUCK! :D
I got mine at Auto-Zone :U , but it does work and only cost $28.95! I just do not care for the people at our A-Z. That fuel pressure gauge will be your savior! :cheers:

mooncricket

Dang, I should've posted about this on that Autozone sucks post, but I bought the same FP gage from AZ, and the pressure relief valve went to hell a week after I bought it. It just stuck open and wouldn't free up. Then when I was trying to get it freed up the rubber seal started ripping out of it. I wound up putting a radiator petcock on it to make it usable. :smash:


[Modified by mooncricket, 12:02 AM 10/29/2002]


[Modified by mooncricket, 12:03 AM 10/29/2002]

ol,RJ

you need a fuel pressure gage (and a vaccume gage, helps to see what the motor is pulling).
I know your running a new motor, but did you change anything (like injector size, cam)? I don't recall seeing you post any info on the new motor, that could help. this rich condition could be just a matter of changing the injector constant.

LPDesRoche

On any fuel injected car I have ever owned, pulling the vacuum line off the regulator while running has not produced a change in anything. The increase in fuel is ever so slight at that pulse width the car would not/should not notice it at all. You are talking a 8-10 PSI increase at 0% throttle with a very minimal injector percentage.

Just so I am not crazy I just went out to the garage and started both the ZR1 and my 91 and pulled the vacuum lines no change.......

0ski_dwn_it

Mine doesn't change much either.....

Sounds to me like you are pulling way to much at idle.

vettmech

Mine doesn't change and the vehicles I use here at school to teach with don't either. When monitoring fuel pressure while removing the vacuum hose it increases the presure but not by much. They normally run at about 38 to 42 psi and pulling the hose will make it go up but not bog........ I have a pressure guage permanently mounted on my engine so I can watch it :seeya

SPD DMN

You can hear a slight change in the engine when I pull mine, but you better be paying attention as it is very slight. It certainly does not come close to bogging the engine though.

Scott85

You can get a rail mounted fuel pressure gauge from Lingenfelter for around $45(about a year ago). Summit or Jegs might have the same one.

Vic'89

The car will not bog down at all.

You are going from about 37/38 psi to 43/44 psi.

Vic

dlmeyers

Mr. Scorp,

Consider getting the Actron fuel pressure gauge available at your Sears store. I have a Kent-Moore and a second gauge, fluid filled, very accurate. I like the Actron better'n all of em.

The Sears Actron has the button type pressure relief valve on this particular model. You can relieve pressure quickly, get an accurate reading of fuel pressure, and perform a fuel pump volume test, all with one hand and done safely.

If you need $50, I'll loan you the money. Just you. Not everyone. Or, tell your Dad how much you appreciate his guidance over the years, how you'll always be there for holidays, and you really need the Snap On pressure gauge with the side release pressure button. A fuel pressure gauge is an ABSOLUTE must for these engines.

It's only a car, it's just physics.

dlmeyers 90 coupe zf6 3 speed shocks

scorp508

Sears has Actron eh? I'll stop and grab one on the way home. Thanks for the heads up! :D

scorp508

No sears in my area carries it, looks like a nice unit too.



Looks like pepboys or autozone, ugh.

scorp508

Autozone has this actron CP7818 unit.



Still has a pressure relief.

Bluevette85

I have the Actron and it works well :yesnod:

mooncricket

This is exactly the one that I got from Autozone, the relief valve didn't last a week as I mentioned. Also, there were two of them on the rack in the same exact package, but the gages were different inside. I remember it because I was looking at them both and trying to figure out which one to grab. :rolleyes: