77' 280 acceleration problem

[FastWoman]

That one looks fine. However, the approach I took was to have my T vertical, with respect to the ground (so that it would be oriented like the letter "T"). The bottom leg of the "T" connects to the fuel filter via a very short length of hose. The gauge points away from the engine on one of the two top legs of the "T", and a hose goes from the other top leg to the fuel rail. The gauge is then supported via the hoses and faces upwards. The path of the hoses forms a 90 deg angle, rather than the 90 deg bend that it would take if just a single hose were used.

EDIT: Be careful fitting high pressure 8 mm fuel lines on 3/8 barbs! They can eventually split! I wouldn't go any larger than a 5/16" barb/nipple.

Edited June 10, 2011 by FastWoman

[brento_1488]

wierd. so my buddy had a fuel pressure guage. just popped that bitch on. it idles a just a little shy of 30psi. what im wondering now is why does it stay at 30psi when i pinch the return line? pretty sure it should shoot the psi up right?

[cozye]

what psi is it at when you rev it to 3000 rpm ?

[cozye]

also, pull the vacuum line off the FPR (and clamp it) at idle and report back what the fuel pressure is when you do that as well.

[brento_1488]

so i think this guage is bunk.. nuthing happend when i pinched the FPR hose, and it didnt move when it was at 3000 rpm. so RIGHT NOW im ordering the fp guage and T fitting...

[cozye]

I wouldn't necessarily believe that the fuel pressure gauge is bad.

If memory serves me correctly, you should pretty much get a consistent fuel pressure of around 30-32 psi under all conditions, except when cranking (which could be simulated by removing the vacuum line from the FPR). The fuel pressure should go up to about 36psi with no vacuum applied to the FPR. The fuel pressure will go down a small amount with more vacuum (20+), but not by a lot. Maybe 28 psi or so ?

If your fuel pressure isn't jumping up to 36 with the vacuum removed from the FPR, the FPR could be leaking some fuel by. If your car is still getting approx 30 psi of fuel pressure at 3000 or 4000 rpm, then you probably don't have a significant fuel pressure issue.

You will also want a vacuum gauge. You will need to report your vacuum at idle.

[brento_1488]

yey guage came today. dead it sits at 26psi, idle 30-31psi, and 3-4k 30psi.

ill post a video in a bit

[cozye]

what psi is it when you pull the vacuum line off the FPR?

[cozye]

and do you have a vacuum gauge?

Pull the plugs and post pics of all 6.

[brento_1488]

like compression test?

[brento_1488]

i did all 6 when i first got the car, they were all 126-130 i believe

[brento_1488]