I've been having a hesitation problem at 2000rpm on my 86 SE 2m6 for a while now, we pin pointed a fuel pressure problem. I'm currently getting about 15psi of fuel pressure at most when it should be at 35psi. We verified the lines and there is no fuel leak and obviously the pump works, the fuel filter is also brand new.. the tune up is also brand new along with a new EGR tube.

1) Is there a fuel pressure regulator and could it be the root of them problem?

2) if not, do you suggest changing the fuel pump right away or looking at other things that could be causing this problem? We are not sure where to go from here, usually when a fuel pump dies.. it just doesn't work anymore, it doesn't work at half power..

the regulator is located on top of the fuel RAIL, below the top of the intake manifold. may have dirt in it. may or may not be the problem, but thats where it is.

Your fuel pump also has a check valve in it that allows pressure to build up, then holds the back pressure. Also, the pressure regulator on your manifold is supposed to hold fuel pressure up to "about" 40/45 psi then let the excess bleed off through the return line.

To check the regulator just pinch off the return fuel line with a tool that won't cut into the line. With the line pinched off and your fuel pump running, if the pressure now builds to 40 psi or so, that might indicate the pressure regulator is shot. These can be bebuilt or replaced.

If you still can't build pressure with the return line pinched off, then the fuel pump is suspect.

Hope that helps.

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Marc in sunny Titusville, FL

• 84 SE son's car, loaded
  
• 85 Coup w/V6 transplant
  
• 85 GT newly on the road
  
• 86 SE/GT "The Chameleon" - big plans!

Do the return line test as stated above. A vise grip with hose on the jaws can work well.

It can also be a split hose inside the tank leaking fuel. That has happened to several owners on the forum.
Or a bad pulsator inside the tank.

If you block the return line you should be over 40psi easily if the pump is good.
The check valve in the pump only holds the pressure in the system when the pump is off and should not affect how much pressure the pump can produce.