Fuel pressure regulator help
Thread Starter
Racer
Joined: Feb 2005
Posts: 338
Likes: 49
From: Quincy,Illinois
Fuel pressure regulator help
Since I have the intake off of my 86 to fix a coolant leak, I was going to replace the FPR so I wouldn't have to take it back apart again soon. Most parts stores offer a replacement diaphram instead of a whole new regulator. Has anybody had good luck taking their regulator apart and replacing the diaphram or should I try to find the whole unit?
Also since I have removed all of the AIR and EGR from the car, I will be removing the EGR valve since I have access to it now. What does the vacuum line do that is connected to the FPR. Is it just to draw off any gas that leaks if the diaphram get a hole in it or does it have something to do with the function of the FPR. I am removing the EGR vacuum solenoid that is attached to the thermostat housing bolt and the vacuum hose that connects from there to the FPR. I was just going to hook up a vacuum line from the port at the pass. side rear of the plenum. Will this work? Thanks.
Also since I have removed all of the AIR and EGR from the car, I will be removing the EGR valve since I have access to it now. What does the vacuum line do that is connected to the FPR. Is it just to draw off any gas that leaks if the diaphram get a hole in it or does it have something to do with the function of the FPR. I am removing the EGR vacuum solenoid that is attached to the thermostat housing bolt and the vacuum hose that connects from there to the FPR. I was just going to hook up a vacuum line from the port at the pass. side rear of the plenum. Will this work? Thanks.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
The diaphram is the heart of the unit. It is not difficult to replace since you have everything else off. You will need a speical torx bit that has a center post to remove the top of the regulator screws Check your unit to be sure this tool is needed.
Just be carefull when you install the diaphram, do not overtighten the screws. If you do it will tear the diaphram.
Just be carefull when you install the diaphram, do not overtighten the screws. If you do it will tear the diaphram.
Drifting
Joined: Oct 2006
Posts: 1,934
Likes: 3
From: Citrus Heights California
The diaphram is the heart of the unit. It is not difficult to replace since you have everything else off. You will need a speical torx bit that has a center post to remove the top of the regulator screws Check your unit to be sure this tool is needed.
Just be carefull when you install the diaphram, do not overtighten the screws. If you do it will tear the diaphram.
Just be carefull when you install the diaphram, do not overtighten the screws. If you do it will tear the diaphram.
Just buy a diaphragm. It takes about 10 minutes to rebuild a fuel pressure regulator. My fuel pressure vacuum line is connected to the plenum. I'm not sure but I believe the vacuum line helps regulate the fuel pressure.
Last edited by Kool88vette; May 10, 2008 at 11:51 PM.
Thread Starter
Racer
Joined: Feb 2005
Posts: 338
Likes: 49
From: Quincy,Illinois
Thanks Kool88. Is your vacuum line connected to the ports at the rear of the plenum on the pass side. if the vacuum helps the FPR, what happens when the vacuum drops of when the throttle is opened up?
Drifting
Joined: Oct 2006
Posts: 1,934
Likes: 3
From: Citrus Heights California
I copied this from a tech article:
The vacuum connection is there to help reduce emissions during deceleration. During deceleration, the vacuum connection serves to open the fuel return valve wider, which reduces pressure in the system and prevents excess hydrocarbon emissions due to less fuel being injected as a result of the lower pressure in the system.
This is a very nicely designed device in that it provides for an automatic self-adjusting pressure regulator and emissions control device all rolled into one. The simplicity of the design also contributes to its reliability; the fuel pressure regulator rarely, if ever, goes bad. There's just not much to go wrong with it.
Last edited by Kool88vette; May 11, 2008 at 03:42 PM.
