Problems adjusting Fuel Pressure

Rebel79 · 09-26-2001, 11:54 AM

This weekend I tried adjusting my fuel pressure on my Kirban Adjustable Fuel Pressure Regulator. I took the vacuum line off and the FP was set to 48. I can turn the adjustment screw 5 full counter-clockwise rotations and it won't drop a psi. However I can adjust it back to where it was, and turn it 3 times to the right which makes it tight, and the FP goes up to 50psi!

You see my FP was set at 38psi, but then I upgraded my fuel pump and it jumped up to 48! Its way too high and I need to lower it.

------------------
1994 Mustang Cobra
308ci, Vortech S-trim 11#, ported GT-40 heads, E-303 cam, FMS 1 5/8 headers, BBK Offroad H-pipe, 2-chamber flows, and several other goodies.
Rebel Racing. Home of Bay Area Mustangs

Rebel79 · 09-26-2001, 09:38 PM

ANYONE?

PKRWUD · 09-27-2001, 04:04 AM

Was this with the engine running?

Take care
~Chris

------------------
Retired Moderator
MustangNet

My site: JimPorterRacing

RACECAR spelled backwards is RACECAR

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Rebel79 · 09-27-2001, 09:35 AM

Chris,

I certainly hope that was a joke.

I tried ajusting the fuel pressure with the vacuum on, no change. I'm going to call Kirban to see what they have to say. I have only heard of two people so far that have had defective regulators. I hope I am not another one.

PKRWUD · 09-27-2001, 12:05 PM

Of course it was a joke, unless you were applying vacuum from a vacuum cleaner.

Hey, I work on race cars. I never said I was funny.

The only time I've ever seen an adjustable fuel pressure regulator react like yours was when they had a ruptured diaphragm. I understand that you can't adjust it with or without the vac attached, but does the pressure change with the vac attached? If it remains the same, you have a bad reg. Do you have access to another adj. reg. for comparison?

Take care
~Chris

------------------
Retired Moderator
MustangNet

My site: JimPorterRacing

RACECAR spelled backwards is RACECAR

HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

Rebel79 · 09-27-2001, 01:26 PM

Phew! You had me scacred there Chris.

Yes the fuel pressure does change when the vacuum line is removed. Unfortunately I do not have access to another fuel pressure regulator. I am trying to get a hold of Kirban for advice. I'll let you know what they say.

89 Cobra LX · 09-27-2001, 01:36 PM

For what it's worth, I'm running a Kirban regulator and have no problems adjusting the pressure up or down. Probably a bad regulator...

------------------
Eric - 89 Mustang LX coupe
302 - Cobra Intake - GT40p heads - TFS stage 1 cam - FRPP 1.6 roller rockers - Naturally Aspirated
3:73 gears - KYB shocks and struts - Eibach springs - HPM Mega-bite Jr lower control arms - HPM upper control arms

Rebel79 · 09-27-2001, 03:52 PM

OK I noticed something else. At idle with vacuum on, my fuel pressure sits at 45psi. When I start off the line, the fuel pressure dips down a few psi. Under decent acceleration, the pressure drops to 30psi! But when I apply boost from the blower, the fuel pressure skyrockets as normal, thanks to my FMU.

I talked to Kirban, they don't think its a bad regulator, but won't ship me out a new one to be sure. Is this typical of a broken regulator? I don't want to buy a new one for $130 and have it not be the problem.

------------------
1994 Mustang Cobra
308ci, Vortech S-trim 11#, ported GT-40 heads, E-303 cam, FMS 1 5/8 headers, BBK Offroad H-pipe, 2-chamber flows, and several other goodies.
Rebel Racing. Home of Bay Area Mustangs

PKRWUD · 09-27-2001, 04:56 PM

Just out of curiosity, what is the "range" of that reg.? What was the output of your old pump? What is the output of the new one?

Take care
~Chris

------------------
Retired Moderator
MustangNet

My site: JimPorterRacing

RACECAR spelled backwards is RACECAR

HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

jimberg · 09-27-2001, 10:59 PM

You should set the fuel pressure with the engine off (no need to fiddle with vacuum line). You do this turning the ignition key to the on position and jumper the fuel pump test lead of the test connector to ground. This will force your fuel pump to run constantly. If you hold the test connector so that the bevel is up, the fuel pump test lead is the connector on the right.

------------------
351W 89 Mustang GT Convertible

Rebel79 · 09-28-2001, 09:45 AM

Chris,

I don't remember the range of the regulator. My fuel pressure was set at 38psi (vacuum off) with my stock fuel pump. Once I put in the Walboro 255lph pump the fuel pressure rose to 49psi with vacuum off.

PKRWUD · 09-28-2001, 09:58 AM

I think it's a bad reg.

Hey, you need to go see this Rear Window Thread I started in BOL. Trust me.

Take care
~Chris

------------------
Retired Moderator
MustangNet

My site: JimPorterRacing

RACECAR spelled backwards is RACECAR

HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

Rebel79 · 09-28-2001, 12:18 PM

I'm ordering a new reg today. Thanks for the link bud. Glad to see you are still sporting the decal. Man I had to reproduce some more cause a local kid wanted like 10 of them. I had forgotten how much I had spent and how much money I ate because of that! I think I originally made over 100 of them for $375. I only sold about 65 so I ate the rest. When I had some more made, they cost $6.25 ea. !! I could only afford 12.

PKRWUD · 09-28-2001, 12:54 PM

I can't believe you didn't sell more of them! I am asked about mine at least once a week. I think I bought 4 from you for around $20 including shipping. That one has been on my F-150 for close to 2 years now, and still looks as good as new. 2 of the others I bought became gifts, and I still have my last one, waiting for the right application. Actually, I am somewhat of a sticker-a-hollic, and have at least one of just about any sticker you could want. I never seem to be able to stick my last copy of any sticker, if you know what I mean.

Anyway, I started that thread in BOL because I couldn't think of any other way to post a picture of your sticker. Seeing you here again reminded me, and left me feeling like there are probably a bunch of newbies here who never even knew.

That was/is a great sticker, Scott. You should be proud! I know I certainly am.

Take care
~Chris

------------------
Retired Moderator
MustangNet

My site: JimPorterRacing

RACECAR spelled backwards is RACECAR

HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

09-26-2001, 11:54 AM	#1
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	Problems adjusting Fuel Pressure This weekend I tried adjusting my fuel pressure on my Kirban Adjustable Fuel Pressure Regulator. I took the vacuum line off and the FP was set to 48. I can turn the adjustment screw 5 full counter-clockwise rotations and it won't drop a psi. However I can adjust it back to where it was, and turn it 3 times to the right which makes it tight, and the FP goes up to 50psi! You see my FP was set at 38psi, but then I upgraded my fuel pump and it jumped up to 48! Its way too high and I need to lower it. ------------------ 1994 Mustang Cobra 308ci, Vortech S-trim 11#, ported GT-40 heads, E-303 cam, FMS 1 5/8 headers, BBK Offroad H-pipe, 2-chamber flows, and several other goodies. Rebel Racing. Home of Bay Area Mustangs

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09-26-2001, 09:38 PM	#2
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	ANYONE?

09-27-2001, 04:04 AM	#3
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Was this with the engine running? Take care ~Chris ------------------ Retired Moderator MustangNet My site: JimPorterRacing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

09-27-2001, 09:35 AM	#4
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	Chris, I certainly hope that was a joke. I tried ajusting the fuel pressure with the vacuum on, no change. I'm going to call Kirban to see what they have to say. I have only heard of two people so far that have had defective regulators. I hope I am not another one.

09-27-2001, 12:05 PM	#5
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Of course it was a joke, unless you were applying vacuum from a vacuum cleaner. Hey, I work on race cars. I never said I was funny. The only time I've ever seen an adjustable fuel pressure regulator react like yours was when they had a ruptured diaphragm. I understand that you can't adjust it with or without the vac attached, but does the pressure change with the vac attached? If it remains the same, you have a bad reg. Do you have access to another adj. reg. for comparison? Take care ~Chris ------------------ Retired Moderator MustangNet My site: JimPorterRacing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

09-27-2001, 01:26 PM	#6
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	Phew! You had me scacred there Chris. Yes the fuel pressure does change when the vacuum line is removed. Unfortunately I do not have access to another fuel pressure regulator. I am trying to get a hold of Kirban for advice. I'll let you know what they say.

09-27-2001, 01:36 PM	#7
89 Cobra LX Don Corlione Join Date: Jun 2001 Location: Omaha NE USA Posts: 491	For what it's worth, I'm running a Kirban regulator and have no problems adjusting the pressure up or down. Probably a bad regulator... ------------------ Eric - 89 Mustang LX coupe 302 - Cobra Intake - GT40p heads - TFS stage 1 cam - FRPP 1.6 roller rockers - Naturally Aspirated 3:73 gears - KYB shocks and struts - Eibach springs - HPM Mega-bite Jr lower control arms - HPM upper control arms

09-27-2001, 03:52 PM	#8
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	OK I noticed something else. At idle with vacuum on, my fuel pressure sits at 45psi. When I start off the line, the fuel pressure dips down a few psi. Under decent acceleration, the pressure drops to 30psi! But when I apply boost from the blower, the fuel pressure skyrockets as normal, thanks to my FMU. I talked to Kirban, they don't think its a bad regulator, but won't ship me out a new one to be sure. Is this typical of a broken regulator? I don't want to buy a new one for $130 and have it not be the problem. ------------------ 1994 Mustang Cobra 308ci, Vortech S-trim 11#, ported GT-40 heads, E-303 cam, FMS 1 5/8 headers, BBK Offroad H-pipe, 2-chamber flows, and several other goodies. Rebel Racing. Home of Bay Area Mustangs

09-27-2001, 04:56 PM	#9
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Just out of curiosity, what is the "range" of that reg.? What was the output of your old pump? What is the output of the new one? Take care ~Chris ------------------ Retired Moderator MustangNet My site: JimPorterRacing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

09-27-2001, 10:59 PM	#10
jimberg Registered Member Join Date: Oct 1998 Location: Rogers, MN Posts: 2,089	You should set the fuel pressure with the engine off (no need to fiddle with vacuum line). You do this turning the ignition key to the on position and jumper the fuel pump test lead of the test connector to ground. This will force your fuel pump to run constantly. If you hold the test connector so that the bevel is up, the fuel pump test lead is the connector on the right. ------------------ 351W 89 Mustang GT Convertible

09-28-2001, 09:45 AM	#11
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	Chris, I don't remember the range of the regulator. My fuel pressure was set at 38psi (vacuum off) with my stock fuel pump. Once I put in the Walboro 255lph pump the fuel pressure rose to 49psi with vacuum off.

09-28-2001, 09:58 AM	#12
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	I think it's a bad reg. Hey, you need to go see this Rear Window Thread I started in BOL. Trust me. Take care ~Chris ------------------ Retired Moderator MustangNet My site: JimPorterRacing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

09-28-2001, 12:18 PM	#13
Rebel79 News Editor Join Date: Apr 1999 Location: Concord, CA Posts: 2,101	I'm ordering a new reg today. Thanks for the link bud. Glad to see you are still sporting the decal. Man I had to reproduce some more cause a local kid wanted like 10 of them. I had forgotten how much I had spent and how much money I ate because of that! I think I originally made over 100 of them for $375. I only sold about 65 so I ate the rest. When I had some more made, they cost $6.25 ea. !! I could only afford 12.

09-28-2001, 12:54 PM	#14
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	I can't believe you didn't sell more of them! I am asked about mine at least once a week. I think I bought 4 from you for around $20 including shipping. That one has been on my F-150 for close to 2 years now, and still looks as good as new. 2 of the others I bought became gifts, and I still have my last one, waiting for the right application. Actually, I am somewhat of a sticker-a-hollic, and have at least one of just about any sticker you could want. I never seem to be able to stick my last copy of any sticker, if you know what I mean. Anyway, I started that thread in BOL because I couldn't think of any other way to post a picture of your sticker. Seeing you here again reminded me, and left me feeling like there are probably a bunch of newbies here who never even knew. That was/is a great sticker, Scott. You should be proud! I know I certainly am. Take care ~Chris ------------------ Retired Moderator MustangNet My site: JimPorterRacing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!