Fuel pressure question

SilverSN95 · 08-17-2004, 08:51 PM

I just checked my car since I think my pump isn't too healthy. Here is what I got:

Key on engine off was 35psi
Key on engine running was 32-33psi

At WOT it would spike to 40psi and then drop to almost 30psi.

These numbers seem low to me and I wonder if it might be why I have a slight detonation problem.

88fivepointoh · 08-17-2004, 09:51 PM

That is what the stock settings are. What are your symtoms that your car is having if any?

SilverSN95 · 08-17-2004, 10:40 PM

First symptom is the pump has the typical buzz to it but it seems to be a little louder lately.

Second is the slight detonation I experience under the following:
1. warm ambient temperature, with and without the a/c on
2. only under load above 2500 rpm and only in 2nd gear and above. never seen to get it in 1st.
3. engine has heat soaked after a drive.
It doesn't happen when the engine is cold

I've tried to run the codes but I'm not sure if I'm doing it correctly. With the KOEO test I get either code 111 or 33 depending on how you interpret the light. It means either there is nothing wrong or my EGR valve is screwed. I have not done the KOER test yet.

Also, my timing is at 10 degrees and I have Autolight 24's installed along with new wires,cap&rotor.

If I run 94 octane the detonation goes away.

stang_racer20 · 08-18-2004, 12:53 AM

did you check and set your base timing with the spout disconnected? A common mistake.

Ackbar00 · 08-18-2004, 05:30 AM

Timing stock is 10
FP stock is 38 at idel

Your Fuel pump could be suspect. I would go with a 190. Your gonna need it sooner or later.

SilverSN95 · 08-18-2004, 06:13 AM

Yes, Timing was set with spout connector out.

Also forgot to mention that it will stall while idling when hot once and awhile for no reason. I thought it was the ignition module so that was changed... and it still stalled on me last week. Fired back up with little problem but I don't understand why it stalls. It doesn't even stumble or anything, just stops running.

88fivepointoh · 08-19-2004, 03:28 PM

Guy down the road had the same issue on his 95, the fuel pump was bad trippin the fuel pump relay. It was drawing to much amperage and tripping the relay causing it to stall... If its getting louder thats the sign to replace it.

08-17-2004, 08:51 PM	#1
SilverSN95 Registered Member Join Date: May 2002 Location: Ontario Posts: 39	Fuel pressure question I just checked my car since I think my pump isn't too healthy. Here is what I got: Key on engine off was 35psi Key on engine running was 32-33psi At WOT it would spike to 40psi and then drop to almost 30psi. These numbers seem low to me and I wonder if it might be why I have a slight detonation problem. __________________ Al, 94 Mustang GT 3.55 gears Magnapack mufflers with 2.5" tails STEEDA TRI-AX Shifter MAC pulleys

08-17-2004, 10:40 PM	#3
SilverSN95 Registered Member Join Date: May 2002 Location: Ontario Posts: 39	First symptom is the pump has the typical buzz to it but it seems to be a little louder lately. Second is the slight detonation I experience under the following: 1. warm ambient temperature, with and without the a/c on 2. only under load above 2500 rpm and only in 2nd gear and above. never seen to get it in 1st. 3. engine has heat soaked after a drive. It doesn't happen when the engine is cold I've tried to run the codes but I'm not sure if I'm doing it correctly. With the KOEO test I get either code 111 or 33 depending on how you interpret the light. It means either there is nothing wrong or my EGR valve is screwed. I have not done the KOER test yet. Also, my timing is at 10 degrees and I have Autolight 24's installed along with new wires,cap&rotor. If I run 94 octane the detonation goes away. __________________ Al, 94 Mustang GT 3.55 gears Magnapack mufflers with 2.5" tails STEEDA TRI-AX Shifter MAC pulleys

08-18-2004, 12:53 AM	#4
stang_racer20 Registered Member Join Date: Jun 2003 Location: Wisconsin Posts: 348	did you check and set your base timing with the spout disconnected? A common mistake. __________________ 92 Mustang GT, 347 Stroker(Forged Steel Crank/Rods-Balanced, Forged Aluminum Dished Pistons), Trick Flow Track Heat Intake, Trick Flow Twisted Wedge Heads w/ Stage 3 port/polish, 80mm C&L MAF, FMS 30# Inj., BBK AFPR, Trick Flow Stage 2 Cam, Trick Flow 1.6R Rockers, BBK E.L. Headers, Flowmaster Cat-Back, MAC CAI, FMS Pulleys, Griffin Alum. Radiator, MSD Pro-Billet Distributor; AOD, Dynamic 3300 Lockup Converter, B & M Super Cooler, B&M Ratchet Shifter; 3:73 gears.

08-18-2004, 05:30 AM	#5
Ackbar00 Rebel Fleet Commander Join Date: Oct 2001 Location: Huber Heights, OH Posts: 1,003	Timing stock is 10 FP stock is 38 at idel Your Fuel pump could be suspect. I would go with a 190. Your gonna need it sooner or later. __________________ 1993 Mustang GT, PTK w/ T-64 - My Cardomain Webpage 11.25@123.5 on only 8 psi. 10.84@121 on only 1 headgasket "The Truth is, Your the Weak, and I am the Tyranny of Evil Men!"

08-18-2004, 06:13 AM	#6
SilverSN95 Registered Member Join Date: May 2002 Location: Ontario Posts: 39	Yes, Timing was set with spout connector out. Also forgot to mention that it will stall while idling when hot once and awhile for no reason. I thought it was the ignition module so that was changed... and it still stalled on me last week. Fired back up with little problem but I don't understand why it stalls. It doesn't even stumble or anything, just stops running. __________________ Al, 94 Mustang GT 3.55 gears Magnapack mufflers with 2.5" tails STEEDA TRI-AX Shifter MAC pulleys

08-17-2004, 09:51 PM	#2
88fivepointoh Registered Member Join Date: Aug 2002 Location: Rochester Posts: 553	That is what the stock settings are. What are your symtoms that your car is having if any?

08-19-2004, 03:28 PM	#7
88fivepointoh Registered Member Join Date: Aug 2002 Location: Rochester Posts: 553	Guy down the road had the same issue on his 95, the fuel pump was bad trippin the fuel pump relay. It was drawing to much amperage and tripping the relay causing it to stall... If its getting louder thats the sign to replace it.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Speed Secret # 3	jim_howard_pdx	Windsor Power	13	11-09-2002 10:35 AM
Fuel pressure question	MEDIK418	Windsor Power	2	10-26-2002 02:45 PM
is my fuel pressure too high under boost?	bullitt843	Windsor Power	4	04-26-2002 07:32 PM
Fuel pressure at high altitude. etc...	Dark_5.0	Windsor Power	5	04-19-2002 07:52 AM
fuel pressure, TPS setting, and timing for supercharger	gramsch	Windsor Power	5	05-07-2001 12:16 PM