2000 Silverado 1500

[bsterner]

Hello,

 

I have been having problems with fuel pressure on my truck. I suspected it was the fuel pressure regulator so I installed a new one. Ever since then I can not hold the fuel pressure. Once the key is on for two seconds the fuel pressure will shoot up to 62 then go back down to 30. When I install the old regulator my fuel pressure will hold at 55. Are the new regulators supposed to do this? At the parts store they suggested that I put on the vacuum line but there is not a vacuum line. This regulator is located on the fuel body that holds the injectors inside the air intake manifold. Thanks

 

Added note: I had the parts store replace the new regulator I purchased with a different one and still the same result.

[GMTRUCKTECH]

Hello,

 

I have been having problems with fuel pressure on my truck. I suspected it was the fuel pressure regulator so I installed a new one. Ever since then I can not hold the fuel pressure. Once the key is on for two seconds the fuel pressure will shoot up to 62 then go back down to 30. When I install the old regulator my fuel pressure will hold at 55. Are the new regulators supposed to do this? At the parts store they suggested that I put on the vacuum line but there is not a vacuum line. This regulator is located on the fuel body that holds the injectors inside the air intake manifold. Thanks

 

Added note: I had the parts store replace the new regulator I purchased with a different one and still the same result.

 

POSS that check ball at fuel pump assm sticking pretty common or a injector line leaking.

[bsterner]

Hello,

 

I have been having problems with fuel pressure on my truck. I suspected it was the fuel pressure regulator so I installed a new one. Ever since then I can not hold the fuel pressure. Once the key is on for two seconds the fuel pressure will shoot up to 62 then go back down to 30. When I install the old regulator my fuel pressure will hold at 55. Are the new regulators supposed to do this? At the parts store they suggested that I put on the vacuum line but there is not a vacuum line. This regulator is located on the fuel body that holds the injectors inside the air intake manifold. Thanks

 

Added note: I had the parts store replace the new regulator I purchased with a different one and still the same result.

 

POSS that check ball at fuel pump assm sticking pretty common or a injector line leaking.

 

 

POSS? I am not sure what that means. I have replaced the fuel pump, fuel filter, and cleaned the injector poppets.

[GMTRUCKTECH]

Hello,

 

I have been having problems with fuel pressure on my truck. I suspected it was the fuel pressure regulator so I installed a new one. Ever since then I can not hold the fuel pressure. Once the key is on for two seconds the fuel pressure will shoot up to 62 then go back down to 30. When I install the old regulator my fuel pressure will hold at 55. Are the new regulators supposed to do this? At the parts store they suggested that I put on the vacuum line but there is not a vacuum line. This regulator is located on the fuel body that holds the injectors inside the air intake manifold. Thanks

 

Added note: I had the parts store replace the new regulator I purchased with a different one and still the same result.

 

POSS that check ball at fuel pump assm sticking pretty common or a injector line leaking.

 

 

POSS? I am not sure what that means. I have replaced the fuel pump, fuel filter, and cleaned the injector poppets.

 

 

 

POSS=MAYBE truck not in front of me so it's a maybe. Did you replace the injector assm with the updated one or just the pressure reg. There is a updated injector unit for your truck that comes as a hole assm injectors and reg. It is a far better. Let me see if I can find the bull.

[GMTRUCKTECH]

Hello,

 

I have been having problems with fuel pressure on my truck. I suspected it was the fuel pressure regulator so I installed a new one. Ever since then I can not hold the fuel pressure. Once the key is on for two seconds the fuel pressure will shoot up to 62 then go back down to 30. When I install the old regulator my fuel pressure will hold at 55. Are the new regulators supposed to do this? At the parts store they suggested that I put on the vacuum line but there is not a vacuum line. This regulator is located on the fuel body that holds the injectors inside the air intake manifold. Thanks

 

Added note: I had the parts store replace the new regulator I purchased with a different one and still the same result.

 

POSS that check ball at fuel pump assm sticking pretty common or a injector line leaking.

 

 

POSS? I am not sure what that means. I have replaced the fuel pump, fuel filter, and cleaned the injector poppets.

 

 

 

POSS=MAYBE truck not in front of me so it's a maybe. Did you replace the injector assm with the updated one or just the pressure reg. There is a updated injector unit for your truck that comes as a hole assm injectors and reg. It is a far better. Let me see if I can find the bull.

 

 

Here you go big guy. The plastic lines on the old units leak so replace with this.

This procedure outlines the steps required to replace the existing Central SFI Fuel System with a new MFI (Multiport Flexible Injection) Fuel System. Be sure to use the appropriate year and model Service Manual for proper disassembly and re-assembly procedure(s).

 

1. <LI type=1>Remove Upper Intake Manifold plenum and SFI Fuel Meter Body according to Service Manual Procedures. <LI type=1>Remove the Fuel Meter Body bracket and discard. Install the new bracket. <A href="

http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1234172&from=sm#oth12-1234172">

Figure 3

 

(1)Cyl. 2, 4, 6 and 8 tubes(2)Fuel Inlet(3)Cyl. 1, 3, 5 and 7 tubes(4)Fuel Pressure Regulator<LI type=1>Position Fuel Tubes of MFI Fuel Meter Body as shown in Figure 3. Fuel tubes 1, 3, 5, and 7 are oriented toward the fuel inlet side of the fuel meter body. Fuel tubes 2,4,6, and 8 are oriented toward the fuel pressure regulator side if the fuel meter body. <LI type=1>Insert the MFI Fuel Meter Body into the Fuel Meter Body Bracket on the Lower Intake Manifold being careful not to bind the Fuel Tubes. Push down firmly on the fuel meter body until the tabs snap into the bracket locking the fuel meter body in place.

(1)Cylinders 6 & 8(2)Fuel Pressure Regulator(3)Cylinders 2 & 4(4)Cylinders 5 & 7(5)Cylinders 1 & 3<LI type=1>Orient the fuel tubes to coincide with their corresponding cylinder. The fuel tubes are numbered on the side of the fuel meter body and the corresponding cylinder number is cast in the intake manifold. Notice: Use caution when inserting injectors into lower intake manifold to be sure the correct injector is being placed into the correct hole.

 

Injectors should not be removed once they have been installed.

 

 

 

Removal of injectors from the intake manifold may cause damage to the retaining lugs on the injector.

 

 

 

Important: The Injector holes are numbered on the Lower Intake Manifold. The injectors are numbered on the side of the Fuel Meter Body.

 

<LI type=1>Insert the fuel tubes into their corresponding holes in the intake manifold. Install tubes for cylinders 1, 3, 6 and 8 making sure that the injector electrical connectors are facing in toward the center of the manifold. <LI type=1>Insert fuel tubes for cylinders 2,4,5, and 7 in the same manner. Important: When installing fuel tubes, it is important that the tubes are oriented properly to provide minimal interference when installing the upper intake manifold plenum. Intake holes for cylinders 2, 4, 5, and 7 are closer to the fuel meter body. It is necessary to cross tube 5 over tube 7 and tube 4 over tube 2 as shown in Figure 4.

 

Notice: Lack of lubrication will make installation of the Upper Intake Manifold plenum difficult and may cause damage to the O-ring.

 

<LI type=1>Lubricate the Fuel Meter Body Upper Manifold O-ring (blue in color) with clean engine oil.

Inspect Upper Intake Manifold Gasket and replace if necessary. Reinstall the Upper Intake Manifold plenum following the procedures in the Service Manual. Important: Lubricate the Fuel Inlet and Return Lines with clean engine oil before inserting them in the of the Fuel Meter Body.

 

Make sure that Fuel Line Retaining Bracket is properly oriented with the tabs down.

 

 

 

<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1234172&from=sm#ss13-1234172">

Parts Information

Cleaning Procedure Parts

 

Part Number

 

Description

 

12345382

 

Threadlock

 

1050002

 

Top Engine Cleaner (U.S.)

 

992872

 

Top Engine Cleaner (Canada)

 

12345104

 

Port Fuel Injector Cleaner (U.S.)

 

10953467

 

Port Fuel Injector Cleaner (Canada)

 

CSFI to MFI Conversion Parts

 

Part Number

 

Description

 

12568332

 

V-6 MFI Assembly

 

88894355

 

V-6 Bracket

 

17113215

 

V-6 Seal Kit

 

93441235

 

V-8 MFI Assembly

 

17113206

 

V-8 Seal Kit

 

93442096

 

V-8 Bracket

 

Parts are currently available from GMSPO.

 

<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1234172&from=sm#ss14-1234172">

Warranty Information

Important: Some California vehicles may be covered by Special Policy 99066E if built with California Emissions RPO YF5. If the vehicle is covered by the special policy, then that warranty information should be used.

 

For vehicles repaired under warranty, use:

 

Labor Operation

 

Description

 

Labor Time

 

J5645

 

Injector, Fuel - Clean

 

C/K, S/T

 

1.3 hrs

 

Injector, Fuel - Clean

 

M/L, P

 

1.0 hr

 

Injector, Fuel - Clean

 

G Van

 

1.5 hrs

 

J5496

[bsterner]

This references an 8 cylinder. Is this different for a 6? As far as the upgraded unit is concerned? I ask because I have a 6 cylinder.

 

Also, I returned the part store pressure regulator and visited the Chevrolet dealership and purchased a new regulator from them. I installed it and was able to get the pressure to stabilize but still under the specs that I have in my Chilton. The reason why im going though all of this trouble is because both bank 1&2 are reporting lean conditions. The code suggest that the fuel pressure is not up to par or other issues>MAF>o2 sensor>fuel injector> since I had the gauge I checked the pressure and not able to get it up to spec. The book reports 60-66 but I can only get 52. I put everthing back together wednesday to see if the new regulator would help but the truck still will lag and will not let me go over 2k rpm (this only happens after a hour or so of driving, once you turn it off and back on the truck will run normal for 10 minutes then be back to the sluggish response). Its a slow acceleration. Any suggestions, Thanks

[bsterner]

Update: Just got back from the parts store with a new MAF sensor and Throttle Position Sensor. When I had them check the codes I got a new code p0122 referencing the TPS which is the first time I have seen this code. I would imagine it’s because I took the throttle body off to clean and maybe have messed it up. Not sure. Anyways, I put the MAF on at the store and started and stopped the motor a few times (Chilton references that if the code does not come up more then 5 successful runs, the codes will clear) and the check engine light turned off. I am running the truck now to see if the issue comes up again and crossing my fingers. This still does not explain the fuel pressure issue and may still come up again. Anyways, I will let you know what I find. Thanks for all of your help GMTRUCKTECH.

[bsterner]

Update 2: Just got back from some testing and notice new problems (go figure). Truck died on me twice. When you turn it on and go forward it is sluggish and the fuel gauge will move to empty and come back there where it needs to be. After that truck seems to run fine. I am still stuck on the fuel pressure issue and I think that once I fix that I will be back in business.

 

I remember when I was putting in the new regulator that towards the back of the part there is torq screw. Can this be adjusted to help bring up the pressure?

[GMTRUCKTECH]

This references an 8 cylinder. Is this different for a 6? As far as the upgraded unit is concerned? I ask because I have a 6 cylinder.

 

Also, I returned the part store pressure regulator and visited the Chevrolet dealership and purchased a new regulator from them. I installed it and was able to get the pressure to stabilize but still under the specs that I have in my Chilton. The reason why im going though all of this trouble is because both bank 1&2 are reporting lean conditions. The code suggest that the fuel pressure is not up to par or other issues>MAF>o2 sensor>fuel injector> since I had the gauge I checked the pressure and not able to get it up to spec. The book reports 60-66 but I can only get 52. I put everthing back together wednesday to see if the new regulator would help but the truck still will lag and will not let me go over 2k rpm (this only happens after a hour or so of driving, once you turn it off and back on the truck will run normal for 10 minutes then be back to the sluggish response). Its a slow acceleration. Any suggestions, Thanks

It gives you the part numbers for the v-6 in the bull I posted but here you go again.

V-6 MFI Assembly

 

88894355

 

V-6 Bracket

 

17113215

 

V-6 Seal Kit

 

93441235