: Throttle body cleaning issue



oldworld
08-20-09, 09:34 PM
Within the past two weeks I had a new fuel pump installed. The very same day I noticed that the truck took a little longer to start, and at times when I let go of the key while atrting, the truck would continue to turn until the truck started. I inquired at the shop and they told me that the start was computer controlled until it started, the key only initiates the starter and the computer takes over to start it. THIS TRUE??
Then I notice that it takes a few times to get it started.
Coincidence or not, but I did a throttle body cleaning the day after I had the fuel pump installed. It was VERY dirty. Cleaned it out fine. Truck idles perfect but still takes sometimes 2-3 times to get it started.
Never had an issue with starting ever...UNTIL I had the new fuel pump installed....or the throttle body cleaned.
Did I do something wrong while cleaning the throttle body?
Is there an issue with the fuel pump that could cause this???

THANKS

sk7
08-20-09, 09:54 PM
I don't think our generation escalades have computer controlled starting. Only GM vehicules I've seen with this feature have no starter wire at the ignition switch, just a resistance value fed thru the key sense wire to initiate the starting sequence. Its almost like a passlock 2 on top of the transponder passlock 3 system!

Did you replace your fuel pump with OEM one? Maybe the fuel pressure is low, or crap got stuck in the filter? I removed the intake on my 6.0 to replace the knock sensors, cleaned it as much as I could and truck runs a lot better. No issues at all. Maybe check fuel pressure at the valve on the fuel rail?

oldworld
08-20-09, 10:02 PM
I guess I should replace filter anyway. Its been about 18 months....that sound OK?
It was NOT replaced with an AC DELCO pump, but an after market, one that the mechanic felt very comfortable doing. The warranty co would only allow for an aftermarket pump.
So I guess the pump could be bad. Suggest then bringing it back to shop to test fuel pressure????

sk7
08-20-09, 10:44 PM
Yep I would start there, maybe the pump is bad? Keep us posted...

luxurylife33
08-20-09, 11:17 PM
I'd be willing to say its low on fuel pressure. Happened on my integra once.... took a good 6-7 seconds of cranking to get it started, turns out one of the fuel lines wasn't tight enough and was losing pressure each time the car was sitting.

oldworld
08-21-09, 07:24 AM
If it was indeed low fuel pressure, wouldn't there be a check engine light?
I also became aware that even though there is no check engine light on that would throw a code, there are often codes within the system that help diagnose issues.
What prompted this fuel pump replacement was the fact that the prior replacement had a fuel tank level sensor go, and the truck always said I was on empty. No check engine light. Then the sensor for the fuel tank pressure sensor went 2 days later. That had a check engine light.
Thus the new fuel pump.
This is the THIRD fuel pump installed within the last 8 months. The shop owner inquired about this fuel pump, which is very popular, and they make 1.5 million of them last year. 443 Were returned as defective. FUNNY, I got at least two of them, now maybe three??? :hmm: :banghead:
QUESTION: Is there an internal code for low fuel pressure??? Reason I ask is I am going away this weekend to the shore for a few days. I was thinking of taking it back to the shop and see if they can diagnose with their scanner.
If it is low fuel pressure, is it safe to drive this weekend without fear of getting stuck??
THANKS

smelly$cat
08-21-09, 11:22 AM
I have a 03 ESV and a 04 Suburban.

My 04 suburban has the same symptom as you. I pretty much have to try to start it 2x all the time. Some times it starts on the first crank, but only about 30% of the time. It wasn't always this way. Although, I've only owned it for ~5k miles. It only has 27k miles on it. I've never had it leave me stranded, so, based on my experience, I wouldn't worry about it, but I would bring it back to your mechanic. Also, it does what you described (continues cranking when I let off the key for a couple seconds). I think that's normal. I haven't tried letting go of the key on my ESV since I just got it about a month ago. The ESV starts super easy.

I haven't tried to troubleshoot the starting issue on the suburban yet. I'll get to it eventually.

I am going to subscribe to this thread to see how things turn out for you. Hopefully you keep us all posted on your final solution !

oldworld
08-21-09, 08:58 PM
UPDATE:
Took the truck to the same shop that replaced the fuel pump, and they did a fuel pressure test, which was pretty simple to do:
VERDICT: Bad fuel pump.
Turned over at least 2-3 times with no start....pressure was very low.
About the fourth try, pressure was high and truck started.

This is the fourth one in 8 months.....aftermarket pump.
They will install an ac/delco pump now next week, and not charge me the difference in cost. What a pain!!!!:bonkers:

luxurylife33
08-22-09, 02:26 AM
I was gunna say after the 1st incident, you should have just supplied them the Delphi pump if they weren't going to cover it.... the labor is what costs the most for a job like this... a new oem delphi pump is about $150

smelly$cat
08-22-09, 12:34 PM
Thanks for the update man. I'd hate to think my suburban fuel pump is dying at 27k miles. But in some strange way, it doesn't surprise me.

Did you see how the tech tested the fuel pressure? Is there just a fitting in the engine compartment that they connect a tool to to test?

Might get mine tested to get a verdict on this situation for me....

Thanks!





UPDATE:
Took the truck to the same shop that replaced the fuel pump, and they did a fuel pressure test, which was pretty simple to do:
VERDICT: Bad fuel pump.
Turned over at least 2-3 times with no start....pressure was very low.
About the fourth try, pressure was high and truck started.

This is the fourth one in 8 months.....aftermarket pump.
They will install an ac/delco pump now next week, and not charge me the difference in cost. What a pain!!!!:bonkers:

sk7
08-25-09, 10:00 PM
There is a valve on the fuel rail right on top of the intake. Just like an air valve on tires. This is where the pressure is monitored for the test. Here are the troubleshooting / specs data:

Fuel System Diagnosis Step
Action
Values
Yes
No

Schematic Reference: Fuel Hose/Pipes Routing Diagram

1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls

2

Important
Before you proceed with this diagnostic, inspect the fuel system for damage and for external leaks.


Turn ON the ignition, with the engine OFF.
Command the fuel pump relay ON with a scan tool.
Does the fuel pump turn ON when commanded with a scan tool?
Go to Step 3
Go to Intermittent Conditions

3

Important
Before you proceed with this diagnostic, inspect the fuel system for damage and for external leaks.


Turn OFF the ignition.
Turn OFF all accessories.

Caution
Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete.


Install the J 34730-1A Fuel Pressure Gage. Refer to Fuel Pressure Gage Installation and Removal .
Turn ON the ignition, with the engine OFF.

Important
You may need to command the fuel pump ON several times, in order to obtain the highest possible fuel pressure.
Do NOT start the engine.

Command the fuel pump ON with a scan tool.
Observe the fuel pressure gage with the fuel pump commanded ON.
Is the fuel pressure within the specified value?
385-425 kPa

(55-62 psi) VIN: (V, T,U)

335-375 (48-54 psi) VIN: Z
Go to Step 4
Go to Step 12

4

Important
The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize, then remain constant.


Observe the fuel pressure gage for 1 minute.

Does the fuel pressure drop more than the specified value?
34 kPa

(5 psi)
Go to Step 9
Go to Step 5

5
Relieve the fuel pressure to the first specified value.
Observe the fuel pressure gage for 1 minute.
Does the fuel pressure drop more than the second specified value?
69 kPa

(10 psi)

14 kPa

(2 psi)
Go to Step 24
Go to Step 6

6
Turn OFF the ignition for 15 seconds.
Turn ON the ignition, with the engine OFF.
Monitor the fuel pressure gage.
Start the engine.
Does the fuel pressure drop the specified value when the engine is started?
21-69 kPa

(3-10 psi)
Go to Step 7
Go to Step 8

7
Operate the vehicle within the conditions of the customer's concerns.
Monitor the fuel-related parameters with a scan tool.
Do any of the scan tool parameters indicate a lean condition?
--
Go to Step 17
Go to Symptoms - Engine Controls

8
Disconnect the vacuum hose from the fuel pressure regulator.
Monitor the fuel pressure gage.
Idle the engine.
Apply 12-14 inches of vacuum to the fuel pressure regulator with a hand-held vacuum pump.
Does the fuel pressure drop the specified value when the vacuum is applied?
21-69 kPa (3-10 psi)
Go to Step 21
Go to Step 23

9
Turn OFF the ignition.
Disconnect the vacuum hose from the fuel pressure regulator.
Turn ON the ignition, with the engine OFF.
Command the fuel pump ON with a scan tool.
Inspect for a fuel leak from the vacuum port of the fuel pressure regulator .
Is the fuel pressure regulator leaking fuel?
--
Go to Step 23
Go to Step 10

10
Turn OFF the ignition.
Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure .
Disconnect the fuel feed hose and the fuel return hose from the fuel rail. Refer to Quick Connect Fitting(s) Service (Metal Collar) .
Install the J 37287 Fuel Line Shut-Off Adapters between the fuel hoses and the fuel rail pipes.
Open the valves on the fuel pipe shut-off adapters.
Turn ON the ignition, with the engine OFF.
Command the fuel pump ON with a scan tool.
Bleed the air from the fuel pressure gage.
Command the fuel pump ON and OFF with a scan tool.
Close the fuel feed pipe shut-off valve.
Monitor the fuel pressure gage for 1 minute.
Does the fuel pressure remain constant?
--
Go to Step 19
Go to Step 11

11
Turn OFF the ignition.
Open the shut-off valve for the fuel feed pipe.
Turn ON the ignition, with the engine OFF.
Command the fuel pump ON and OFF with a scan tool.
Close the shut-off valve for the fuel return pipe.
Monitor the fuel pressure gage for 1 minute.
Does the fuel pressure remain constant?
--
Go to Step 23
Go to Step 20

12
Is the fuel pressure more than the specified value?
427 kPa (62 psi) VIN: (V, T,U)

375 kPa (54 psi) VIN: Z
Go to Step 14
Go to Step 13

13
Is the fuel pressure more than the specified value?
0 kPa (0 psi)
Go to Step 16
Go to Step 17

14
Turn OFF the ignition.
Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure .
Disconnect the fuel return hose from the fuel rail return pipe. Refer to Quick Connect Fitting(s) Service (Metal Collar) .
Attach a length of flexible fuel hose to the fuel rail outlet passage.
Place the open end of the flexible fuel hose into an approved gasoline container.
Turn ON the ignition, with the engine OFF.
Monitor the fuel pressure gage with the fuel pump operating.
Is the fuel pressure within the specified value?
385-425 kPa (55-62 psi) VIN: (V, T,U)

335-375 kPa (48-54 psi) VIN: Z
Go to Step 22
Go to Step 15

15
Inspect the fuel rail outlet passage for a restriction.

Did you find and correct the condition?
--
Go to Step 25
Go to Step 23

16
Turn OFF the ignition.
Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure .
Disconnect the fuel return hose from the fuel rail return pipe. Refer to Quick Connect Fitting(s) Service (Metal Collar) .
Install the J 37287 between the fuel return pipe and the fuel rail.
Open the valve on the fuel pipe shut-off adapter.
Turn ON the ignition, with the engine OFF.
Command the fuel pump ON with a scan tool.
Bleed the air from the fuel system.
Monitor the fuel pressure gage.

Notice
DO NOT allow the fuel pressure to exceed 517 kPa (75 psi). Excessive pressure may damage the fuel system.


Slowly close the valve in the fuel pipe shut-off adapter.
Command the fuel pump ON with a scan tool.
Does the fuel pressure rise above the specified value?
425 kPa (62 psi) VIN: (V, T,U)

375 kPa (54 psi) VIN: Z
Go to Step 23
Go to Step 17

17
Inspect the following components for restrictions:

The fuel filter
The fuel feed pipe
Did you find and correct the condition?
--
Go to Step 25
Go to Step 18

18
Test for an intermittent and for a poor connection at the harness connectors and the ground circuits of the fuel pump. Refer to Testing for Intermittent and Poor Connections , and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 25
Go to Step 19

19
Remove the fuel sender assembly. Refer to Fuel Sender Assembly Replacement .
Inspect the following components:
The fuel pump flex hose for damage
The in-tank fuel pump harness connectors for bad connections
The fuel strainer for restrictions
The fuel tank for contaminants
Did you find and correct the condition?
--
Go to Step 25
Go to Step 24

20
Turn OFF the ignition.
Raise the fuel rail, with the fuel lines connected. Refer to Fuel Rail Assembly Replacement .
Turn ON the ignition, with the engine OFF.
Command the fuel pump relay ON with a scan tool.
Locate and replace the leaking fuel injector. Refer to Fuel Injector Replacement .
Did you complete the replacement?
--
Go to Step 25
--

21
Repair the vacuum source to the fuel pressure regulator.

Did you complete the repair?
--
Go to Step 25
--

22
Locate and repair the restricted fuel return line.

Did you complete the repair?
--
Go to Step 25
--

23

Important
Before your replace the fuel pressure regulator, inspect for a missing or damaged fuel pressure regulator O-ring seal.


Replace the fuel pressure regulator. Refer to Fuel Pressure Regulator Replacement .

Did you complete the replacement?
--
Go to Step 25
--

24
Replace the fuel pump. Refer to Fuel Sender Assembly Replacement .

Did you complete the replacement?
--
Go to Step 25
--

25
Operate the system in order to verify the repair.

Did you correct the condition?
--
System OK
Go to Step 3

I have rarely encountered a MIL light for a low fuel pressure on a pump. Unless the thing just dies and engine doesnt run anymore, its an easy one to overlook. Glad you got this taken care of.

smelly$cat
08-26-09, 10:45 AM
Dang good info! You work for a dealer as well or just have a copy of the service manual?
----






There is a valve on the fuel rail right on top of the intake. Just like an air valve on tires. This is where the pressure is monitored for the test. Here are the troubleshooting / specs data:

Fuel System Diagnosis Step
Action
Values
Yes
No

Schematic Reference: Fuel Hose/Pipes Routing Diagram

1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls

2

Important
Before you proceed with this diagnostic, inspect the fuel system for damage and for external leaks.


Turn ON the ignition, with the engine OFF.
Command the fuel pump relay ON with a scan tool.
Does the fuel pump turn ON when commanded with a scan tool?
Go to Step 3
Go to Intermittent Conditions

3

Important
Before you proceed with this diagnostic, inspect the fuel system for damage and for external leaks.


Turn OFF the ignition.
Turn OFF all accessories.

Caution
Wrap a shop towel around the fuel pressure connection in order to reduce the risk of fire and personal injury. The towel will absorb any fuel leakage that occurs during the connection of the fuel pressure gage. Place the towel in an approved container when the connection of the fuel pressure gage is complete.


Install the J 34730-1A Fuel Pressure Gage. Refer to Fuel Pressure Gage Installation and Removal .
Turn ON the ignition, with the engine OFF.

Important
You may need to command the fuel pump ON several times, in order to obtain the highest possible fuel pressure.
Do NOT start the engine.

Command the fuel pump ON with a scan tool.
Observe the fuel pressure gage with the fuel pump commanded ON.
Is the fuel pressure within the specified value?
385-425 kPa

(55-62 psi) VIN: (V, T,U)

335-375 (48-54 psi) VIN: Z
Go to Step 4
Go to Step 12

4

Important
The fuel pressure may vary slightly when the fuel pump stops operating. After the fuel pump stops operating, the fuel pressure should stabilize, then remain constant.


Observe the fuel pressure gage for 1 minute.

Does the fuel pressure drop more than the specified value?
34 kPa

(5 psi)
Go to Step 9
Go to Step 5

5
Relieve the fuel pressure to the first specified value.
Observe the fuel pressure gage for 1 minute.
Does the fuel pressure drop more than the second specified value?
69 kPa

(10 psi)

14 kPa

(2 psi)
Go to Step 24
Go to Step 6

6
Turn OFF the ignition for 15 seconds.
Turn ON the ignition, with the engine OFF.
Monitor the fuel pressure gage.
Start the engine.
Does the fuel pressure drop the specified value when the engine is started?
21-69 kPa

(3-10 psi)
Go to Step 7
Go to Step 8

7
Operate the vehicle within the conditions of the customer's concerns.
Monitor the fuel-related parameters with a scan tool.
Do any of the scan tool parameters indicate a lean condition?
--
Go to Step 17
Go to Symptoms - Engine Controls

8
Disconnect the vacuum hose from the fuel pressure regulator.
Monitor the fuel pressure gage.
Idle the engine.
Apply 12-14 inches of vacuum to the fuel pressure regulator with a hand-held vacuum pump.
Does the fuel pressure drop the specified value when the vacuum is applied?
21-69 kPa (3-10 psi)
Go to Step 21
Go to Step 23

9
Turn OFF the ignition.
Disconnect the vacuum hose from the fuel pressure regulator.
Turn ON the ignition, with the engine OFF.
Command the fuel pump ON with a scan tool.
Inspect for a fuel leak from the vacuum port of the fuel pressure regulator .
Is the fuel pressure regulator leaking fuel?
--
Go to Step 23
Go to Step 10

10
Turn OFF the ignition.
Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure .
Disconnect the fuel feed hose and the fuel return hose from the fuel rail. Refer to Quick Connect Fitting(s) Service (Metal Collar) .
Install the J 37287 Fuel Line Shut-Off Adapters between the fuel hoses and the fuel rail pipes.
Open the valves on the fuel pipe shut-off adapters.
Turn ON the ignition, with the engine OFF.
Command the fuel pump ON with a scan tool.
Bleed the air from the fuel pressure gage.
Command the fuel pump ON and OFF with a scan tool.
Close the fuel feed pipe shut-off valve.
Monitor the fuel pressure gage for 1 minute.
Does the fuel pressure remain constant?
--
Go to Step 19
Go to Step 11

11
Turn OFF the ignition.
Open the shut-off valve for the fuel feed pipe.
Turn ON the ignition, with the engine OFF.
Command the fuel pump ON and OFF with a scan tool.
Close the shut-off valve for the fuel return pipe.
Monitor the fuel pressure gage for 1 minute.
Does the fuel pressure remain constant?
--
Go to Step 23
Go to Step 20

12
Is the fuel pressure more than the specified value?
427 kPa (62 psi) VIN: (V, T,U)

375 kPa (54 psi) VIN: Z
Go to Step 14
Go to Step 13

13
Is the fuel pressure more than the specified value?
0 kPa (0 psi)
Go to Step 16
Go to Step 17

14
Turn OFF the ignition.
Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure .
Disconnect the fuel return hose from the fuel rail return pipe. Refer to Quick Connect Fitting(s) Service (Metal Collar) .
Attach a length of flexible fuel hose to the fuel rail outlet passage.
Place the open end of the flexible fuel hose into an approved gasoline container.
Turn ON the ignition, with the engine OFF.
Monitor the fuel pressure gage with the fuel pump operating.
Is the fuel pressure within the specified value?
385-425 kPa (55-62 psi) VIN: (V, T,U)

335-375 kPa (48-54 psi) VIN: Z
Go to Step 22
Go to Step 15

15
Inspect the fuel rail outlet passage for a restriction.

Did you find and correct the condition?
--
Go to Step 25
Go to Step 23

16
Turn OFF the ignition.
Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure .
Disconnect the fuel return hose from the fuel rail return pipe. Refer to Quick Connect Fitting(s) Service (Metal Collar) .
Install the J 37287 between the fuel return pipe and the fuel rail.
Open the valve on the fuel pipe shut-off adapter.
Turn ON the ignition, with the engine OFF.
Command the fuel pump ON with a scan tool.
Bleed the air from the fuel system.
Monitor the fuel pressure gage.

Notice
DO NOT allow the fuel pressure to exceed 517 kPa (75 psi). Excessive pressure may damage the fuel system.


Slowly close the valve in the fuel pipe shut-off adapter.
Command the fuel pump ON with a scan tool.
Does the fuel pressure rise above the specified value?
425 kPa (62 psi) VIN: (V, T,U)

375 kPa (54 psi) VIN: Z
Go to Step 23
Go to Step 17

17
Inspect the following components for restrictions:

The fuel filter
The fuel feed pipe
Did you find and correct the condition?
--
Go to Step 25
Go to Step 18

18
Test for an intermittent and for a poor connection at the harness connectors and the ground circuits of the fuel pump. Refer to Testing for Intermittent and Poor Connections , and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 25
Go to Step 19

19
Remove the fuel sender assembly. Refer to Fuel Sender Assembly Replacement .
Inspect the following components:
The fuel pump flex hose for damage
The in-tank fuel pump harness connectors for bad connections
The fuel strainer for restrictions
The fuel tank for contaminants
Did you find and correct the condition?
--
Go to Step 25
Go to Step 24

20
Turn OFF the ignition.
Raise the fuel rail, with the fuel lines connected. Refer to Fuel Rail Assembly Replacement .
Turn ON the ignition, with the engine OFF.
Command the fuel pump relay ON with a scan tool.
Locate and replace the leaking fuel injector. Refer to Fuel Injector Replacement .
Did you complete the replacement?
--
Go to Step 25
--

21
Repair the vacuum source to the fuel pressure regulator.

Did you complete the repair?
--
Go to Step 25
--

22
Locate and repair the restricted fuel return line.

Did you complete the repair?
--
Go to Step 25
--

23

Important
Before your replace the fuel pressure regulator, inspect for a missing or damaged fuel pressure regulator O-ring seal.


Replace the fuel pressure regulator. Refer to Fuel Pressure Regulator Replacement .

Did you complete the replacement?
--
Go to Step 25
--

24
Replace the fuel pump. Refer to Fuel Sender Assembly Replacement .

Did you complete the replacement?
--
Go to Step 25
--

25
Operate the system in order to verify the repair.

Did you correct the condition?
--
System OK
Go to Step 3

I have rarely encountered a MIL light for a low fuel pressure on a pump. Unless the thing just dies and engine doesnt run anymore, its an easy one to overlook. Glad you got this taken care of.

oldworld
08-26-09, 07:54 PM
Question: Where did you find oem fuel pump fpr $150.00???:confused:
My replacement was covered in full but ubder warranty. They gave me a price to the warranty co of almost $600 with the pump.
I called 3-4 local auto parts dealers for the cost of an aftermarket pump, and they all were around $250.00. The shop asked if I wanted to spend and EXTRA $150 for the AC/Delco Pump, and I declined.
After the fact, I should have. Just got word today after returning from the shore that the parts supplier is indeed going to send the OEM pump in place of the aftermarket pump, with no additional charge. It is being installed on FRIDAY. I will keep you all posted and let you know what happens with the AC/Delco fuel pump vs aftermarket pump.
THANKS for all the help and information.

:bighead:

sk7
08-26-09, 08:02 PM
Wow outta 1.5 million units produced, 400 defects and you had to get 3 of them in a row??? Better go get a lottery ticket, you are most likely to hit the jackpot!! I got a copy of the GM service manual on DVD from BlownC5. Priceless information... Keep us posted!

oldworld
08-28-09, 07:16 AM
Bought the lottery tickets.............NO WINNER :banghead:
Story of my life lol

oldworld
08-28-09, 03:21 PM
UPDATE: AUGUST 28, 2009
New Ac/Delco Pump installed. Working 100% perfect. Starts like a charm again. Finally!!! :thumbsup:

smelly$cat
08-28-09, 04:02 PM
Thanks for the continued updates on this. Let's hope this one lasts eh?
--



UPDATE: AUGUST 28, 2009
New Ac/Delco Pump installed. Working 100% perfect. Starts like a charm again. Finally!!! :thumbsup:

sk7
08-28-09, 06:57 PM
Darnit you didnt win that lottery jackpot! I was gonna beg for a tech 2 scanner... Glad to hear truck is running good again. I'll keep that in mind if my fuel pump goes to replace with OEM stuff!