Fuel Pump or NOT Fuel PUMP

[longstand]

Hello EVERYONE, Longtime no TALK!!!!!

I finally Replace my ENGINE> YAY!

I finally got new carpet, New Seats, New Headliner, New PAINT. NEW Tire, ALL new Shocks and struts. New Gear Box, HONESTLY.. NEW EVERYTHING. THING ABOUT IT. and its New beside electrical

Now the ISSUE!

I have installed a new fuel pump. Car was running great. Now its not.

So I Replace Fuel Pump Relay, New Spark Plugs, New Spark Plug Wire, WHOLE new Distributor with NEW Sensors. I MADE SURE ALL SENSOR IS CONNECTED

I removed the Fuel line which connects to the Intake and see if fuel was coming out. NO FUEL.

I TRIPLE CHECK EVERY SINGLE SENSOR and WIRE. maybe QUADRUPLE

I got a DUDE to turn the key and I was under the Fuel tank to see if i hear any BUZZ sound stating that fuel pump is working.. NO SOUND. AHHH I even HIT IT/TAP TAP.. no luck

HELP.. I Ain't going to sell my DENALI. but damn this car cost me more than whats its worth. but its ok. I LOVE THIS SUV

I will upload a photo of it too later this week..

 

[SunlitComet]

make sure the ground wire from pump to frame rail near by was not damaged. and remember the pcm has full control over the relay so when the key is turned on feel for the relay click or listen with a mechanics stethoscope. here is a diagram and stuff to help.

Instrument Cluster: Analog (Fuel Gauge Sender (Single Tank, Gas))

Circuit Description
When the ignition switch is turned ON, the VCM energizes the fuel pump relay which powers the in-tank fuel pump ON. The in-tank fuel pump remains ON as long as the engine is cranking or running and the VCM is receiving the distributor reference pulses. If there are no reference pulses, the VCM shuts the fuel pump OFF within 2 seconds after the ignition was turned ON or if the engine stops. The VCM will also turn ON the fuel pump for 2 seconds when the ignition is turned to the OFF position.

Diagnostic Aids
If the fuel pump relay circuit checks out OK, refer to Fuel System Diagnosis. See: Component Tests and General Diagnostics
Excessive fuel may also cause long cranking times which is accompanied by the following conditions:

• A start that is not as fast as normal.
• A puff of black smoke at the tailpipe.

An improperly connected or faulty EVAP component can cause this problem. Refer to EVAP Control System Diagnosis. See: Component Tests and General Diagnostics

One or more leaking poppet nozzles (CSFI injectors) may also extend the cranking time. Perform the Injector Balance Test. Refer to Fuel Injector Balance Test with Tech 2. See: Component Tests and General Diagnostics

Test Description
Number(s) below refer to step number(s) on the Diagnostic Table.

1. The Powertrain OBD System Check prompts the technician to complete some basic checks and stores the freeze frame and failure records data on the scan tool, if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored in the scan tool for later reference.

3. If the no start condition was due to a open fuse, locate and repair any shorts that may have caused the fuse to open before replacement.

4. This step determines if the fuel pump circuit can be controlled by the VCM. The VCM should energize the fuel pump relay and turn the fuel pump ON when commanded by the scan tool. If the engine is not cranking or running, the VCM should de-energize the relay and turn OFF the fuel pump after 2 seconds.

5.Jumpering the fuel pump positive voltage terminal to the fuel pump relay ignition positive voltage terminal verifies that the fuel pump relay ignition positive voltage circuit, the fuel pump positive voltage circuit, the fuel pump and fuel ground are all OK.

8. This step checks for an open ground circuit.

17. Replacement VCMs must be reprogrammed. Refer to the latest Techline information for programming procedures.

18. This step checks the fuel pump ground circuit on the fuel tank side of the body harness connector only. If the fuel pump ground circuit is OK, then the fuel pump positive voltage circuit or the fuel pump ground circuit in the fuel tank harness or the fuel pump itself is malfunctioning.

21. This test will determine if a short to ground on the fuel pump positive voltage circuit caused the fuse to open. To prevent mis-diagnosis, be sure the fuel pump harness is disconnected before the test.

 

[longstand]

I had a Question about flashing security light? maybe it has something todo with that. BUT I LOST remote. Can i just bypass this security lock. I hear there is somekind of a factory passlock. I have read it from here http://www.tahoeyukonforum.com/forum/showthread.php?t=38782&highlight=flashing+security+light+WILL+STOP+FUEL+PUMP

When my Car is OFF. the Light is ON

When I turn the Key. there is NO Light.

Also. There is 5 PIN on the FUEL PUMP Relay. Is there a Way to just connect two pin from them pin on the 5 pin HOLE to Manually Start the Fuel Pump "HOT WIRE". JUST TO SEE if it squirt FUEL?

I don't have a Scan Tool which turn on a Fuel pump.. I have a Torque OB2 Reader on my Android Phone

 

[SunlitComet]

it sounds like passlock is working normally as your light goes off when you turn the key as it should. it is when it stays on while driving or just flashes during start that you have a problem. to do the jump you need to short the two terminals i marked s on the block i pictured out below where the fuel pump relay goes. do not put anything in the ones marked with an o.


s*****s
******
o**o**o

 

[longstand]

I have try to short the two hole with engine TURN ON and/or TURN OFF

I did not see any fuel squirt out!!! Which mean its a 100% percent Fuel Pump...???

Your Image Instruction which you have attached keep changing!!

and as for your instruction "make sure the ground wire from pump to frame rail near by was not damaged" I dont remember Connecting any Ground . from what i remember. I put the Fuel pump Assembly in and snap Wire Connects and Fuel Pipe. That was all! and it worked

Thank you SunLitComet!! YOUR THE MAN!!. How do you know all this!! just curios? does all your car break down LOL thats why you know all this!!!

 

[SunlitComet]

cant do anything about images sorry but at this point you may not need them. and yes i know it was just connectors put on, but like the power wire that is in the front that goes back to the pump, it also has a ground wire. the ground wire may have been damaged when moving everything around. disconnect pump connector and test for continuity between the black wire in connector if possible and nearby frame rail. you should see some minor resistance but it should not be open. the ground is #3 in the picture below.

Fuel Pump and Sender (Utility)

did the new pump have a connector like the one pictured below?






one other thing use a test light or meter and remove the fuse for the fuel pump. apply neg test lead to ground somewhere and put pos test lead on either one of the two terminal the fuse was sitting in. one of them should have power at all times regardless of key position.

---------- Post added at 08:21 PM ---------- Previous post was at 08:20 PM ----------

oh i guess you probably forgot but i am an aircraft mechanic. i just do this for no reason at all i guess.

 

[longstand]

aircraft mechanic WELL,, this explains why your so good on giving instruction and smart enough to give instruction to a person of my english level. haha

Well I'm going to try that instruction!!. I REALLY REALLY HOPE its just GROUND!! and I REALY REALLY hope i dont need to drop the tank to test it.

and NO my fuel pump did not come with that kind of connection. it was a snap on


Also. Instead of dropping the Fuel tank to reach #3 "Ground on the picture" Why can i just trace the wire which is on the side of the Frame and Find the ground and GROUND That to the frame or do the test you wanted me too? What do you think? The ground should be Black, like most ground is..

 

[SunlitComet]

they are all snap on. i just ask because there were design improvements to the pump assembly over the years and the electrical connector was one of them. there were issues with damaged wiring or pumps constantly burning out so the connector went from a square one to an inline one.

just want to make sure you are not suffering from that.

the reason why i say test at the connector to a ground is because there is some wire you can not see unless unplugged and the connector it self maybe damaged.by removing it you can test the entire length of wire electrically to isolate it as/as not a cause. do what you can but if you can prove that power is at the under hood block and that the frame ground point is good you may not have a choice but to drop the tank to do further testing.

 

[longstand]

Mr. SunlitComet.. I got the fuel pump to PUMP again!!

I have drop the fuel tank just to make sure everything was connected properly.

Fuel Pump was not pumping because of GROUNDING issue on the frame.
I grind the frame Shiny and put everything back. now its Pumps fuel. without any issue

Now the TIMING and Distributor needs to be set

I will upload a Picture of the truck on a new thread..

 

[SunlitComet]

remeber you are just zeroing the distributor to the crankshaft. timing is controlled by the computer. in fact unless it is acting up and you get the p1345 code leave it for now if you want.

---------- Post added at 08:22 PM ---------- Previous post was at 08:20 PM ----------

dont forget to paint over the area you cleaned up after everything is together again to prevent future corrosion contamination on that ground