So, mine comes in solid when I turn the ignition to "ON". So it isn't likely a passlock issue.

 

I swapped the relay with the windshield wiper relay (which is identical), Windshield wipers still work.

As for continuity, I will take my multimeter and check the continuity at the relay. Wouldn't I need a long wire to go all the way back to the pump to check this?

There is also a fuel pump fuse.

How about I check voltage at the pump relay and fuse while I am turning the motor over? Should be 12V right? That way it would make sure that I am actually voltage to the pump.

Update: I just went out to do some of this stuff. I was able to confirm that there is no fuel pressure at the fuel rail. I did this by just pressing in on the little needle inside the schrader valve while . I was originally hoping to connect to this fitting to read fuel pressure with a gauge and fittings that a friend had, however his fittings did not match up. But my crude method works since its not low pressure, but rather zero pressure.

Not much is accessible at the pump (electrically speaking). I got under the middle of the car to confirm that the one noise I hear when the ignition is switched to ON is in fact NOT the fuel pump. Then I checked the voltage at the Fuel Pump fuse (not the relay... too confusing) under the following conditions.
Ignition OFF: Nothing (voltage bouncing around 0 just as if not connected)
Ignition ON: 31mV (steady) for about 5 seconds then back to nothing
Ignition START: around 28mV for the duration of the start attempt (10 seconds or so).
I think I should have expected a much higher number her, but the fact that it changed state makes me believe it is an electrical problem with the pump. Could be some type of short or a loose wire back there I guess. I won't be able to tell until I drop the tank.

So I am thinking I have enough info to just buy the fuel pump and go do it. I am going for one on autopartstomorrow.com for $317. It is an AC Delco MU1473 - Free next day shipping (Although this probably means Tuesday)
Edit: After realizing that the website charged tax, I went with Amazon.com, which was just a bit cheaper even after paying and extra $4 for overnight shipping. But if I didn't have the Prime membership, I would have gone w/ the former.

 

i should give up,you are not thinking. go slow,,,

picture a wire from the fuse to one side of the pump motor,got that?
think.

the other side of the motor has a wire that is grounded at the crossmember.

so the wire from the fuse goes to the motor , thru it to a wire to ground.
if you check resistance from the pump side of the fuse to ground you will read the motor resistance,(pull the fuse!). you dont want volts on you ohm meter.
if its open,something is open,wire,connector,motor.

just keep it simple.

you really should be looking at the wiring diagram. ive said it a million times. you can download the manual for 10 bucks,not a 2010,maybe a 09,definetly an 07.
all the same wiring.

 

You haven't wasted any money? So far you've taken it to a mechanic who can't tell you what's wrong with it. Good mechanic there, money well spent. If he can't even diagnose a fuel pump failure, which shouldn't take more than an hours diagnostic time, he probably shouldn't even be looking at it in the first place.

 

Actually ive seen allot of wake **** when it comes to cars and repairs.
And as stated fuel - air - spark.
My other post covered crank, cam, maf, tb.
I brought these up for good reason.
From reading ive done the maf & tb have a tendancy to get very dirty.
Following this line of thought to conclusion I would reason a dirty fuel delivery, with lack of air would indeed keep my truck not runnig. The injectors will not fire and the pump will not pump if certain fail safe checks by the computer on not met.
Crank sensor
Cam sensor
Maf
All have to be within proper values to allow the fuel pump to be engaged.
I would lean toward Docs reasoning on this one...
Test for proper ohms at the fuse.

Chris

jmho

 

@talusfan
I live in the country. You have to take what mechanics are available. That said, I do think I have a decent mechanic (I have tried a few in the area). The car was running fine while the mechanic was looking at it. Thats why he suspected the fuel pump (these can act up unpredictably). It wasn't until after I payed him (and after his hours of operation) that the car wouldn't start. He looked at it briefly with me after he had closed up for the weekend. We sprayed the carb cleaner into the intake and got to run momentarily, therby nailing down that it was a fuel delivery issue. All total, $95 for the tow and the intial diagnosis (which seems to have been correct). I would say these were unavoidable expenses, not money "wasted". Nothing compared to the money that would have been wasted having it towed the extra 25 miles to a dealer (at $4 per mile) and paying an extra $340 for parts + ~$200-400 for the installation charge. So anywhere between $540 to $840 extra.

Just because I own a "Hummer" does not mean that I am determined to waste money. I bought this Hummer for a few very good reasons.
1. I got a great deal on this car (the single owner had passed away) - $16,000 with 27k on it.
2. Our Chevy Equinox could not handle the rough private road that I live on.
3. I was considering other truck-like options (Tahoe, 4runner, etc...), which were all way more expensive.

So I guess I am a bit different from you, in that I don't have tons of money to burn, and that I am wary of dumping copious amounts of cash into a repair that does not have a clear success path.

 

Update: Last night when I was working on it with a friend, he convinced me to disconnect the battery and leave it sit overnight to see if that would clear any computer related faults in the "memory". I was in a hurry and left the back door unlocked with intentions of stopping back the next day to lock it. I stopped by the car to reconnect the battery and lock the back door (since I am fairly certain it only locks via an electrical signal). After I did that, I decided to try to start it (just for kicks). It started. I wasn't really expecting this, since I have been trying to start it off and on unsuccessfully for 3 days now. I am thinking this is just coincidence, but maybe not.

Bottom line: I took a bold leap and drove it the 5 miles home from the mechanic's somewhat public parking lot. Now it is home in my driveway (near all my tools) and I should be able to more effectively handle any unforeseen hangups. Plus, I will have an easier time convincing friends to assist me with free food and beverages available.

I am going to try what you said about checking the fuse resistance to ground. Which side of the fuse should I check? And which position should my ignition be in or does it matter? Also, I would have to assume that this will only give me answers if it is actaully having the issue. (Currently it starts and runs fine)
Maybe I will get some initial readings as a baseline to determine what is good. Although by the time it stops running again, my new fuel pump may be here. (eta - Tuesday)

Thanks for the input drtom. I will try this as soon as I can.

 

A suggestion I have is since you mentioned you connect to PCM via a Bluetooth connected phone, if it's an Android phone - there are tons of apps on the market that let you read more than just 4 parameters you mentioned.
Look into alOBD, Torque or do a general search in the App Store (Play) for OBDII.

OBDII Generic Mode 1 parameter readouts do provide MAF (to check sensor operation), RPM (to check crank position sensor), Fuel Pressure readings needed for your no-start condition. Mode 7 provides information on pending codes - the ones that have been detected but not yet posted. Mode 06 (if one available for your vehicle) may provide operational data on the fuel pump, misfire rates, O2 sensors, etc. which may provide a clue as to the fuel mixture. Speaking of fuel mixture, if your long term fuel trim (also Mode 01 PID) is a large positive number (> 15-20%) that means the computer is attempting to inject more fuel. Which means (provided all other sensors function correctly) the fuel pump cannot keep up and the injectors need to be held open longer to achieve the desired mixture.
As far as checking resistance and continuity this *may be* a dead end as current vehicles don't just have a motor in the fuel pump, but rather employ a digitally controlled fuel pump module which is controlled by PCM regulating pressure by commanding a particular duty cycle of the pump. Now, in addition to power wires, you can be looking at digital (or analog) signal wires both command and readback, etc.

One other idea is to check to see if all injectors are firing correctly, you can use either stethoscope or a screw driver to listen if each injector is "ticking" during operation and/or startup crank. Not sure about GM, but other vehicles active all injectors at once during startup mode until a pulse from Crank Position Sensor tells the PCM which cylinders should be fired, check to ensure all the injectors are firing when you crank...

Now, that you got your vehicle running, start it and listen how the fuel pump sounds when priming to make sure in the future you would "know" what noise to listen to.

If you can keep it running, use a graphing app (alOBD ScanGenPro) to graph fuel pressure, RPM and Load parameters at the same time. If the fuel pump is "tired" you'd see pressure drop at higher loads and/or RPMs, which would provide a clue into the "health" of the fuel pump. (But since you've already bought the pump, might as well replace it).

Just trying to help. (Don't be defensive...)

Thank you.

 

@abelouso
Thanks for the input. I actually was using Torque Pro ($5 application which has worked well for me on multiple vehicles). I mispoke when I stated the few things that I thought it read out. It does give me the MAF reading as well as O2 sensor voltages and a variety of other things. The application has the capability to report fuel pressure, but I don't think my H3 sends out that data (it doesn't show up as an active data point in my application). As I am sure you know, not all vehicles have the same data available at the OBD II port. Can anybody else tell me if they have been able to get fuel pressure data from a 2006 H3 computer? I got a variety of data that I logged and had sent to my email, but nothing that I found extremely useful in diagnosing this problem.

 

dont know abt 06