05 Yukon Ocassionally Won't start...just cranks.

[Chevynut08]

i have a 2005 yukon slt with autoride. One day it decided not to start but only crank. i beat on the fuel tank in hopes to rattle the pump but no success. the truck sat for a couple days before i could get it towed. when i showed up to meet the tow truck it fired right up like nothing happened.

it happened again a couple weeks later at my work. i figured i probly cant fix it if its not broken so i kept driving it. That time at work i pulled off the intake tube from the throttle body and sprayed a little starting fluid just to see if it would fire and it did for a second. So then i beat on the tank again while someone cranked it and it started but i dont know if it was just a coincidense or not. the truck sat for about 12 hours while i was working that day. i didnt specifically check the spark plugs nor the fuel supply. but it drives perfectly fine when it runs.

it wouldn't start for a 3rd time just before christmas and had it towed home. the battery died from trying to start it plus being so cold. i just charged it up this past sunday and it started right up. seems like after it sits for a little it starts right up. i haven't really checked anything yet, as i'm not sure where to start. Thank you sooo much for any advice!

 

[Tonyrodz]

I'd check the fuel pressure, then go from there. Do you hear the fuel pump turn on when you turn the key?

 

[oldchev]

I just did a write up on this forum on another post.
I had the same (sounds the same) issue. My fuel pump was dying. When running the pressure was 54-55 psi. What it was doing was stopping and restarting while driving. I had a DTC of P0171 and P0174 (fuel trim lean). Eventually it quit at the hamburger place.
If you are not running and waiting for the tow truck (like me) or its just not running, look at your fuse box under the hood. Locate the Fuel Pump relay. Open your window and close the door. Turn the key to on. after the chimes stop hit the starter (don't attempt to start it just tap the solenoid) the quickly step to the FP relay. You should hear a click (one time) in less than 3 seconds. If it clicks the circuit is good. I don't think you can hear the pump running at least I can't. I don't like to wait and see or bang on the tank or whatever...I changed out the Fuel Pump.

 

[rockola1971]

I just did a write up on this forum on another post.
I had the same (sounds the same) issue. My fuel pump was dying. When running the pressure was 54-55 psi. What it was doing was stopping and restarting while driving. I had a DTC of P0171 and P0174 (fuel trim lean). Eventually it quit at the hamburger place.
If you are not running and waiting for the tow truck (like me) or its just not running, look at your fuse box under the hood. Locate the Fuel Pump relay. Open your window and close the door. Turn the key to on. after the chimes stop hit the starter (don't attempt to start it just tap the solenoid) the quickly step to the FP relay. You should hear a click (one time) in less than 3 seconds. If it clicks the circuit is good. I don't think you can hear the pump running at least I can't. I don't like to wait and see or bang on the tank or whatever...I changed out the Fuel Pump.

Just because the relay clicks does NOT mean it is good. The click just tells you that the signal to the relay coil is there and the relay closed its normally closed contacts. The only way to tell if those normally closed contacts are electrically any good is to measure the output with a voltmeter. If your fuel pump fuse is open (blown) then the relay clicking (closing its contacts) is meaningless since there will be no supply voltage available to go across the closed contacts to the fuel pump.

 

[Chevynut08]

Well it runs right now but for how long i don't know. I've never had any issues while driving except for at a red light it sputtered like twice and that was it and continued to drive good. Obviously i don't really wanna drive it bc i don't wanna have it towed again. Is it possible to check any of this stuff while it works fine? If i take it to a shop could they plug it in to see whats wrong? The only error messages i have is for the tire monitors bc of the rims, air bag message, and service ride control...i don't believe any of those would have an effect on whats happening.

 

[Tonyrodz]

Not saying this is your issue, but my express van with the vortec motor would do that occasionally, and it just got worse. The final straw was when I burned out two starters within minutes of each other, cranking it so much. Turned out to be the pcm. So far it's been a few weeks and it's still good.

 

[rockola1971]

Well it runs right now but for how long i don't know. I've never had any issues while driving except for at a red light it sputtered like twice and that was it and continued to drive good. Obviously i don't really wanna drive it bc i don't wanna have it towed again. Is it possible to check any of this stuff while it works fine? If i take it to a shop could they plug it in to see whats wrong? The only error messages i have is for the tire monitors bc of the rims, air bag message, and service ride control...i don't believe any of those would have an effect on whats happening.

Its hard to troubleshoot something that isnt currently broken.

 

[oldchev]

I'm just sayin' yours sounds similar to mine. The only way I can think of checking this is a fuel pressure guage that you can monitor while driving to verify pressure on next stumble or stall. Sounds awkward, yes. Probably won't happen in your garage or driveway.
Should you choose to replace the fuel pump, dropping the tank is no joy but short of removing seat and cutting the floor...
Keep the forum posted.

 

[retiredsparky]

You can install a temporary fuel pressure gauge in the rubber hose that feeds the injectors. You would need a brass tee with barb fittings to do this. Run the fuel hose out the front and tie the gauge to the wipers so that you can see it while driving.

Your symptoms are typical for a failing fuel pump.

If you replace the fuel pump, the fuel pump warranty requires replacing the strainer as well.

Larry

 

[Chevynut08]

Thanks for all the input guys I really appreciate it! Here's what happening as of right now: The other day my friend came over with his OBD II scanner to see if it was giving any codes but the battery was dead. I had high hopes that magically after i charged the battery back up it might give me something but it came up no codes as i figured. Not even with the tire moniter, air bag, and service stability messages on. Not to mention now the truck wont start again. I don't hear the pump running but i'm not sure i ever did even tho i was never listening for it while everything was normal. I know some vehicles the pump is quite loud. I put a new fuel pump relay in and still nothing. Im about to put it in the shop because i'm afraid to go through all the work for the pump and its something small and cheap. It's never stalled on me or shut off. Only stumbled the smallest bit a couple times at different red lights and random times. I've been ******* it on big hills and gettin on it on the highway here and there in between when it would run just to try and see if it would stumble but it never would. Just doesnt make sense that the only thing is that it wont start for it to be the fuel pump.