Solved. New fuel pump, hard start.

[Mcneils10]

Hello everyone.
New here. I recently bought a 09 yukon denali with a blown up 6.2, I rebuilt it and but it back in. Now I'm a month down the road and I had to replace the pump due to rust at the assembly. After I replaced it I still had about 3-5 gallons of fuel in the tank, I tried to start and it started but took a few seconds probably around 5-10 seconds of cranking before it fired. I filled it to a half tank no issues but still take a few seconds of cranking to start or I have to try to start it a few times before it will fire. Any one know what could be going on? I'm checking the pressure in the morning.

 

[Fless]

Definitely check the fuel pressure to verify it's in spec.

When it's warmed up and running do a quick cam-crank correlation (CASE) procedure with a capable scanner, especially if either sensor was changed. Might not be your issue but with changes to the engine it might be the cause.

 

[Mcneils10]

I'll talk to my brother who tunes cars about the correlation sensor. Thank you for the advice.

 

[j91z28d1]

was it an oem pump?

I put a napa pump in my 96 and it was hard starting after that. I believe it wasn't holding fuel pressure correctly when it was off. if I clicked the key forward and paused for a second for it to build pressure. it would fire off cleanly every time like normal, if I didn't it would crank a few seconds longer and stumble a bit after the flare and then clean up.

I've just seen that newer gm now with the push button start will activate the fuel pump for a few seconds when you open the door to prime the system before cranking. I found that interesting.

 

[petethepug]

Welcome from SoCal. Nice pull on the L9H in the Denali. Pull the charcoal emission canister and verify it’s not spilling carbon pellets into the field system.

Only use OEM f/p or Bosch, preferably with the lifetime warranty. Best prices on rockauto and parts geek. Generic f/p can have you chasing ghosts, intermittent ones at that.

Check your crank position sensor. I learned the hard way they fail and cause hard starts without sending a code.

 

[rdezs]

As do aftermarket camshaft position sensors.....

 

[Mcneils10]

Solved. New cam sensor.

 

[rdezs]

Good to hear... Damn things are responsible for a lot of headaches!

 

[OR VietVet]

Welcome to the forum from Oregon.
You can edit thread title and add Solved, for others who read thread.

 

[petethepug]

Definitely what @OR VietVet says. Welcome from SoCal. Take the Win and edit the title to Solved. Crossing that off your list is a nice New Years treat for you.

 

[mattbta]

Good to hear... Damn things are responsible for a lot of headaches!

yup. my 2004 hates aftermarket sensors and did some goofy stuff with starting and cam sensor. put an oem in and back to normal.

 

[77mercury77]

Going to be doing my fuel pump soon. Anything else I should check or change while I have the tank out?

 

[petethepug]

I discovered these after I did my fuel system refresh or I would have installed one. It attaches to the bottom of the fuel pump and acts a a filter as well as a sump during cornering.

Looks like Holly is now marketing some of them as fuel sumps for $200 vs $20

https://www.holley.com/products/fuel_systems/fuel_pumps_regulators_and_filters/fuel_system_components_and_service/fuel_pump_accessories/parts/16-145?utm_term=&utm_campaign=Performance+Max+-+Holley+&utm_source=google&utm_medium=cpc&hsa_acc=7848552874&hsa_cam=21458109073&hsa_grp=&hsa_ad=&hsa_src=x&hsa_tgt=&hsa_kw=&hsa_mt=&hsa_net=adwords&hsa_ver=3&gad_source=1&gbraid=0AAAAAD1FzSqmtN7Pxu2IBWMmu2Ro6JBwn&gclid=EAIaIQobChMI5YOzyqbxigMVcJDuAR2CYjPiEAQYBSABEgJpF_D_BwE

 

[Fless]

Going to be doing my fuel pump soon. Anything else I should check or change while I have the tank out?

If you suspect a rusty top on your fuel tank, have a new lock ring handy just in case. Also, IIRC an evap line goes OVER the crossmember; be sure not to squish it by having it under the xmember.

 

[petethepug]

LOL empty gas tanks are much nicer to work on. 09-14 owners, Don’t have e85 in tank when you swap pumps. If you have to reset the fuel trim, it ONLY calibrates on petroleum, not e85.

 

[Fless]

@77mercury77

New fuel tank strap bolts? Dorman 55157.

 

[petethepug]

Touché

 

[j91z28d1]

Touché

View attachment 447758

70$? huh.

4 of those hooked up to the quick jack hydraulic pump. with turn tables on top could make for a nice home alignment rack.

 

[petethepug]

4 would turn it into a Black Widow. Not enough lateral stability. You’d really have to block out the front wheels because the parking brake is only in the rear.

Ah ¢rap! Looks like a scam site. It’s on the shunpuss website, not Costco. I should of caught that

 

[77mercury77]

Touché

View attachment 447758

Funny that you post the advert of the lift. I was planning on backing it up onto ramps to be able to pull out the tank. It think i only need to raise the truck about 8-10 inches to be able to drag the tank free past the lowest points. My other option is to jack the truck up from the rear (heh) and put the rear axel on jack stands. I have never lifted the truck from the rear diff; looks like that would damage the housing and the rear diff cover. If i have to do this because the ramps wont do where do i put the puck of a 3 ton floor jack on the differential? I got scrap 4x4s and 2x4s for cushion but i dont see a good location for a safe and clean lift point on the diff.