Starting issue

[Doubeleive]

I made sure to be prepared and took my time being picky. Still had to run for a clip nut for one strap that broke. Sprayed the pump and tank straps with bedliner, etc. I did it Saturday afternoon and Sunday morning no problem. I backed it up onto my ramps.

Also ran that baby so close to empty, it wouldn't start until I rolled it back onto flat ground. Lol

ya you want that thing to be on fumes, lol usually they right after a fill up

 

[swathdiver]

Is this a huge bear of a job in the garage on jack stands? I would most likely be attempting this solo.
Or better to have someone with a lift tackle it?

I've got lots of tools and several floor jacks and 4 stands but do not have those tools that easily disconnect those new to me style lines. They're on my list but maybe Harbor Freight will have them, O'Reilly or Autozone should.

Last time we looked, did we check the fuel pressure? I seem to think that we did but cannot remember.

 

[iamdub]

First time seeing this thread and @thompsoj22 said on the first page what I was leaning towards. What module controls the starter- PCM? BCM?

If it never happens when cold, I'm wondering if you have an intermittent open circuit in whatever tells the module to disengage the starter. At first, I understood it as the engine firing up like normal but the starter was still engaged. Then later it was said that it cranks for 5-6 seconds and doesn't start, but then cranks and starts just fine on the second try. Could it be that it's not a starter engagement control issue and it's not firing up so the computer keeps cranking it in an attempt to start it? Sometimes it just doesn't fire at all and other times it fires up almost right away, but it's sputtering as if it's getting too much fuel or not enough fuel so it doesn't reach the RPM the computer wants before it disengages the starter? It's been a long day so maybe I'm mixing up some details.

 

[dross99_si]

First time seeing this thread and @thompsoj22 said on the first page what I was leaning towards. What module controls the starter- PCM? BCM?

If it never happens when cold, I'm wondering if you have an intermittent open circuit in whatever tells the module to disengage the starter. At first, I understood it as the engine firing up like normal but the starter was still engaged. Then later it was said that it cranks for 5-6 seconds and doesn't start, but then cranks and starts just fine on the second try. It's been a long day so maybe I'm mixing up some details.

It's more like the cranks for 5-6 seconds and doesn't start, but then cranks and always starts on the second try, but with a sputter and very brief rough idle that normalizes.
Never happens on a cold start.

 

[dross99_si]

I've got lots of tools and several floor jacks and 4 stands but do not have those tools that easily disconnect those new to me style lines. They're on my list but maybe Harbor Freight will have them, O'Reilly or Autozone should.

Last time we looked, did we check the fuel pressure? I seem to think that we did but cannot remember.

No we never checked fuel pressure. We were trying to figure out the darn P0442.

 

[iamdub]

It's more like the cranks for 5-6 seconds and doesn't start, but then cranks and always starts on the second try, but with a sputter and very brief rough idle that normalizes.
Never happens on a cold start.

So now it seems those other symptoms are issues resulting from a root problem and are not the root problem itself.

Yeah, at this point I'm gonna jump on the fuel supply bandwagon. The symptoms are similar to a faulty prime valve (AKA "check valve"), except that issue happens pretty much ONLY during a cold start.

With the issue presenting after it's run for some time, I'm thinking a fuel pump failing when warm (intermittently).

 

[dross99_si]

So now it seems those other symptoms are issues resulting from a root problem and are not the root problem itself.

Yeah, at this point I'm gonna jump on the fuel supply bandwagon. The symptoms are similar to a faulty prime valve (AKA "check valve"), except that issue happens pretty much ONLY during a cold start.

With the issue presenting after it's run for some time, I'm thinking a fuel pump failing when warm (intermittently).

Thanks for your suggestions. So is there a definitive way to distinguish between a failing pump vs faulty injectors just by checking and/or monitoring fuel pressure during different conditions.

 

[iamdub]

Thanks for your suggestions. So is there a definitive way to distinguish between a failing pump vs faulty injectors just by checking and/or monitoring fuel pressure during different conditions.

Yes. This is what a full and proper fuel pressure test is for. It's why you watch the pressure gauge with Key On/Engine Off, Key On/Engine On, etc. The problem with you performing this test is that your symptoms don't present frequently at all. Everything may pass with flying colors but a few starts after you remove the gauge, it may act up.

 

[HiHoeSilver]

Yes. This is what a full and proper fuel pressure test is for. It's why you watch the pressure gauge with KO/EOff KO/EOn, etc. The problem with you performing a this test is that your symptoms don't present frequently at all. Everything may pass with flying colors but a few starts after you remove the gauge, it may act up.

Yup. But it sounds like it's pretty repeatable at this point. I'd get some baseline numbers cold (pressure at ko/eoff, see if it bleeds down, pressure at idle and driving). Then shut her down, and do it again warm. Ko/eoff might even be your answer right away at that point.

 

[iamdub]

Lol

I just realized that "KO/EO" could be read as "On" or "Off". Edited post to clarify.