05 Tahoe rough idle and spark issue?

[Ben Solo]

How ya doin? I've got an 05 Tahoe that used to run great. But recently it's been having some issues starting and now it's running like I'm missing a cylinder or something.
When she starts, she's running perfect for about 2 minutes, then she would start idling rough, almost bogging. When I put it in drive and go at low rpm, it would be okay. But if I step on it then it would bog out a little bit.
I've changed plugs and wires. Changed coils. Changed throttle body also. But it still does the same thing. Just runs rough to the point I would have to make sure I've got someone ready to rescue me in case it stalled out.
Is there a fuel filter anywhere besides on the frame and in tank ?
Let me know if you got any suggestions. Greatly appreciated. Thanx

 

[OR VietVet]

Fuel pump assembly, in tank, contains the filter assembly, is a built in. Before any of this did you do a fuel pressure test?

 

[Fless]

It sounds like the issue happens when the fuel system goes into closed loop. Likely need to monitor short- and long-term fuel trims when starting and see what happens to them when the bogging starts. Also, like @OR VietVet noted, fuel pressure should be checked. When was the MAF sensor last cleaned or replaced?

You could also monitor individual cylinder misfires with a capable scanner.

Sounds like it needs a thorough evaluation / diag session. Stick to the basics: fuel, spark, air, compression.

 

[Ben Solo]

Found out that one of my spark plugs wires was arching off the blocc because of a rip in the insulation of the wire where it connects to the plug!! Well, for now that is. Now I've gotta leak or something on the hard brake line under the driver side. So I'm just going to cut it at the break spot and put them connecting things for the line. Ive gotta 03 Yukon I use for parts so hope it turns out. Wutchu think, Sound okay??
Well lmk. I appreciate the help, too.

 

[wjburken]

Now I've gotta leak or something on the hard brake line under the driver side. So I'm just going to cut it at the break spot and put them connecting things for the line.

Good find on the torn insulation.

What “connecting things” will you be using?

 

[OR VietVet]

I think he means a "compression fitting" and I am not a fan of those at all, but in a pinch, is a band aid to get to shop to fix correctly.

 

[wjburken]

I think he means a "compression fitting" and I am not a fan of those at all, but in a pinch, is a band aid to get to shop to fix correctly.

That’s what I was afraid of. As an engineer who has designed hydraulic systems, compression fittings are not a good idea, particularly in a critical system like braking.

 

[OR VietVet]

Cutting and flaring and installing a double sided flare fitting would be better but is still a patch. New solid line, IMO, is a must.

 

[SnowDrifter]

That’s what I was afraid of. As an engineer who has designed hydraulic systems, compression fittings are not a good idea, particularly in a critical system like braking.

agree

Op, I implore you.... Do NOT use a compression fitting

Those things are for like... 3 digit pressures. Not 4 digits that your brakes are under.

Like VietVet said, you had to union 2 lines, a double flare would be preferable. Interference mechanical fit, not just friction.

But like, honestly... Just throw some new lines in there. They aren't that bad to do. There are lots of places to be frugal, do an easy repair, etc on these vehicle. But your braking system is not the place.

And I gotta level with ya, this is one of those fixes that's going to be fine 99% of the time. Until it isn't. Jam the brakes hard in a full ABS stop? Watch it go pop. Not that there's ever a bad time to lose brakes.... But in the middle of a panic stop is probably at the bottom of the list. Whatcha stopping for? Kid darting across the street? Staring down the back of a semi when traffic stops unexpectedly? Cyclist get a stick through their spokes and fall off?

You can get a pre-bent stainless set off rock auto for ~100 bucks and you'll never have to worry about the things again. Hell, if you're in the Seattle area, I'll even help you with it. Not gonna have you out on the road risking yourself + others.