2002 Yukon XL Not Starting Randomly

[treekillenyj]

Hello!

I bought a 2002 Yukon XL 5.3L about a year and a half ago, it's in good condition, has about 98K miles on it, and I haven't had any issues with it until a few months ago. I went to the store one day and when I got back to my vehicle it wouldn't start. The engine turned over but just wouldn't start, about 5 minutes later it started without an issue. I thought it was a one time issue and ignored it.

Well it happened again about 2 weeks later but after sitting for a night it still didn't start and had to have a friend tow me home, the weird thing is when I got back to my house it started just fine. So maybe something is lose and moving it jiggled it back in place?

I replaced the fuel filter since I read that it might be an issue, but afterwards it wouldn't start. I bought a fuel pressure gauge to check if it might be the fuel pump and it just happened to start, when it's running it's sitting at 46 psi idle and goes up to around 55 psi when I rev the engine, not sure if that would be an issue, I believe 55psi is what it should be at normally.

Something I noticed though is after sitting in between me replacing the fuel filter and fuel pump was the battery drained twice, the second time seems odd since I charged the battery and never tried starting it or turn it on. Another issue I noticed is after it's been idling for awhile when it's warmed up when I rev the engine the idle drops to the point where the engine sputters and the lights in the cab dim, but it doesn't die, so I'm wondering if it might be something electrical like the alternator or distributor cap? I hooked up a odb2 but there are no error codes, is there anything I can try to help narrow down the problem? Any help is appreciated!

 

[OR VietVet]

Welcome to the forum from Oregon. Please post up pics of inside and out of your rig.

If you can duplicate the no start problem then need to find what is not there. Sounds like fuel pressure is not a problem but may well be when problem is happening. May need to snake the fuel pressure gauge out back of the hood and tape to w/s and hope on a test drive and restart that you see a pressure problem. Maybe spark is gone intermittently. Plenty of you tube videos about intermittent no start and what was found. If you live in a rust belt state you could have problems related to the following info.

These rigs are notorious for ground problems. Many threads here about that. Here is a couple links about these types of problems:

https://www.fixmyoldride.com/Chevro...e7e5cd24ed24635&at_ab=per-2&at_pos=3&at_tot=4

https://www.tahoeyukonforum.com/threads/another-big-3-upgrade-with-questions.111196



We recommend that you put all your rig(s) info in your signature so we all don’t have to guess at year, make, model, engine size, trans, rear axle locker…….etc. While you may have posted pertinent info in your first post, you may forget to do it again and the info is needed by us anyway. Makes it way easier on all members that attempt to help, to have that info right up front. It is also recommended that you take a pic of your RPO codes, on the inside cover of the glove box, and post that image in your signature. All this info will greatly help those that will try to help with a problem.


If there is any other info, like upgrades, mods or recent mechanical/maintenance work done, that would be helpful in any post as well. Too many times a question is asked by the poster and after about 10 responses we find out that the poster has done recent work to attempt to fix the problem or work that was done that SEEMS not related to the problem.