Starting Issues

[Breezy13x]

@swathdiver I’m not sure what the numbers are, I’ll try to get those soon.

@OR VietVet that might be the case it definitely is weird. And i just check the battery it’s around 4.5 years old so I guess it’s getting close to the end on that but still holds good charge and tested fine. And I checked the battery connections and they are tight and look to be pretty clean and I also checked the ground and it looks pretty good and free from corrode also.

I really appreciate all the help guys. I’m willing to look at all options! Haha

 

[OR VietVet]

You might try this: attach jumper cables between two vehicles and see if can duplicate the problem but that does not leave out the possibility of the battery or even the starter. Tests good how? Holds good charge, how do you know? These rigs are finnicky about batteries and cables and grounds. "Pretty clean" may not be good enough. I am only going by your description and to me it sounds like an interruption in the cranking rhythm and maybe not a spark, fuel or compression problem.

 

[Breezy13x]

@OR VietVet i can try that and it seems to start strong all the other stuff times besides when the issue starts and tests good on volt meter. And as far as “Pretty clean” to me is free from grime and corrosion with slight oxidation. And It definitely could interruption in the because that’s a great to discribe my issue. And with fuel pressure on the gauge is in spec and with new plugs and wires plus no misfire code I wouldn’t think it would be spark issue either. So I’m all for looking more into the cables as I know they could potentially corrode on the inside. What would be the correct way to test the wires? Is there a better way to test the battery or just take it in and get it load tested? Thanks again for the help!

 

[Jimmyy]

On my DD GM 3.8 I had a no start when hot. It would turn over just fine. As a shotgun approach I had the crank sensor replaced. So far so good. Pick up a spark tested and keep it in the truck so next time you can check for spark. HF has them under $10. Good luck.

 

[OR VietVet]

@OR VietVet i can try that and it seems to start strong all the other stuff times besides when the issue starts and tests good on volt meter. And as far as “Pretty clean” to me is free from grime and corrosion with slight oxidation. And It definitely could interruption in the because that’s a great to discribe my issue. And with fuel pressure on the gauge is in spec and with new plugs and wires plus no misfire code I wouldn’t think it would be spark issue either. So I’m all for looking more into the cables as I know they could potentially corrode on the inside. What would be the correct way to test the wires? Is there a better way to test the battery or just take it in and get it load tested? Thanks again for the help!

Check for voltage drop from one end of the positive brake cable to where it attaches at the starter. During cranking the voltage drop should be no more than 0.2 volts. While I am sure your battery and cables do not look as bad, this link may help you instead of me sitting here typing for a long time: https://www.hagerty.com/media/maintenance-and-tech/measuring-voltage-drop/

When I test a battery, I test it two ways. I make sure it is fully charged. To me that is 13.6 volts at least. I will load test it with battery cables on and with cables off. I want to compare the amount of resistance between the test leads and the cable ends and without the cable ends. Some say, no need, but I am very a-n-a-l about this stuff. I replaced all my cables and did the "Big Three" on my rig recently. Again, pics in my build thread. Many threads here about that and how to do it. The load test should hold above 9.6 volts for 15 seconds but I believe an AGM battery is different and unsure at this time what that would be. Google it or another member will chime in. At this point, with a battery 4.5 years old, I would throw a battery at it and check connections at the starter and do the drop tests and go from there. It may not be the problem but any time my personal battery gets close to 5 years old, it gets replaced. I believe in preventative maintenance instead of breakdown maintenance,

 

[Breezy13x]

So, I haven’t had time to do to much to the Tahoe, however I did clean the MAF sensor and it didn’t seem to help anything. Anyways this is my wife’s vehicle, she said if she hits the gas pedal during the time the issue starts happening it fires up. I haven’t had it happen to me and see how it responds while hitting the gas so not sure exactly how much it helps? So I don’t know if this could be somewhat useful information.

 

[OR VietVet]

That could be related to the "drive by wire" set up for the throttle, but I doubt it, and related to these:

https://www.rockauto.com/en/moreinfo.php?pk=3944205&cc=1441040&pt=5136&jsn=1171

More Information for GM GENUINE 25832864

 

[Breezy13x]

Hey, I’ve been crazy busy lately and haven’t had time to test anything on the Tahoe. With the 3 day weekend coming I’m ready to get to it. A few questions, if I clean the tb will I need a scanner to relearn it? Also, jimmy mentioned the crank position sensor fixing his hard got start made look into that. The symptoms seem spot on all way down to cel being on. Is there a way to test that? If I replaced it would I need to have a scanner to relearn it also? Thanks so much again for everyone’s help!

 

[donjetman]

I rag and spray clean the TBs on all our vehicles. No scanner or relearn is necessary.

 

[Breezy13x]

Here is my update, Still now check engine light, and i installed a new battery and the cables test good. (If i did it correctly) So i bought better scanner it did read some codes on the fuel pump module and it can read live data. her are my finding.

P0191_00 FRP sensor circuit performance
P0562_00 System Low Voltage
p2534_00 Ignition 1 switch circuit low voltage
P2635_00 Fuel Pump Low Performance

The only thing i really seen on the live data was going by the reference on the scanner was the Command air-fuel equivalence ratio value was low it was at 1. Could the low voltage issue possible be alternator? I have not had it checked yet. Also i still haven't clean the tb yet but will be doing that soon.