No Start after Alarm is used

[Mikemustang289]

Having a weird issue with my 2000 Yukon Denali. Its the older body style with a 5.7 V8. The truck has been randomly not starting over the past few weeks. I was thinking the battery might be getting low or going bad. Yesterday it left me stranded in front of autozone (lucky for me) . I noticed that when I turn the key to the ON position I dont hear the fuel pump prime and when trying to start it will just crank as though its getting no fuel. I checked the fuel pump relay and it bench tests good, also bypassing the relay with a jumper turns the fuel pump on so I know the relay and pump are good. So while stuck at autozone and having no luck getting the engine to start I bought a battery and swapped it out. The battery that was in the truck was only putting out 12.3 volts. I put the battery in and it starts right up. I drove it around yesterday with no problems. Parked it last night and set the alarm. Today I try to start it and again the pump is not priming and it wont start. I disconnnected the battery for a few mins, reconnected it and it starts right up. I'm thinking now the issue has something to do with the alarm. I'm going to avoid locking the car with the key fob for now to see if the problem continues. Anyone have any idea what might be causing this issue?

 

[zomeizter]

Had a similar problem with mine, I resolved it by replacing the key and tumbler and performing the relearn procedure for the VATS.

 

[willxfs]

My 1998 2 door rig would occasionally do something similar a few years back. It would randomly not start for periods of time. Sometimes 30 minutes but sometimes longer. It ended up being the pic tail connector on the fuel pump. For a while I could get it to start by reaching up over the top of the tank and jiggling the wiring harness and connector. It progressively got worse and worse. After a ton of troubleshooting, I lowered the tank just enough to change out that connector and problem solved. Some new fuel pumps come with the new connector. Probably for this reason... Good luck and keep us posted on the problem.

 

[trevcda]

I had similar symptoms several years ago. It ended up being the fuel pump, which was a royal pain. But I haven't any trouble since. At least not with that. There's always something else.

 

[Mikemustang289]

Update: I don't drive the Yukon very much so the issue hasn't been resolved yet. It still will randomly not start. Sometimes it will work great for a week then randomly not want to start. The security light on the dash does not stay on, it will blink when I put the key in the on position then the light goes off like it should and it starts right up. No issues with the security light so I no longer think this is related to the VATS system.

One very odd thing that happens when it won't start: I'll put the key in the ignition and turn it to the on position, randomly the gas gauge needle will peg itself all the way to the far right past the full mark, when this happens I get a no start condition every time. If I put the key in and the gas gauge reads correctly it will start every time.

The fuel pump primes like it should. I've even tried bypassing the fuel pump relay to turn the fuel pump on manually and it still won't start, just cranks and cranks while the fuel pump is running. I know the fuel pump is working so either the injectors are not firing or the ignition is disabled when this happens.

Disconnecting the battery and reconnecting it after a few minutes will usually resolve the issue and I can start it up. I'm kind of at a loss at this point. I can't really find much info online.