Odd starting issue... any ideas?

[domoarigato]

Hey guys,

Recently I've been experiencing a weird starting problem in my 2011 Tahoe. When turning the vehicle over it cranks like there is no problems, but the second before the engine fires, there is a short hesitation/pause and then it starts right up.

Initially I thought the battery may have been at the end of its life cycle, so I replaced it with a brand new one.

This morning I went to start it, and it was doing the same thing again. I've noticed that it only exhibits this symptom when its been sitting for a few hours. If I run into the store and come back out, it will fire right up.

Any idea as to what it could be? Perhaps a dying starter? I just find it odd everything sounds normal until up to the final crank.

Open to any suggestions as to what to check / troubleshoot.

Thanks!

 

[Scooty]

Mine was doing the same thing...after starting the first time it would be fine the rest of the day. Next morning the same problem. I was told by a mechanic friend to clean my MAF sensor and while I was at it clean the throttle body. He told me to make sure to get the correct cleaners for both units. I did the cleaning on both and it starts like it's brand new....no problems since. This was just my experience but very easy to do.

 

[domoarigato]

Mine was doing the same thing...after starting the first time it would be fine the rest of the day. Next morning the same problem. I was told by a mechanic friend to clean my MAF sensor and while I was at it clean the throttle body. He told me to make sure to get the correct cleaners for both units. I did the cleaning on both and it starts like it's brand new....no problems since. This was just my experience but very easy to do.

Haven't even thought about the MAF sensor! Thank you for bringing it up. I have some MAF cleaner sitting around I'll give it a go!

 

[kbuskill]

Haven't even thought about the MAF sensor! Thank you for bringing it up. I have some MAF cleaner sitting around I'll give it a go!

Sounds like perhaps the fuel system is losing pressure when it sits for a while. Next time it sits overnight try priming the fuel system by cycling the key to run (not start) and back to off and back to run... do this 2 or 3 times before attempting to start and see if there is any noticeable difference.

 

[swathdiver]

Jake, what kind of fuel are you running in that truck? Sounds like a low octane issue from a cold start due to cold weather. What has the weather been like where you live?

 

[02Lightning]

Jake, what kind of fuel are you running in that truck? Sounds like a low octane issue from a cold start due to cold weather. What has the weather been like where you live?

I think you have that backwards.
https://www.motoring.com.au/myth-busting-high-octane-fuel-will-make-a-car-faster-7513/

 

[domoarigato]

Hey guys, thank you for all the suggestions so far.

Here is a video that better shows what is going on, note the slight hang at 500rpms when turning it over (sorry weird link not sure why, it links to youtube)

https://r5---sn-5ualdn7s.googlevideo.com/videoplayback?mt=1516296748&initcwndbps=618750&ei=iNpgWo_dHIiHqgWr4biADQ&signature=CC3A13ED8B5FE61EB6001506E68E671FB167CFEA.6BA1CBE2F78F2693D8C46FA9C764B3EE4C210137&ratebypass=yes&dur=9.589&key=yt6&lmt=1516295843458255&expire=1516318440&sparams=dur,ei,id,initcwndbps,ip,ipbits,itag,lmt,mime,mm,mn,ms,mv,pl,ratebypass,requiressl,source,expire&ipbits=0&mm=31&mn=sn-5ualdn7s&id=o-ANk_ZIj_Ij89rd98zMzPAz9XVQvUlehfQcxH9noodYOS&mime=video/mp4&pl=23&source=youtube&mv=m&itag=22&ms=au&ip=66.64.166.178&requiressl=yes

Here was a before and after of my MAF, but it didnt fix it much cleaner and better throttle response now though!




As for fuel, I'm running just regular 89 (diablosport 89 tune as well)

 

[swathdiver]

I think you have that backwards.
https://www.motoring.com.au/myth-busting-high-octane-fuel-will-make-a-car-faster-7513/

Greg, real world experience proves otherwise. Do it yourself and see, the guy is a fool.

Here is a video that better shows what is going on, note the slight hang at 500rpms when turning it over

Jake, I think that is a hanging starter or starter related. While no fan of low octane fuels, I do not think that that is your problem in this instance.

 

[kbuskill]

Hey guys, thank you for all the suggestions so far.

Here is a video that better shows what is going on, note the slight hang at 500rpms when turning it over (sorry weird link not sure why, it links to youtube)

https://r5---sn-5ualdn7s.googlevideo.com/videoplayback?mt=1516296748&initcwndbps=618750&ei=iNpgWo_dHIiHqgWr4biADQ&signature=CC3A13ED8B5FE61EB6001506E68E671FB167CFEA.6BA1CBE2F78F2693D8C46FA9C764B3EE4C210137&ratebypass=yes&dur=9.589&key=yt6&lmt=1516295843458255&expire=1516318440&sparams=dur,ei,id,initcwndbps,ip,ipbits,itag,lmt,mime,mm,mn,ms,mv,pl,ratebypass,requiressl,source,expire&ipbits=0&mm=31&mn=sn-5ualdn7s&id=o-ANk_ZIj_Ij89rd98zMzPAz9XVQvUlehfQcxH9noodYOS&mime=video/mp4&pl=23&source=youtube&mv=m&itag=22&ms=au&ip=66.64.166.178&requiressl=yes

Here was a before and after of my MAF, but it didnt fix it much cleaner and better throttle response now though!




As for fuel, I'm running just regular 89 (diablosport 89 tune as well)

Out of curiosity... where did you get an 89 octane tune? Is it like a custom "Diablew" tune?

My Diablo I2 only has the following "canned" tunes available.

MPG tune
87 tune
91 tune
93 tune

I just flashed the 91 tune for the first time the other day. I cut 2 degrees of timing out at WOT to alleviate a little spark knock that I was getting with 89 octane but I also topped off with a half tank of 93 octane so not sure which one helped.

 

[Doubeleive]

running some injector cleaner may help I think some other people had a same or similar problem on here and after running some injector cleaner (couple bottles a tank) problem went away, I have like 3 cases of that stuff sitting around so I throw it in often myself.