2012 Tundra Limited 4x4 intermittent increasing no crank issue

Blessings Tundras.Com Forum,
I have a 2012 Tundra Limited 4x4 with 261+K miles that has for the last 11/2 years given me an intermittent no crank issue. Once it does crank it starts right away, 13 months ago the dealership replaced the starter with an OEM which is what the previous starter was. less than a month the problem is back. The diagnose did not indicate no fault codes, I have replaced the starter relay, ignition switch and the problem is still there. I was not able in the past to duplicate the issue to further troubleshoot it. Here recently the problem is more common to the point I am no longer driving it. What I have been able to do is recognize is no power to the starter relay, I used my power probe to send 12v off the terminal going to the starter, and yes it started up. There are two Toyota dealerships (8-33 miles away) that have proven to be a bark above an inexperience shade tree wannabe automotive mechanic. I am a DAV with limited physical tolerance that limits my mobility to a degree of performing certain task of longevity (3-5min tops) with pain increasing as I push the envelope. If I am able to find a Wiring diagram/schematic of its entirety for a 2nd Gen Tundra, that will possibly increase my knowledge of where else to continue my troubleshooting. Definitely if any of you have experience this problem of know of a correct repair for this issue your mentioning of it would be greatly appreciated.

 

Is your truck a Flex Fuel truck?

 

Yes it is, I have not used any flex fuel.

 

If you have power and turn to start and it's no crank then it could be the trigger wire on starter vibrates loose. I had a no crank and wound up putting a glow of rtv on the trigger wire to prevent it from coming loose. Try reaching up under the starter heat shield and try moving it and try to start. This was my issue, worth a shot.

 

Thanks Mdl,
I will check it out.

 

So I'd still check your calculated fuel density value % via a bidirectional scan tool. On the flex fuel models it's know to climb gradually (typically over years) and cause these types of symptoms, even without the truck ever seeing E85.

A bidirectional scan tool can reset the value, but there's a specific relearn process that involves executing the reset at the gas station, then pumping in at least 3 gallons of gas, then driving the truck for 5 minutes at constant speed between 37-75 mph.

 

How does fuel density prevent the starter from spinning?

 

I don't know the mechanism, but many flex fuel owners have had starting issues, rough idles, and even misfires just over the fuel density % being too high. It's a low hanging fruit, and an easy potential cause to check off before sinking money and time into more difficult fixes

 

Thanks Red03 Taco for your reply, this issue is between the ignition switch and the starter relay. Fuel comes into play upon cranking the engine over.