2015 Hesitation when cold start

I just purchased a 2015 TRD pro with 74,000 miles (118,000kms). After two cold starts I’ve noticed that there is a hesitation and a bit of a sputter after a longer than normal roll over. The starter itself seems very strong, not slow. After it has been running for a short period of time it fires right up with no problem at all.

I’m thinking it could be the fuel pump not holding residual pressure after a long sit. I’ve looked at a few forum threads and found that I’m not alone with this issue. Has anyone else who has solved this issue ever actually diagnosed it? I’m hoping it’s just the check valve on the pump, as this would be a very minor issue and would not need immediate attention.

My current next steps will be to prime the fuel pump before my next few cold starts just to make sure the problem is the fuel pump. May also run a batch of sea foam through it. Voltmeter seems to be in the correct spot before and after starting so I doubt this is a battery/alternator issue. However, I’m open to suggestions.

My only other question is if this is more common on flex fuel trucks. I live in Canada where flex fuel is much less common. I bought this truck off a guy who had originally bought it from the US with 5,000 miles on it. I highly doubt that he ever used flex fuel but it’s possible that the original American owner may have used some for the first leg of its life.

 

Update. Just started it this morning and it rolled over until it quit on its own. Then rolled over again for about 2 seconds before it started. Issue is worse than I thought.

 

With things starting to cool off it could be a failing battery starting to show its age. I see you tested the volts. Have you performed a load test?

 

I just load tested it. Failed. Showing 12.4 volts though. Will get a new battery but I doubt it will solve issue.

 

Sounds like an old battery loosing its CCA capacity , change it for new one , whats the date on the batery, they usually have a sticker

 

The battery is about 18 months old. It’s 840CCA. Failed 900 test, passed 800 test. So it’s lost a bit of its CCA capacity but it’s not terrible. I will replace it anyway but I don’t see how that small difference could cause this issue. I read that sometimes flex fuel engines need a remap every now and then. Wondering if that’s a good next step if a new battery doesn’t work.

 

Definitely an issue with some flex fuel trucks.