Starting Issue

I never had this issue until we had really cold weather last month. After my truck has been sitting for about 5 or more hours, when I start it it almost dies. It’ll crank just fine but as soon as it turns over, and I left off the key, it hesitates hard. RPM’s drop for a second, it sounds like it’s going to die then revs back up and is normal. It’ll start up completely normal for the rest of the day unless I let it sit for 5’ish or more hours then it does this all over again. The exhaust also smells completely different when it does this, almost like it’s running really rich. No CEL and no other issues other than this. It started when the temps got below freezing for 5 days (as low as -2 degrees) and I noticed it do this the first time when it was about 12 degrees outside. I’m thinking maybe battery going out or fuel pump going out. Idk why the cold would have anything to do with the fuel pump but I can see it killing the battery a bit.
What could this be?

 

Battery is dead.

 

My dumbass didn’t search before I started this thread but I came across TSB-0166-19.
https://static.nhtsa.gov/odi/tsbs/2019/MC-10170730-9999.pdf
Everyone who has had this happen to them that did the TSB fixed the problem. I called the dealership and talked to a service advisor but he clearly doesn’t know much. He’s going to get “assistance” from another guy and call me back. He said he couldn’t find that TSB anywhere but I did in <20 seconds. I’ll post back with results.

 

My truck has been in 3 times for starting issues when cold. They have changed the fuel pump, reflashed the ecm, and this last time told me to run a higher octane fuel. Said there was water in the fuel. I'm in Wisconsin and it was really cold when this was happening.

 

I had the same issue, and my first thought was battery so I replaced it because it was a little low in voltage. No fix. Finally I got a CEL today and had the reader hooked up, I got a P0300 which was a multiple cylinder misfire with P0308 which means cylinder 8 misfire. Most likely cause is supposed to be spark plugs. My truck has 109k on it with the original plugs so I changed them today. No fix. I was hoping a bad spark was causing no combustion in that cylinder and the plugs would fix it but it didn’t. I think I need a reflash, and maybe a new fuel pump. I’m pretty disappointed. I got a Toyota so I could have a reliability and this is an expensive fix. Please let me know if you fix it. Thanks

 

There is another active thread just like this. I personally think this symptom points to either fuel pump problem or a fuel pump relay issue.

Cold may affect the pump as with thermal contraction pump clearance opens up and it isn't very efficient.

 

I have the same issue with my 17 only 40k miles! I called dealer and he said I don't have any recalls...I said well I'm looking at the TSB and my VIN falls into it and I have all the symptoms. they hung up on me. I'll be printing it out and walking it into the dealer this week.

 

run some heat through the tank? good info thanks...

 

This is only in relation to FFV vehicles?

 

Yes

 

@dla500 Any luck with the dealership? I'm having the same problem with my 16 with 72k miles. San Marcos Toyota looked at my Tundra on Saturday, said it was low pressure from Fuel Pump. My VIN is on the TSB also, going to push to get it replaced with TSB. I handed them a copy of TSB 166-19...they said "master tech said mine wasn't on recall". I told him this is not a recall, it's a TSB. Service advisor says he will look into this week. They are going to order the FP anyway, while we work out the details on billing. I have extended warranty also, so worst case is $200 deductible. Much rather pay $0 since all symptoms relate to TSB.