Tundra doesnt start in the heat

Live in Southern Arizona. It gets hot here from time to time. Replaced the charcoal canister with a toyota charcoal canister. Ever since then, anytime the temperature gets above about 90 degrees, the truck wont start in the afternoon. Cranks up fine in the morning, and later in the evening, but getting it to start during the heat of the day or mid afternoon is about a 10 minute process(makes me think vapor lock). I've looked into it a little and have narrowed it down to maybe fuel filter, fuel pump, charcoal canister, or vacuum leak. Any help would be appreciated. Thanks

 

Have you had the battery tested? Heat and batteries don’t mix well...

 

Battery has been tested. A new battery was put in about a year ago.

 

I guess it’s possible that the new charcoal canister is failing. Do you top off when you get fuel or do you just let the pump shut down and call it good enough?

 

As soon as the pump shuts off I stop. I dont add anything extra

 

Have you checked/replaced battery cables? When cables are hot, resistance increases and if there is any corrosion, it could be enough resistance to cause it to not have enough power. I dealt with that issue on my '40 Chrysler when I reused a starter cable on the big block I put in it.

 

So when it doesn’t start in the heat of the day, is it turning over like a champ just no start? Or does it sound sluggish?

 

It has a great crank. Sounds like it tries to start but there is no fuel, which leads me to believe its vapor locking or there is a leak somewhere in the fuel system. I will sit there and pump the gas pedal a few times and crank and nothing. After doing this about 4 or 5 times it will sluggishly turnover and then die and then roars to life on the next turn of the key.

 

I have not checked the cables at all. Never thought about it because it only does it during the heat of the day during summer. But I would think if it was cables or battery it would happen everytime, not just during the afternoon on hot days

 

Did you ever figure this out?
I'm having the same issue. In NM (currently about 100 degrees). First start of the day it starts fine. I'll run it around town, if I let it sit for an hour, it will crank over for 3-4 seconds, then have a weak start...and then it runs fine. If I kill it, and start it immediately it starts right up.

Frustrating. I have a new: fuel pump, filter, fuel pump resistor, and fuel injection pressure damper. Mechanic couldn't replicate the problem...its back a the shop now. Would love to know if you figured it out.

2000 Tundra 4.7 extended cab 4x4

 

I am having this same issue in Tennessee during summer months. Anytime 90 or above truck doesn't want to start. Once i get it started if I turn my truck off then back on again immediately it starts fine. But anytime it is left for longer periods " cold start" during summer days it does not want to turn over.

 

As in, you turn the key forward and everything goes dead, or it just doesn't crank? Or it cranks and it doesn't fire? Just curious.

I wonder if @realtormarcos ever figured this one out.

 

Sounds like a fuel relay issue... I've had similar issues with my 1UZ... summer times are sluggish starts, starts then dies, turns over with no start and stalling.. early mornings were good starts but over time it spread to the mornings as well.. swapped thay relay out, problem solved.

 

Cranks good but does not fire. Sometimes cranks for 5 seconds or more before firing. Only does this when the truck has sat and it is very hot outside. Once it starts and say I go inside the store and come back out it starts just fine. Typically it is 90 + degrees when it does this and has sat for 4 to 5 hours. I'm thinking fuel pump. Considering it's the original with 275k miles.

 

You should be able to check the fuel pressure with a loaner kit from one of the auto stores to rule that out. Actron makes one with the banjo bolt to schrader valve adapter you'll need to tap the fuel rail.

I'd probably replace the fuel filter before the fuel pump.

 

Could also be the relay or pump. Curious, when it actually fires up, if you jump out right away and smell the exhaust does it smell overly rich?

 

It’s a long shot but did you ever figure this out?

 

Both haven't been seen since about a week after they posted. Never had a similar issue when I lived in Mesa, AZ. I would start in fuses and then relays, see if you have issues there, another issue might be the fuel resistor, or fuel ECU located near the gas tank under the bed.

 

This is also the 1st gen (2000-2006) subforum, but I see a 2021 linked in your profile. If you're dealing with your 2021, you may not find what you need in this forum, dealing with 15-21 year older trucks...