Weird thing happened today

2009 DCSB 6 cyl 4x4 347,500 miles. Never had any trouble with the truck with anything. Drive 90 miles to work today. Ran like a top as always. Fired it up and move it to get the sun at my back, killed it and sat with the radio playing for maybe 10 minutes. Fired it up to let the battery charge(I know but I hate dead batterys) for a few minutes. Sat the rest of the day til 5 in 109 degree heat. Went to fire it up, starts and dies. Cranks and no fire. Turn key all they off, then starts and dies. Repeat. All my buddies are saying fuel pump. I pull the cap off and the tank is pressured up. Open the hood and pull the leads off the battery for 10 minutes ish. Hook it back up, fires up but idling at about 300 rpm and pretty rough. Run down a dirt road a bit, running great. Kill it, fires right back up but still idling rough at 500 rpm. Turn on the a.c. And it kicks the idle up to 800 and smooths out. Runs like a top all 90 miles back. Idling good at stop signs and through town. Get back to the house, kill it, fires right back up like normal. I've put 150,000 on this truck and I don't know if the fuel pump has ever been changed.

Any ideas, maybe get the brain trust at orielys to pull the code?

 

Sounds like a good old vapor lock in the fuel line. I know it's not supposed to happen with FI, but things don't always go as the engineers expect them to.

 

Fuel pump wouldn't be my immediate thought on what's going on with it. Without actually checking for spark, inj. pulse, codes, etc it could be many things that were causing the start and die. Fuel pumps aren't usually an issue on these trucks.

 

Vapor lock was brought up too and my my first thought to be honest but like you said shouldn't happen on these new trucks.

 

Not saying it shouldn't saying it's not typical. Your description leads me to think of an issue with a sensor or idle control not really a fuel pump issue but it's gotta be acting up (more than likely) and you gotta know how to properly diagnose to find the real issue.

 

I should rephrase, you wouldn't think it would happen on these newer trucks but fuel is fuel and it all reacts to temperature the same. I'm good and troubleshooting and fixing my cars and trucks. The "maintenance required" light is on so I'm hoping it threw a code that will point me in the right direction on what to change out.

 

Ummmm maint required won't help you at all with troubleshooting other than it's time for an oil change . Throwing a code points you to a system or possibility you still have to know how to test the sensor etc to determine what actually failed and needs fixed

 

People that suggest vapor lock don't know what vapor lock is. Vapor lock is when gas in the fuel line gets heated by the exhaust pipe 3" away and boils the gas turning it into a vapor. The mechanically driven diaphragm pump tries to pull gas vapor and can't. It would be like trying to climb a rope with 1 arm and no legs.

Tacos have a motor driven pump submerged in gas. The truck would have to be on fire for all the gas around the pump to boil away. At that point, you have a lot more problems than the truck not running.

 

Well I just changed the oil and usually don't drive the truck to work anymore so it's no where near needing an oil change and the light came back on during the episode today. And no check engine light or anything else. I know my stuff with vehicles. All I'm looking for is a direction to go head in as far as getting it fixed quickly. I leave super early and get back late for work. Just trying to get a little head start from TW. Our mechanic has a badass snap on code reader but he was gone when this happened.

 

The truck doesn't know you changed the oil. You have to tell it.

 

Yes I don't think it was vapor lock either. I never even had that problem on my 70 Chevelle because I knew how to run the fuel hose to the carb. It was not but not enough to boil gas under the hood. It's gotta be a sensor I'm thinking.

 

I turned the light off when I changed the oil. I've been driving it all week with no maint required light on.

 

Well, that's weird then.

 

When you disconnect the battery for around 10 minutes doesn't that re-set the computer? Don't you need to drive it around some for the computer to re-learn? I thought a low and rough idle should be expected.

I'm pretty sure I read that around TW somewhere.

 

You are correct on that point after disconnecting the batt.

 

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Yes. That was the idea to see if it would work and it did. Still worries me though with the distance I go to work. It's gotta be something going bad and I want to fix it because I love the dependability of these trucks. I didn't know about the rough idle afterwards however.

 

It doesn't seem like it. Sorry if this seems offensive.

 

A weak battery can cause strange things. Maybe driving some finally brought it up enough for the systems to behave. I would stop by Autozone or Advanced and have them do a load test on the battery. Takes 30 seconds and is free

 

Ok here's the thing. I do know how to mechanic and trouble shoot. Being a Toyota that I've had zero problems with this will be my first time with this specific truck. I will figure it out quick and learn all about the system that is malfunctioning, I was just curious if someone had this happen to them before and I could narrow it down quickly I'm 41 years old and have been working on cars for most of my life. I'm pretty savvy and catch on quick. That being said, I'm no tech either, I hadn't had a check engine light or anything on this truck. So I'm not sure it's throwing a code of not. There are no lights on the dash at all except for the maint light. So I was unsure if that's just the general idiot light for codes or whatnot. Apparently not. And is it not odd that it came back on during this thing today?

 

The batt is about 3 years old now and seems strong but that's a good idea. The truck sits for most of the week this past year and a half. I'm a pipe welder\fabricator so I drive the rig truck every day until this week when we're basically just going in for hours. I do go home about every other week and zero problems on my 5 hour drive. I'm going to go ahead and drive it tomorrow and have the mechanic come check the battery and pull the codes and go from there. I'll update if anyone cares.