Won't start or idle without gas pedal

Morning all! After having my truck for several years mostly problem free it's finally decided to act up. Coming home from work last night I got behind someone running 15 in a 30, once they turned I downshifted and floored it (tired and sick of dealing with people all day nothing a good rev won't help lol). May have run 4k-4.5k maybe a bit more idk wasn't really paying attention this was less than a min driving like an idiot. Backed off and drove normal. Got behind another vehicle and when they started to turn off I slowed down and noticed the truck almost stalled out. Went a little further and started to turn into my driveway when it died, lost power steering and almost took out a fence and electric pole. Finally started up again and got into the drive way and immediately died again.

Now it will start only if I'm lightly pressing the gas, and will only keep running if pressing the gas. Doesn't really matter if it's barely pressing or not. But the second I let off it dies. Last night it would run perfectly normal sounding at any rpm but only as only as I was pressing the gas pedal.

No codes. Unhooked the battery for a few mins last night and didn't help. This morning tried to start to go to work and being cold I guess it was dying even quicker and sounded for lack of better term like it had a big exhaust leak. Was able to keep revving enough to move it and take another vehicle to work.

Any ideas? I searched for a long time last night and found several threads here and other places with people talking about dying after WOT but after a couple mins nearly all of them were back to normal. I did have this happen a year or so ago, had higher revs and as soon as I came back to idle it died and wouldn't start or idle for a few mins but then it was right back to normal.

I've seen comments of it being IAC, MAF, fuel pump, cat, brake booster, etc

Truck is 02 3.4 5spd


Thanks in advance, I'll try to check back and respond as I can today while at work til later tonight.

 

If it starts up if you lightly press on the Gas, I would start my checking the throttle body and give it a nice cleaning start ruling things. First rule out air, then gas

 

If you want to check if it's a Gas issue Crack open fule line that feeds the injectors to see if gas is flowing thru

 

When was your last fuel filter Change ?

When you put your foot into it the fuel filter just could no longer keep up.

Fuel pumps do get old and tired as well.

When was your air filter last changed ?? Needing to give the engine more air might mean it is restricted.

unhooking a fuel line is a very good way to meet the fire department.

 

Sounds like the idle air compensator to me… let me explain. The IAC is nothing more than a controlled air passage around the throttle plate. When you crank the motor over the PCM sends a signal to the IAC to open it slightly and let bypass air into the motor. Most IAC’s have electro magnets that “fight each other” and if you apply more voltage to one than the other the shuttle, the valve, the what ever they call the bit that blocks the air passages will either rotate more one direction or slide one direction more than the other. On some vehicles this is measured in degrees of dwell and can be monitored via a scan tool. Your observation that it takes a little bit of throttle to start it leads me to this. I would do the voltage checks and if it passes that, take it off and see if she just needs to be cleaned.

 

That to, what @Glamisman mention

 

Fuel filter fairly recent within a year and less than 10k. Toyota OEM
Same with air filter

Runs fine with revving or holding the pedal

I'm sure its due for a cleaning. I've never cleaned it since I've had the truck for the last 75k

I keep seeing that mentioned. Gonna have to see if I can find it in the dark tonight when I get home and try to pull it off and check it. Its just weird that the truck has been running seemingly perfect til I ran it at WOT last night for a short bit.

 

The only way to access the IAC is to remove the throttle body.

 

I would remove the throttle body check the IAC and give the throttle body a good cleaning

 

Issues crop up in weird ways but ya start at the IAC. On my ranger it would stick when everything warmed up and would want to stall the truck when you step on the clutch. Especially coming off of high rpms

 

Well that's wonderful. I've been putting off replacing valve cover gaskets cause I didn't want to dig in to all the mess up there lol

 

Well got home a little early from work and had a buddy that’s a mechanic on his way to help me look at it. Started right up and ran perfectly He looked in the throttle body and says it’s not too dirty, said to go ahead and clean it and see what happens the next few days.

Glad it seems to be running right now but I’m definitely not very trusting of it. Still gonna try to pull the throttle body and iac to clean them both good in a few days. Maybe I scared it when I was searching for other trucks on my lunch break today. (Definitely got major price shock on that)

 

Yep… got a call from a Buddy yesterday, his 05 Duramax was stolen and all they took was the automatic transmission (Allison 5 speed). The truck is totaled as the price of the trans and core exceeds the blue book. I told him buy it back and pay the piper as a replacement is $45k +

 

It’s insane. I looked at a 10-12 year old Nissan with 125k and they wanted 16k for it. Saw a Titan about the same age and it was almost 20k.