Tacoma 4.0L hard to start when warm

https://youtu.be/Bl1o2B90ntg

Didn't seem to fix it. I'll redo fuel pressure test and see if I'm still losing pressure before checking anything else

 

So frustrating. I'm hoping that the injectors is still leaking, I marked which one in was and placed it on the front passenger cylinder, I can swap it out without pulling the entire rail, if my pressure is still dropping

 

What side is it on and what number in order of counting up one, two, three?

 

Passenger side closest to the radiator. I don't know where it was originally, but I moved it there for easy access if it wasn't fixed

 

Really...you call that a hard start! A 1-2 second crank to start is nothing. Saw another utube video of a supposedly hard start...just like yours! And he is going thru pains to correct it also. Doesnt seem worth the effort for the minimal gain.

 

Well, that wasn't the hardest start I have had. I've had it take much longer. I've also had it start and immediately die. And I don't mind putting in the time or effort to have my vehicle perform as intended

 

That didn't seem like too bad of a hot start. Was it worse before the cleaning?

You do know you pressurized the fuel system as soon as you turned on the key. You had the key on for 30+ seconds before engaging the starter.

Can you retest and just jump in the truck and start the truck in the normal fashion?

 

Have you smelled the exhaust when doing one of these hot starts? It should rally smell like gas if it is a leaking injector.

 

Yeah, I had the key on just because I was talking. I didn't anticipate talking that much actually. It definitely started better that before, but still longer than a cold start. I'll be able to tell more tomorrow after running around all day.

I have smelled the exhaust. It has a sweet smell at times, and a gas smell sometimes. My nose sucks though, I should probably get my bloodhound of a wife out there...

I'm going to try to repeat a fuel pressure test in the next couple of days and see where I stand.

Also, according the the Haynes manual, the fuel pump does not come on with the key "on", it runs immediately when the key turns to start. But is this not the case?

 

That makes no sense. You don't run with the starter engaged. Key on has to energize the FP.

 

The manual could be wrong (it has been about other things) and it doesn't make sense to me either as every vehicle I've ever seen the pump comes on and primes the system for a few seconds. Maybe someone more familiar with chime in.

I will say, I can't hear my pump come on with the key in on, I've had someone turn it to on and listened underneath, and at the fuel door. So if it is supposed to that could be the cause of my issue.

 

I think the confusion stems from the injectors.

The injectors don't energize until the crank shaft positioned registers several revolutions of the crank. This is why every Toyota seems to take a long time to start.

 

Everything I can find online, which is limited and mostly people posting on message boards states the pump doesn't run until the ECU detects the starter has been engaged.

I'm thoroughly confused now, because maybe my problem has just been my pump isn't coming in early enough...

 

I've read this as well, but it can't be right. You can hear the pump run with the engine off and the key on.

My 1st gen pump runs with the key on, I can hear it cycle. This how I found out I had leaky injectors.

I left the key on so I could have lunch with the wife with the radio softly playing. I could hear the pump cycling every 2-3 minutes. A half hour later when we finished our lunch and I tried to start the truck, I got the dreaded hard, hot start scenario.

Try it with your 2nd gen. With a warm engine just turned off, turn the key to run and sit and listen for the pump to cycle. If you have multiple cycles and 15 minutes later the truck struggles to start, you could have leaky injectors.

I want to see this issue put to bed. Keep up the fight.

 

That is because you have a first gen. Not only did Toyota switch to CAN communication, but so did their methodology of starting the truck as a whole. As I previously mentioned, these are no longer operating in a similar fashion to most of the GM cars out there anymore. This pump energizes the moment you start cranking.

To the guy talking about the OP bitching and hawing about a long start, it IS a big deal. Because if this issue is not nipped in the bud right now the issue will only amplify over time, how much more time is anyone's guess, but it is not something you want to worry about when you are hundreds or even thousands of miles away from home.

 

This is NOT the cause of your issue. This behavior at key on engine off is normal.

 

Thanks, that's what I thought. Just needed some confirmation.

I should be able to run another pressure test tomorrow so hopefully I'll be able to gain some more info. I'm still hoping that it is injectors leaking.

 

Fuel pressure still seems to be dropping. I pulled the passenger side I of the rail while it was under pressure and didnt see any injectors on that side leaking so looks like I'll have to pull the whole rail again. I've gone from 41 psi running to 25 psi after 12 minutes.

Also noticed my throttle body wasn't opening at about 3k RPM. Anybody know how open is should be at that point?

So if I've clamped the return and supply lines and I'm still losing pressure, the only possible place to lose pressure would be the injectors correct?

 

Fsm states fuel pressure drop to 21psi after 5 minutes. Do you trust the accuracy of your gage?