Hard starting with warm engine

Thanks I learn something everyday from all you great folks here , no wonder Costco gas lanes long . @Herniator

 

Yea sometimes temp sensors can make them flood when hot..

 

If temp sensor shorts out it can make the fuel system think it's neg 40 degrees out. It will go full rich and flood the engine. The next time it happens get someone to crank it while you stand near the tailpipe and watch the exhaust when it finally starts. If you see a cloud of black smoke its getting flooded..

Try cleaning the maf..

Ask the dealer if there is any software updates available that address hard hot restart s..

 

Yeah, could be. I have to think the techs were looking at those things, but who knows? When I talked to the service writer, I mentioned the possibility of a bad sensor, and they did replace the CPS. The dealership has been in contact with the Tech Line looking for a solution. It doesn't seem like it should be this difficult...but what do I know, I'm not the expert.

 

The fuel pump was not replaced, they decided to test the pump under several conditions instead. The pump tested ok. The next step is to replace a possible bad number 6 injector. They ordered an injector, will be bringing it back to them next week. Frustrating...

 

I'm not sold on the fancy gas idea. I used to think gas made a difference, but after seeing my friend's 4Runner go 450k miles, with a majority of that being from the cheapest ghetto no-name gas station, I lost that thought. Was further supported after seeing the shit fuel overseas that people would use and their vehicles are still running fine. I've always heard about top tier fuels, yet everytime I've seen someone recommend it, it never helps the problem.

Maybe, there might be a long term benefit, but I'm skeptical whether it really matters.


OP, my guess was fuel pump, but sounds like that is out. Following to hear the culprit.

 

Checking the list of Top Tier "fancy" gas, I've used nothing but that in the truck, either 89 or 87 octane. It appears I'm the only one here with this persistent problem; it's like I won the lottery...

 

I'm late to the party and it's a shot in the dark, but I had the same problem with mine right from the start - I eventually figured out it was me not the truck. I was used to my previous truck that electronically controlled the starter run time which the Tacoma doesn't do, so I was "bumping" the starter thinking it would run on its own to start. Once I learned to go back to old school run the starter until it fires I haven't had the problem.

-BC

Edit: In addition the action of "bumping" the starter several times actually made the problem worse until the starter had to be run extra long to fire the engine.

 

Yea forget about gas.. buy a cheap code puller that will show some data and watch the rpm pid.. If the crank sensor is faulty you will not see the crank signal show up for the first few seconds and then it will show up all of a sudden and the engine will start. If you have a crank signal or RPM signal same thing it will show from the very first second you start cranking

 

Crank signal /RPM signal (same thing)

 

Short of taking it to the dealer or a repair shop and letting them diagnose it buying your own little code reader would be the smartest thing to do in my opinion. Leave it plugged in to the truck every time you start the truck watch the data and look for the missing ingredient when the problem happens. Crank signal ,mass air flow signal ,Etc

And by crank signal I mean RPM or engine speed signal.

 

Previous car which was direct injected, long cranks were an early sign of the high pressure fuel pump going out. Different animal but was/is a fairly common failure on a BMW n54 engine.

Also, any one know if the 3.5 uses port or direct injection on start up?

 

It's definitely the truck, not me. I haven't done anything different than before the problem surfaced with nearly 12,000 miles on the truck. Also, a Toyota tech and service writer duplicated the problem. It's just not supposed to turn over for many seconds without firing, something is wrong. And, it never does it on cold starts.

 

No worries... like I said a long shot but I thought I'd throw it out there!

-BC

 

Thanks, appreciate the input.

 

I believe the 3.5 is direct injected. Hi pressure fuel delivery could be an issue..

 

OP could try adding some propane or starting fluid when long crank is happening and see if it responds/fires off when alternative fuel is added.

It would require a helper at every hot re-start tho..

 

Thanks, but I want Toyota to do their job, not me. Besides, the hard starts are unpredictable and it usually will fire on the second attempt. But it has taken as many as four attempts.

 

I hear ya..

The 4 attempt scenario is a good opportunity to add some fuel yourself and see what happens. The next time it no-starts 1 time, stop trying to start it, have a helper squirt some starting fluid in the air filter housing just as you start cranking it for the second time. If it fires off it is likely a fuel issue. You could even record some video and show it to the service writer or the tech

Respectfully, this is something to try If You get tired of waiting for the dealer and you want some answers for yourself..

 

Dealer replaced #6 fuel injector today. After several warm starts the problem seems to be gone. One of the starts was after a 2.5 hour shut down which has been the most problem prone time frame. The invoice has the description "poor starting hot soak". That was the first time they used that description. Hopefully this issue is now history, we'll see. I am thinking of adding fuel injector cleaner to my gas.