Cold Starting Issue

2011 V6 Double Cab w/ ~120k miles. I’ve been having some trouble with cold starts lately. Have to turn the key to the run position for a couple seconds then start in order to get it to fire up and even then it may take several attempts. I took it into a shop several months ago for a general inspection prior to a long road trip and they said my alternator was “overcharging” my battery and the battery was getting pretty old but it was still good. I figured the voltage regulator on the alternator was going bad, hence the “overcharging” so I replaced the alternator and battery as a precaution before winter. Still having the starting issue and it’s getting worse.

I have tried cleaning my mass air sensor and replaced my sparkplugs in 2018. Is my fuel pump going out? What about the fuel resistor next to the battery or the fuel filter? Starter? As I said it’s only got 120,000 but it’s had lots of starts doing survey work for owls last year. I didn’t know about cooling off the pump with gas, I usually just fill it when it’s empty.

Any solid advice before I spend more $$ on troubleshooting this would be great!

 

When the key is turned to "on" it runs the fuel pump and then will shut the fuel pump off if the engine isn't started within a few seconds. By turning the key on and waiting a few seconds prior to starting the engine it's priming the fuel lines and such. My guess is fuel is draining back into the fuel tank instead of staying still in the fuel line like it's supposed to when the engine is off.

As far as which specific part in a Tacoma that controls fuel flow like a check valve does I do not know.

 

You’re going to have to be a bit more specific. When you say won’t start, you mean it cranks fine but won’t start? Doesn’t want to crank? Cranks slowly?

If you’ve recently done the urd fuel pump/filter upgrade, some people were having issues with a hose clamp cutting the hose causing the fuel pressure to bleed off. Also certain pumps would bleed pressure off by themselves. There was a recent long thread on this subject, improving the urd fuel pump filter install, or some like that.

I’ve read in other posts that the Tacoma’s don’t turn the pump on when you switch the key to the on position, it only turns on when you start cranking. I find this odd because every other fi system I’ve fiddled with turns the pump on with key on.

Once you provide further details, I’m sure you’ll find the help needed.

 

It cranks fine and quickly, and there’s no clicking noise like I would expect from a faulty starter. After 2-3 seconds of the key being in the start position the truck sputters and runs very rough. Once I back it off to “on” it dies immediately. On the second try it usually starts, recently I’ve had to try 3 times. Once it’s warmed up the issue goes away.

 

Sounds like my 2011. Cold mornings engine on a slight incline it seems to be fuel starved. Good thread and look forward to the response.

 

probably a leaky check valve down in the tank for the fuel pump. Try turning the key to on, let it sit for 5 secs, turn all the way back off, turn on again, sit for 5 secs, then try to start.

 

Sounds like injectors

 

It could possibly be a bad ignition switch. I've seen the same symptoms and it ended up being high resistance in the key switch in the on position, on other things. I don't know it the Tacoma's ignition switches fail like that.

Oh, warmed up problem goes away, probably not the ignition switch then.