Intermittent Long Cranking

Hi everyone,
I just picked up a 09 Tacoma with the 2.7L in it 3 days ago and it seems to now have a problem where if I try to re-start the engine after a couple of hours of it being off, it takes 2 or 3 tries for the engine to not immediately die after starting. However, it starts just fine on a cold start. I was doing some research and I think its the fuel pressure regulator but I'm new to Tacomas so I don't know for sure. Is there a way for me to test the regulator?
Thank You!

 

Pop the number 4 coil out and if the tip is oily you need a valve cover and spark plug tube gaskets. Good luck!

 

Pull the vacuum line off the regulator and see if it's wet with fuel, if it is then the regulator is leaking. If it's not then it's probably not the regulator.

It could be an injector leaking or the fuel pressure bleeding off but you would need a fuel pressure gauge to see if fuel pressure is holding with the engine off.

That might would cause a misfire, it would affect starting a warm engine.

 

The regulator regulate the pressure. It does NOT maintain pressure.
The pressure check valve is in the pump/tank.

1. Measure the fuel pressure while the engine idles.
   
   
   
   Standard:
   281 to 287 kPa (2.87 to 2.93 kgf/cm2, 40.8 to 41.7 psi)
   
   
   
   

1. Stop the engine.
   

1. Check that the fuel pressure does not change for 5 minutes.
   
   
   
   Standard:
   147 kPa (1.5 kgf/cm2, 21 psi)
   
   

 

Fuel pressure problems are likely to be far more pervasive than this. I would start with cleaning the throttle body, given that this happens somewhere between hot starts and cold starts.

 

Thank you guys. I will test the fuel pressure and clean the throttle body soon. I suspect it’s a fuel issue because when the problem happens it almost seems like the fuel system needs to be primed like I just opened and drained the system.

 

If it was a problem like you describe, it would get progressively worse, the longer it sits. You said the problem is there after 2 hours of sitting, but is fine when fully cold. There is a check ball in the fuel pump that keeps the fuel from draining back into the tank. When this starts to fail, the symptoms go from none at a few minutes to bad at some time, usually hours or days. The interval from good to bad is variable by problem, based upon the leakage rate.

Your reported symptoms sound more like the computer not adjusting the Throttle plate appropriately for the conditions (temp based). When it is kind of warm, the ECU uses only a moderately open throttle, but when cold it goes much further open. Computer learns this position and remembers it. Fill the blade up with carbon and the throttle doesn't pass as much air and therefore struggles to catch after starting, but runs fine once it does.

 

Thank you I will try to clean the throttle body tonight.

 

I just cleaned the throttle body and waited about an hour and a half and it’s the exact same still. I forgot to add that once I do get it started and instantly shut it back off and start it again it starts normally so I don’t think it has to do with the temp of the motor. I will get a fuel pressure tester and check that next.

 

that is a bit different than the first post. So, if it has sat for any meaningful amount of time it struggles, but if started immediately after shut down, it struggles? That is symptomatic of the check ball problem in the FP I and others mentioned. Your original post said it started fine when cold, which implies sitting for a while.

If fine after 1 min and problematic at 1-2 hours, but fine after a full day, then I am struggling to see this as a check ball issue. You should determine all the variables involved, as it could be sensor related.