Hesitation while starting:

[DRC]

Greetings all,
It’s been a while since I posted anything, life and kids will do that to ya! Anyway the other day when I went to start my 4runner after work it cranked for about 4 seconds before the engine fired up. Which was very odd as it never did this before. I thought bad gas as it was just filled up so I ran the tank empty over the week and filled up with gas from a different gas station. Today it did it again. When I started it up after work it cranked for about 4 seconds almost sound like it was about to stall and then fired up. I almost wanted to pump the gas pedal. It has never hesitated when I first start it in the morning after sitting all night. Only when I start it up after work.

I am reasonable confident that the battery and starter are fine as it cranks strong. No clicking or anything from the starter. It just hesitates to fire up. Like it’s not getting any gas or ignition. The plugs only have about 10k miles on them and the wires look good, etc. The closes post I could find to a similar issue was talking about cleaning the MAS. But there seemed to be some debate if this is at play during starting. The battery is original so its 7 years old, but its cranking strong so I don’t see that being the problem but I may replace just because its old. My understanding is the fuel filter and pump are in the gas tank so they are virtually un-serviceable. And I have never received any error codes or anything so I am at a loss.

Does anyone know if this is a known / common issue? Any suggestions how to trouble shoot / fix?
08 4runner, V6, 10k on iridium NGK plugs, 86k miles

 

[Rancid13]

If I had to guess I'd say battery for sure. May not be dead but on its way out. That plus cold weather recently could've done it in. 7 years is a long battery life

 

[beliy25]

its the battery,give it another 2 3 cold night and you wont be able to even turn on the ignition.happend to me a month ago.exactly the same symptoms and 2 days later,dead battery.

 

[DRC]

I found out a while back if the battery is low not dead but it still cranks the engine,the Toyota's computer is not seeing enough battery power to turn on the fuel pump and start the engine. It's a Toyota software item.

Sounds odd but it would not surprise me at all. Our Sienna would forget how to idle if the battery was disconnect for too long. Go figure.

I think I am in agreement with everyone that the likely issue is the battery. I went ahead and replaced it today with a Duracell from Sam's Club. For the money, 94.95 plus tax, this seems like a heck of a battery:

BCI Group Size:27
CA at 32 degrees F:1010
CCA at 0 degrees F:840
Reserve Capacity:140
3 year replacement warranty

I'll report back after a few days...

 

[JDH]

4runner hesitate on starting

Hi, I'm having a very similar issue right now also. I don't really suspect the battery at this time but am interested in your findings, how did you make out?

 

[gm350reratliff]

I also think my OEM battery on my 4th gen is going dead. It doesn't really crank any longer but I can tell it is slower. I might put my volt meter on it today and verify. Almost 7 years to production date and 129k. Not to bad for an OEM battery IMHO.

 

[YotaDriver]

A dead giveaway that your battery is going bad in a 4Runner is when your rear wiper starts making a single sweep of the window upon start-up, even though it's in the "off" position.

 

[DRC]

Well it looks like replacing the battery worked in my case. Since replacing the battery I have not had any issues starting. I am in Chicago and we have had some really cold weather the past few weeks, down to 7 degrees, and I have not had one issue starting.

As it turned out the battery from Sam’s Club did not fit. The terminals are reversed so positive was where the negative hook up is. I did not realize this until I went to install it. I stood there for about 5 minutes looking at it as if somehow it would magically fix it self. I do this a lot as I get older…LOL. Anyway, I returned that battery and picked up an Interstate MTP-24F for $98.00 plus tax. It’s slightly shorter than the original but fits just fine and has a CCA of 800.

Thanks for the help all!

 

[DRC]

A dead giveaway that your battery is going bad in a 4Runner is when your rear wiper starts making a single sweep of the window upon start-up, even though it's in the "off" position.

Very interesting, I recall on at least one occasion this indeed happened. At the time I just thought it was odd. One of those what the heck things but did not put anymore thought into it.

 

[molliebrowne]

I want to revive this thread bc I am having the exact same problem with my 09 sport. I have new plugs, cleaned MAS, new PCV valve, cleaned throttle body air intake valve (i dont know if thats the official name), new air filter, new battery and still the problem with the start. Like it wants to stall. Upon starting, there is a more noticeable fuel smell outside the car and im now getting much lower gas mileage (I have had several tanks of gas since noticing this, thinking it could have been bad gas). Im at a loss of what to try next. Maybe O2 sensors? Anyone have any ideas of next steps?

 

[waypoint]

I want to revive this thread bc I am having the exact same problem with my 09 sport. I have new plugs, cleaned MAS, new PCV valve, cleaned throttle body air intake valve (i dont know if thats the official name), new air filter, new battery and still the problem with the start. Like it wants to stall. Upon starting, there is a more noticeable fuel smell outside the car and im now getting much lower gas mileage (I have had several tanks of gas since noticing this, thinking it could have been bad gas). Im at a loss of what to try next. Maybe O2 sensors? Anyone have any ideas of next steps?

That sounds like leaking fuel injector(s) dumping raw gas into one or more cylinders after shutdown. When it starts up, is there a puff of black smoke out the tailpipe?

Diagnosis is fairly simple fuel pressure test, taking readings both during idle (~41 psi and stable) and after shutdown (should hold 21 psi for 5 minutes). I suspect you'll find good reading at idle, but rapid loss of pressure after shutdown. In this case it's likely time for new injectors (use only Toyota injectors from a reputable dealer, not aftermarket or rebuilt junk).

I've used this kit on mine: Amazon.com: BETOOLL Fuel Pressure Test Kit 0-100PSI with 9.49,7.89,6.30 Fuel Line Fittings: Automotive

From the manual:
h) Measure the fuel pressure at idle. Fuel pressure: 281 - 287 kPa (2.87 - 2.93 kgf/cm 2, 40.8 - 41.7 psi)

(i) Stop the engine.

(j) Check that the fuel pressure remains as specified for 5 minutes after the engine has stopped. Fuel pressure: 147 kPa (1.5 kgf/cm 2, 21 psi) or more
​

To isolate the faulty injector(s), crank the engine but shut off before it starts. Then pull spark plugs and inspect for gasoline wetness.

edit: also, pull the oil dipstick and take a whiff. Smell like gasoline?

 

[Drcoffee]

Old thread, but I would look to the fuel pump. A weak pump will be slow to fire up even tho the engine is cranking over.

If the battery is known good but the engine seems to spin slowly while cranking, then check out the black negative battery cable. Battery acid will leach under the plastic cable sheath and prevent a good ground connection. Google “replacing big 3”. I have had to rebuild the ground wire on my 99 4runner before. Its a fun project.