car slow to start

[FLBiker]

Hi folks,

We've got a 2009 Corolla, and for the past couple of weeks I feel like it takes an extra second or two to start up.  My wife is due to give birth any day now, so we value reliability right now.  We replaced the battery (we were due anyway) but that doesn't seem to have changed anything.  In reading a bit, it seems like it could be the starter.  Is there something I can do to get a definitive diagnosis?  And is there any way to tell how close it is to giving out completely?

Thanks!

[gt7152b]

First few things I would do: check spark plug gap/condition and possibly replace, clean or replace air filter, replace fuel filter.

It could be the starter but I wouldn't replace it as a preventative measure. I hear you about the baby being almost due but the probability that the starter will give out that very day is pretty slim. Aren't you on good enough terms with any neighbors that you could ask for a ride given that the stars align and you can't start the car? You could also call a taxi.

[HipGnosis]

Sorry, but "slow to start" is to vague for a specific recommendation.

Is the starter/engine turning slow when you engage the starter?
How old is the gas?  Gas goes 'flat' faster than it use to.
Are you current on scheduled maintenance?  I'd specifically look at the spark plugs and plug wires (if your car has them).
If the car has a lot of miles, I might have the injectors cleaned (esp if you usually buy gas from non-name-brand stations).

Congrats on the pending deduction!

[Sid Hoffman]

If the car has a lot of miles, I might have the injectors cleaned (esp if you usually buy gas from non-name-brand stations).

That one is kind of location specific.  If you live somewhere that has ethanol gas, you pretty much don't ever need to worry about dirty fuel injectors.  Ethanol is a crazy strong solvent and I've never heard of anyone getting injector service in the last 15 years since my state switched to ethanol gas.  My current car is 18 years old even and still runs totally normal as far as the fuel system is concerned.  It's got plenty of other issues related to its very advanced age, but fuel isn't one of them.  :)

On that topic though, if the fuel pump is in poor shape, it may take a while to build up enough fuel pressure in the rail to get the car to start properly.  A clogged fuel filter can also inhibit the ability to flow fuel on startup and get the pressure/flow to properly light the engine.  A dirty MAF wire can throw off readings, making the start harder, as can a failing IAT sensor.  If the O2 sensor is caked in gunk then your fuel system may have adjusted the LTFT in the ECU to much leaner than it should be, which can also influence startup.

In other words, it's kind of a big pain to diagnose something like that without much information to go on.

[FLBiker]

Thanks for all of the useful replies!

Re: the neighbors, we've got some that I'd be comfortable asking for a ride, but I'm less comfortable asking them at 3 AM.  Plus, our "favorite" neighbors are away for Spring Break.

Re: slow to start -- I mean that it takes a couple more cranks than usual to turn over.

I believe changed the air filter fairly recently, but I'll take a look at it and the spark plugs.  According to google, the fuel filter on models made after 2002 "don't need to be changed".  Not sure I trust that.  I think we're current on servicing though -- it's my wife's car and she's good about that.

Re: the gas, it isn't old, and we've got 10% ethanol here.

Thanks again!

[Sid Hoffman]

Cleaning the MAF is really easy.  They make MAF cleaner for $5-10 at parts stores.  As long as you buy the right stuff, it's just a matter of taking a few bolts out to get to the MAF, then carefully spraying it with MAF cleaner.  Don't get general throttlebody cleaner; that stuff can leave residue behind that will either ruin or simply throw off the MAF and make the problem way worse or prompt purchase of a new MAF.

It's also entirely possible your speculation is correct and the starter motor itself is having some issues, although generally that kind of part is pass/fail.  As in, they will work totally fine right up until the day they don't work anymore.

You could also try getting an OBD device, such as the OBDLink LX or possibly a generic bluetooth ELM327 device.  I used to have a $15 generic one, although it was a little flaky even when it worked, and quit working after a year of occasional use.  Then if you have an android phone, you can download Torque Pro for $5 and potentially check all the sensors, such as the IAT, ECT, TPS, fuel trim, and so on to help diagnose if the car's engine sensors are delivering good information or not.  The good news here is that generally if a sensor truly is failing, it will usually make the car run badly all the time, not just take a few extra cranks to start.  So it's probably not a sensor.

Although this may not be the answer you want, I would probably just leave it alone and see if the problem gets worse or not.

[HipGnosis]

if the fuel pump is in poor shape, it may take a while to build up enough fuel pressure in the rail to get the car to start properly.  A clogged fuel filter can also inhibit the ability to flow fuel on startup and get the pressure/flow to properly light the engine. 

Fuel injected cars have electric fuel pumps.  Turn the key to 'on'.  Count to 5 to give the pump time to build pressure.  Turn key to 'start'.  If it starts right up, you know it is a fuel pressure issue - probably the pump.

[BlueMR2]

Fuel injected cars have electric fuel pumps.  Turn the key to 'on'.  Count to 5 to give the pump time to build pressure.  Turn key to 'start'.  If it starts right up, you know it is a fuel pressure issue - probably the pump.

I've heard that before, but I don't know which cars it applies to.  Definitely not my Mitsubishi.  Per the diagnostic manual, the fuel pump only runs when it detects the crankshaft rotating.  My Toyotas I've not been able to confirm one way or the other, but the fuel pump is quiet/no apparent operation from simply turning the key to "on".

[PeachFuzzInVA]

I've never seen a Corolla of that generation with a bad fuel pump. Not to say it couldn't happen, but modern fuel pumps pretty much either work or they don't. Also, I'm going to echo the statement that the starter is going to be pass/fail as well. In other words, if it's cranking your starter is fine. I may be asking the obvious here, but is there any corrosion on the battery cables?

[pjm123a]

On one of the automotive forums I hang out on there is a mechanic who describes your condition as "long crank time". A cause of this is a failure in a check valve that gets stuck and allows fuel to seep in while the car is off. This causes a "flooding" condition at the next starting attempt and results in the longer crank time. If you find that the amount of time the car is parked changes the length of the crank time this might be what is happening. In other words if you turn it off and within a few seconds it start it and don't have the long crank time this could mean that there hasn't been enough time to flood things. Also if you let the car sit for a long time and it starts normally then perhaps the extra fuel has evaporated. This mechanic described as part of the diagnosis that the long crank time happened when the car was stopped for an intermediate period of time. No long cranks if it was stopped for a few seconds and no long cranks if it was stopped for a day or so. The long cranks occurred when the car was stopped for a few hours (like if you go into a store to do some shopping then come back to the parking lot). Anyway the component containing this check valve was replaced and the problem was fixed. So if your long crank times are intermittent and variable  this could be the cause.

[guitar_stitch]

Wow...where to start...

Your starter is fine.  As is your battery and likely your cables.

Things to check:

-General Maintenance: When was it last tuned up with plugs, plug wires, filters, etc?  A plugged air filter will cause a whole HOST of problems.
-Fuel pump check valve:  In theory, your pump should retain pressure.  In practice, you could be having a failing check valve.
-Fuel pump getting weak: Your car is not *that* old, but it's not that young either.  If you chronically run the car below 1/4 tank, you could be suffering a failing pump.  You'll need to do a flow test and pressure test to determine that.
-Stuck EGR: You would see a Check Engine Light for this in most cases.  If it's stuck open, your engine will not run well.
-Bad Gas: Using a reputable brand, I hope?

Earlier, I mentioned that your cables are likely fine.  However, there is a chance that there is enough corrosion (resistance!!) in the cables to cause them to drop enough voltage that the ECM is unhappy.  Check the above list first.

There are a few other things you could check (sensors mainly), but start with the basics.