'08 Highlander - Hard Starting

[megahurtsss]

This past 2 weeks my 08 highlander sport (V6) has been taking a while to start cold. It will just crank for a good 5-6 seconds and nothing. I will try again and it will crank for another 5-6 seconds and finally start.

I was suspecting a fuel filter, but have not been able to find any information. Maybe no fuel filter??

Anyone experience this?? I added some injector cleaner hoping it will make a difference.

[deadrx7conv]

What injector cleaner? Many do nothing. Hopefully you picked something from one of the major brand names.

Fuel filter is a sock on the fuel pump. Unless you got a seriously bad tank of gas, you probably won't have to worry about it for 200k. Use a different fuel station and make sure its on the toptier list.

Since mileage is unknown, I would also change/check the air filter, the sparkplugs, and clean the corrosion off all the battery/alternator power/grounds....

[sweeneyp]

Ive never have this happen to my highlander, but my 94 jeep grand cherokee had this problem. New sparkplugs/wires fixed that. I can't imagine wires/plugs going bad this early on an 08... How many miles do you have on yours?
As for fuel injector cleaners, I've used seafoam in all of my vehicles and I love it. I put 1/2 the can in the vacuum line and the other half in the gas tank. Good at removing junk and preventing it too. I tried a lot of other "cleaners" before I finally settled on seafoam and found most of it to be just about worthless (not just in my highlander, but in other vehicles that really need it, i.e. a 250k mile 13 year old LX470... seafoam REALLY helped that car)

EDIT: ignore the ridiculously horrible seafoam rant. Apparently I can't make sense when I'm tired haha. Look down 2 posts for what I meant to say

[AVConsult]

A little bleary eyed or needing a composition course? Is Seafoam "worthless" or the best stuff you've ever used?

[sweeneyp]

Originally Posted by AVConsult

A little bleary eyed or needing a composition course? Is Seafoam "worthless" or the best stuff you've ever used?

haha oops . I wrote that at like 1:20am so I was a little brain dead at that time. I just read my post and realized I wrote gibberish, haha my bad.
I meant to say that it was the best stuff I've ever used, and all the other cleaners were worthless/no noticeable results. And that was tested in all my vehicles ranging from my highlander to old jeeps/lexus's.

[megahurtsss]

mileage is 53,000. How is the spark plug change on an 08 highlander. Does this involve taking apart the whole engine, or are they easy to get to?

[sweeneyp]

Originally Posted by megahurtsss

mileage is 53,000. How is the spark plug change on an 08 highlander. Does this involve taking apart the whole engine, or are they easy to get to?

Well changing the plugs is a bit of a nightmare. BUT, according to the manual, they are suppost to last 120k miles (though my dealership told me between 75k-90k miles), so they definitely shouldn't be going bad at 53,000. The front of the engine faces the passenger side wheel, so when you pop off the engine cover the front facing bank plugs are staring you in the face. But the back bank faces the firewall and you have to disassemble the air intake/manifold to get to them so definitely not an easy task. Only reasoned I said plugs was that you might have had a lot of miles on your highlander (my jeep had about 80k on the plugs I replaced and those plugs weren't meant to last that long...). What I mean is that I knew mine were bad and it fixed the problem, yours shouldn't be bad.

Is the starter making weird noises (besides taking a long time to turn over)? like the starter motor is straining more than normal, or just sounds different?

And once the engine is running does it idle roughly (erratically or at unusual rpm), misfire, semi stall on acceleration, sound different, or down on power?

[AVConsult]

Leave the plugs alone until 120k+. They're iridium. My '02 HL iridium looked new at 140k when I finally got around to changing them.

Your problem is more likely fuel related, since the HL uses plug on coil and the likelihood of 6 simultaneously goobered plugs or coils is very small.. Low pump pressure, *maybe*. Or, simple as defective fuel pump relay that developed high resistance in contacts. Or, defective block temp sensor, or stuck IAC motor. You need a diag computer attached and catch it in the act.

Can you hear the fuel pump running when cranking during it's acting up--someone may have to stand by the tank to hear it.

[megahurtsss]

Thanks for info guys! Your right about the plugs, I doubt they need to be changed. the car runs perfect, just the initial cold startup in the morning. Maybe I picked up some bad gasoline.

[JMSinMD]

Have your battery tested, most last 3-4 years before needing to be replaced.

[dixon422]

Our '08 (67k miles) has been doing this now for the past couple of weeks. I suspect a fuel issue as well. I had this problem on a Jeep Grand Cherokee a few years ago. I had to have the key on for 3-5 seconds before trying to start it so that the fuel pressure would have time to build up. There was a check valve somewhere in the line that was stuck partially open and would allow the fuel to recede back into the tank and drop pressure to the rail. If the Jeep was only shut off for a few minutes, it would fire right up, but overnight and after parking at work, the pressure had time to drop off and would require the "priming" time.

I suspect a similar issue with the Highlander, especially when I've heard the fuel pump running while it's been parked in the garage for a few hours...I'm guessing a response due to a loss of pressure in the system.

If I figure it out, I'll follow up here.

[nov0798]

Dixon
Thats pump you hear running a few hours after is not fuel pressure. Its some type of vapor recovery something or other.

I recently replaced my plugs, what a friggen nightmare. Basically you can get to the rear ones, but you have to do the following.
Remove the windshield wipers
Remove the black fascia piece over them
Remove the wiper motor
Remove the black tray type thing from the vehicle between the struts
Remove the angled bracket that goes over the front coil (cmon Toyota really?)
Remove the nut that holds the wiring harness to the valve cover (again really?)
Then you can get to the plugs.
You basically need to work blind and by feel, but its doable.

Really need a topside creeper to make the job easier.

Took me 1.5 hours total, what a mess!

[TrailDust]

Originally Posted by dixon422

I suspect a similar issue with the Highlander, especially when I've heard the fuel pump running while it's been parked in the garage for a few hours...

Originally Posted by nov0798

Dixon
Thats pump you hear running a few hours after is not fuel pressure. Its some type of vapor recovery something or other.

Correct, it's the vapor recovery system. See the Common Problems & Solutions sticky thread for a relevant link.