Not starting well

Hi all,

My 4Runner is slow to start, sometimes. Doesn’t seem like it’s the battery (it’s a red top less than 2 yrs old), I don’t know if it’s the alternator. Could it be a fuel pump? It feels like it’s not getting enough gas to start. This problem only happens 60% of the time when starting now. But it’s getting worse. Any ideas?

 

Does it seem to lag when starting or does the motor spin pretty fast? If it's spinning over like normal and not firing, you have another ussue.

 

Optima red top?

 

I'd start with a fresh tank of 93 octane fuel and a can of Seafoam

 

Yes

 

It definitely lags when I try to start it.

 

That’s a great idea. Seafoam is added to the oil? What about adding something to my fuel?

 

You can go to Autozone or O'Reilly and they can test it for free. If you trust your dealer you can have it tested there, my daughter's battery died in her Rav4, the dealer in Murray Kentucky installed a 7 year Toyota battery for $193 out the door.

 

Great idea. I actually bought it at OReillys.

 

Add it to your gas tank when you fill up with fresh 93 octane

 

My experience with the optima batteries, their warranty is better than the battery. Easy to have it tested at a box store.

 

Your runner is several years old and the wiring is several years old. I had a red battery cable to starter motor corrode inside the red insulation.
It passed voltage fot testing but not the current/amps needed to start. If you decide to replace parts I suggest least expensive first.
Any chance you got some bad fuel?

 

Did you get it figured out @donnermel?
I am having a similar issue w/ my 4th gen. It will lag on start sometimes. The alternator was on its way out, so I replaced that but now it will still lag sometimes on startup. Going to put in a bottle of Techron and fill it up w/ fresh gas today and see how that goes.
The battery tested good at Autozone. Runs like a top after it starts up so leads me to believe it may be the starter or a weak battery (even though it tested good). Just curious to see what your fix was.

 

Optima is trash these days, plus the standard electrical system can’t charge an AGM battery correctly.

 

This ^^^
AGM batteries require electrical adjustments to charge them correctly.

 

I haven’t figured it out totally. But I’ve been filling it up with 91 at Chevron the last few times and it’s starting slow a lot less now. I have no idea if I got bad gas or need a new alternator. But for now- I’m just crossing my fingers!

 

Before you had said it was “lagging”. What does that mean?

Is the starter motor cranking very slow? If it is, then it’s your battery, or corrosion on wires, or something electrical along those lines.

But if the starter motor cranks strong, but the engine itself doesn’t catch, start, and stay running smoothly…then it might be an issue with a dirty throttle body, dirty mass air flow sensor, dirty air filter with mice in, or possibly fueling issues.

 

Does anyone actually load test their batteries? Just because it’s 2 years old doesn’t mean it hasn’t gone bad. A slow crank would point to the battery. Check connections and load test the battery.

Seafoam doesn’t do jack sheet on a vehicle you drive and maintain properly.

 

^This is the answer OP

 

Need to dig out the OG load tester from my toolbox that wrecked batteries, and glowed red during use.

 

I’ve tested my battery, it’s fine. I’ve changed my air filter, I’m only running 89 or 91 fuel for the moment. I’m not sure how to check the mass air flow sensor or the throttle body but those are great ideas. When I said it lags at starting sometimes- like it’s making the starter sound but not catching. It doesn’t do it all the time either. The cold starts in the morning are normally fine too. But after I’ve been driving it. Let it sit for 1/2 hr, then start it again is where I have problems. It always eventually starts, but I really feel like it’s not going to one of these times.

 

Can you take some video of it doing this and post it? I feel like it would help us, help you.

Also Optima used to be cool like 20 years ago, they've been trash for some time. Thats why people keep circling back around to it. But lets not focus on that until we get some video.

 

Take it to a dedicated car electrical place and have them check the battery. I was having weak starts and Autozone checked and said the battery was fine. I kept having problems and went to a car electrical place and they checked the battery and said it was bad. Put in a new battery and have no more problems.

 

A simple DIY is to monitor the battery’s terminal voltage while cranking. If you measure below 10 volts your battery is suspect…either needs a proper charge or replacement.

edit: the rest of my post vaporized so I’m adding it back here…

The 10 volt margin is for a typical Lead Acid…for AGM, which should be at least 12.6v prior to starting should not fall below 12V under load.

 

Do you have a check engine light after it starts up. Have you checked for codes?

 

Well on my 4th gen that was having a similar issue. We just put a new battery on it. It tested good at Autozone but a couple of weeks of this mess and took it to Oreilly and they said it has a bad cell. Took it to Walmart and they said the same thing and we bought a new battery from them. Installed and starts perfectly again. Just letting you know what resolved our issue. Could be worth load testing it if you have not yet.

 

So the Optima battery is not to blame. Could be a degraded fuel pump. Was the fuel level low in the tank when you had the starting problems?

 

I agree. Check the fuel pump or the fuel pump module making sure its getting the proper signal from the ECU to turn on correctly every time you go to start the 4R. Just my 2 cents.