2002 Toyota Sienna V6
Hey guys.
I worked on my girlfriend's mom's 02 Sienna today, she was telling me about how it wouldn't start.
I bought over my jump starter because it sounded like the battery just needed a jump. This wasn't the case. The battery didn't have a problem cranking the engine, it was the motor itself that didn't want to stay running. I turned the key and I felt a few cylinders fire immediately like normal, but after half a second of cranking, it stopped and went back to relying on the starter, and then fired a few more times, and went back to the starter.
I let it sit a few minutes and tried starting it with my foot at about 5 percent throttle, it started right up and continued to run. I took my foot off very gradually and it smoothly shut down. As it shut down, all of the lights went dimmer than they usually are. I know that they should because voltage is around 14 when its running and 12 or 13 when its not. I could tell it wanted to stay running.
It has 140k on it and the alternator was still factory so I replaced that, it improved a little. I didn't have to give it as much gas to keep it running. I took my foot off the gas and it still smoothly shut down.
The next thing that I suspect is the battery. She has had the van for 4 years now and the battery has never been replaced, so it makes sense. I am going to have it tested before I ask her to buy a new battery just to be sure that it's the battery. I would continue throwing parts at it but it's not my money and I don't want to make myself look bad.
My question is, is this most likely the problem, or could it be something else? The check engine light was on a while ago, but it was for a fuel cap issue. I don't think that would cause the engine to not be able to stay running.
It's possible that it's the battery.
You can test it a few different ways.
My Impreza has a central coil pack that is easy to unplug, so;
I unplug the coil pack
Hook up my volt meter to the battery, position the screen so that i can see it in the car
Crank for a few seconds
Generally, if it stays above 9-10V while being cranked, it's in good shape.
You can also pull the fuse for the fuel pump or injectors, any of them will prevent it from starting.
Any time i work on an electrical issue, I clean every ground i can find, as well as the contacts on the battery. Pretty simple, unbolt the ground and sand all of the contact surfaces, bolt it back together. If you want to go the extra mile, you can coat the ground with dielectric grease AFTER it is assembled. You want to get as little as possible on the contact surfaces.
When I run into a problem like this I suspect 2 things off the bat;
- mass airflow sensor
- idle air control valve
The battery is not the problem. Like you said, it's cranking the car strong enough to halfass start it and keeps cranking as it's faltering.
The idle air control valve, on the other hand, is what lets air into the engine when it's idling and the throttle plate is closed. There may be no coincidence that it idles when you just barely crack the throttle. If this IAC valve becomes clogged with shit it obv won't idle. Or if it just fails shut. Remove it, check and clean it.
The MAF doesn't make as much sense.. but I've seen this exact issue with dirty or dead ones. Pull that MAF, inspect the element, and clean it with MAF approved cleaner spray.
There's ways to electrically check both, but the MAF involves a scantool, so that's tough. Do both of these things and report back.
[img]http://ww2.justanswer.com/uploads/ebrock63/2010-06-21_165140_2010-06-21_104901.png[/img]
[QUOTE=clutch2;46722733]When I run into a problem like this I suspect 2 things off the bat;
- mass airflow sensor
- idle air control valve
The battery is not the problem. Like you said, it's cranking the car strong enough to halfass start it and keeps cranking as it's faltering.
The idle air control valve, on the other hand, is what lets air into the engine when it's idling and the throttle plate is closed. There may be no coincidence that it idles when you just barely crack the throttle. If this IAC valve becomes clogged with shit it obv won't idle. Or if it just fails shut. Remove it, check and clean it.
The MAF doesn't make as much sense.. but I've seen this exact issue with dirty or dead ones. Pull that MAF, inspect the element, and clean it with MAF approved cleaner spray.
There's ways to electrically check both, but the MAF involves a scantool, so that's tough. Do both of these things and report back.
[img]http://ww2.justanswer.com/uploads/ebrock63/2010-06-21_165140_2010-06-21_104901.png[/img][/QUOTE]
You can check the MAF by unplugging it and starting the car.
The ECU has a bit of a default setting to run without the MAF sensor.
If it runs better without the MAF plugged in, it's pretty easy to say that it's dirty or toast.
A scan tool is not needed to check a MAF, they can be tested with a multimeter. As for how? I have never had to go that far, it was usually pretty clear that it was toast and did not require further testing.
IACV is another possibility, though that is very low miles for IACV issues. The ones I have dealt with were at 200k+ miles and clogged with oil from the PCV/head/crankcase vent system.
It's fairly simple to clean, just have to be sure you order a gasket for it. Some vehicles have engine coolent run through it, and the gasket keeps the coolant from being sucked into the intake.
Good point with disconnecting the MAF.
I'm most used to dealing with Ford MAF issue at the old shop, since they sucked, lol. On those it output a signal in Hz, which is impossible to read without a scantool IMO. A bad one will still output, but it won't read enough. For example a good MAF, when snapping the throttle, will jump to around 1000grams/s intake. A bad MAF, when snapping the throttle, will only read 500grams/s. It'd be tough to diagnose in that scenario using a meter.
[QUOTE=clutch2;46728481]Good point with disconnecting the MAF.
I'm most used to dealing with Ford MAF issue at the old shop, since they sucked, lol. On those it output a signal in Hz, which is impossible to read without a scantool IMO. A bad one will still output, but it won't read enough. For example a good MAF, when snapping the throttle, will jump to around 1000grams/s intake. A bad MAF, when snapping the throttle, will only read 500grams/s. It'd be tough to diagnose in that scenario using a meter.[/QUOTE]
Like i said, ive been pretty lucky with MAF sensors and havent had to test one beyond unplugging it.
With Subaru's, i do know that you can test the MAF sensor with a multimeter.
I believe quite a few of the 90's/early 00's import MAF sensors can be multimeter tested, but i wouldn't be surprised if it is common for domestics to use the Hz setup.
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