Toyota Nation Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
We bought my son a 2000 Avalon XLS as his first car. At first everything ran fine. However, we soon started to have problems with the car not starting so I replaced the battery. However the problem persisted, and we picked up a new problem: they car wouldn't stay running. Assuming its a charging use, I replaced the alternator. Still random starting problems, but then we picked up a new problem: I could get it to start but it would sputter and die immediately. I read that a completely dead battery can reset the computer and that a clogged intake can be exasperated. So I took apart the intake and cleaned it. Seemed better for a bit, but soon resumed.

Eventually, I got the car to start and stay running long enough to take it for a spin. After about 30 minutes the idle problem was gone and the car drives normally. Occasionally we still have random idling problems. Last week he drive to school, it idled down in the parking lot, then wouldn't even turn over. I had to jump him to get him home.

Fast forward to today. Son goes to start car, and it won't stay running. Sputters and dies. Then won't turn over. I jump it, get it running, floor it, and the rpms are bouncing up and down, and eventually no matter how much gas I give it, it idles down below 500 and dies. Multiple attempts I finally get it started and in gear and drive it for 20 minutes wherein appears to act fine.

Any ideas what is going on?
 

·
Registered
2000 Avalon
Joined
·
94 Posts
You might want to check them again, as there may be a new one now that this has started. My Avalon has the light on too. It is a bad heater circuit on the bank one A/F sensor. I pull the codes every now and then to see if anything else has shown up. It sounds like you have a fuel problem. I would check the MAF sensor readings first.
 

·
Registered
2000 Avalon
Joined
·
94 Posts
Follow up: checked my Avalon and MAF readings (engine hot at idle) are between 3.75 and 4.75 g/s. Under hard acceleration, 3800 RPM, MAF was 88 g/s. If MAF doesn't go up with RPM, clean it. If that doesn't work, replace it. A friend of mine has a Corolla that would stall out at idle and a new MAF fixed it.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #6
My son installed an aftermarket air intake and modified it (ie cut a hole) to fit the MAF in. Could it be that because its not sealed tightly this could be an issue, or does it just need to get flow through the tube to measure?
 

·
Registered
2000 Avalon
Joined
·
94 Posts
Yes. You shouldn't cut a hole to put a MAF sensor in. They are specific to the car. Whoever makes them, you never have to cut a hole. Ever.
 

·
Registered
2000 Toyota Avalon XLS
Joined
·
37 Posts
My son installed an aftermarket air intake and modified it (ie cut a hole) to fit the MAF in. Could it be that because its not sealed tightly this could be an issue, or does it just need to get flow through the tube to measure?
Hey mat can you take a picture of this modded air intake? I'd love to see what this looks like!
 

·
Registered
2000 Avalon
Joined
·
94 Posts
Hey mat can you take a picture of this modded air intake? I'd love to see what this looks like!
A picture is a good idea. Live stream data from the MAF, ECT, IACV and IAT sensor, RPM and fuel trims. Start the car, record data at idle, 1,500 RPM and 2500 RPM. start with a cold engine. Test until it fully heats up. Download the data. MAF should roughly increase with RPM if the other sensors are working. Any kind of air leak past the MAF will screw up the car's engine.
 
1 - 9 of 9 Posts
Top