- This topic has 4 replies, 3 voices, and was last updated 7 years, 8 months ago by
.
-
Topic
-
I have a 2000 Toyota Sienna with 137k miles that had a strange episode of misfires yesterday.
I drove it about 45 minutes on the highway, parked it for an hour while wife and I went for a walk at the park but upon returning, the van ran very rough when I started it. When I tried to drive, it was bucking and I couldn’t go more than 5 mph then the MIL was flashing.
After limping back to my parking spot, I stopped the engine. Checked the hood area, then restarted it. Then it ran perfectly but still a solid MIL.
I drive home the 45 minutes, then scanned for codes- P0300 (random misfire), P0301,P0303, P0305 (cyl 1, 3, 5 misfire, all on bank 1), P0172 (system too rich), P1130, P1150 (bank 1,2 A.F sensor 1).
The next morning, I started the engine a few times, graphing the A/F sensor voltages and saw no issues. While doing this the MIL engine light cleared itself and since then hasn’t come back on.
How do I troubleshoot this now if it’s running perfectly? The spark plugs are due to be changed at over 100k miles but could all 3 plugs misfire and then just recover? All on 1 bank only?
I will change the spark plugs only because they are past due, but I don’t have any confidence it will solve what caused this issue. Any thoughts?
Thanks,
-
Replies
-
There are several causes to engine misfire.
Poor Fuel Delivery
Bad Spark Plug(s)
Bad Spark Plug Wires
Weak Fuel Injector
Leaking Fuel Injector
Vacuum Leak
Flash Over or Carbon Tracking
No Voltage at the Coil
These are usually a cause to continuous misfiring.In your case being that it occurred only once (so far and hopefully)
You might be looking at some type of vapor lock in the fuel system that cleared itself.
Bottom line is unless the issue is repeatable and sustainable at which point it could be diagnosed.
Chances are that you will be hard pressed to isolate the problem.Low battery voltage/low voltage to the ecu…. Check for a clean and tight battery connection and do a load test on the battery… Check voltage to battery while running with all accessories on..
Karl
Thanks for the suggestions. When I get home from work I will load test the battery as well as measuring it’s running voltage. It’s not a new battery > 5 years.
Ok, the battery measured borderline “weak” on my Harbor Freight load tester but the real issue I saw is that, while running and headlight and blower motor on full speed, there is only 13V on the battery terminals.
Then I moved the negative DMM lead over to the frame of the alternator and then I got over 14V. To double check, I measured about 1.1V between the negative battery post and the frame of the alternator.
So this weekend I plan to chase my ground connections around the engine bay and clean them up- everything looks corroded in there due to no splash guard under the engine bay to protect from salt spray in the winter.
Thanks for the spot on tips.
- You must be logged in to reply to this topic.