Question about 1999 Toyota Sienna
Replaced the spark plugs, the wires and the coil pak
If cylinder compression is too low, the car may not even start because of it. Have a shop do a compression test or a leak-down test to check the internal health of your engine. A good engine should have pressures of 150-200 psi in all cylinders and be close to each other. A worn or high mileage engine may have pressure as low as, say 125 psi, but if still balanced (close readings), would still run decent. Compression below that, especially below 100 psi, is serious trouble. ignition spark refuses to ignite the air/fuel mixture and you get a misfire-a non-working cylinder. Low compression can be caused by worn piiston rings or poor valve sealing. Low compression in 1 or 2 cylinders can be a valve problem, burned valves or valves not seating properly.
A leak-down test will check each cylinder and if there is a problem, the test will find the cause of the problem.
Posted on Dec 11, 2012
Testimonial: "thank you for answering, when we ran the compression test it read 70psi so the mechanic advised me to get a new engine. what do you think?"
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Posted on Jan 02, 2017
Your plugwire cabling is too 'NEAT'
Make SURE that cables don't run parallel and DO cross over one another as running parallel induces HV pulses in the adjacent cable resulting in misfire.
Get under the hood and mess them up a bit ;-)
JUST the NEAT wiring, not the firing order!
Posted on Mar 26, 2009
light flashes when comp. picks up a skip pull code and it will be po300 random miss p0301 p0302 p0303 p0304 all are for that # cyl that has the miss best bet change wires and plugs check for oil on wire to plug end in spark plug hole leaking valve cover gasket or spark plug tubes...
Posted on Dec 31, 2008
Hey Dan, It cannot hurt to change the Plugs and wires. Make sure and Check all the Fuses and Relays also. Sometimes the Realays can blow or just get old and send a Code also.
Posted on Jan 23, 2009
I respectfully disagree.
A P-0300 will NOT be set in a Corolla by a dirty fuel filter.
Replacing the fuel filter could be a very costly operation, as I have observed that the fuel line threads that connect to the fuel filter easuily get damaged when removing the fuel filter.
In short, don't replace the filter until you are SURE that it is the culpit.
In this case, the fuel filter is NOT the culprit..
Save your money; and your time.
Additionally, premium fuel does not clean fuel injectors. That expense would be a waste of money. The engine will actually run WORSE on premium fuel; the engine is NOT designed to run on premium. 87 or 89 (better choice/89) is the grade to use.
If you really want to track down the P-0300 code, which is a multiple/random cylinder misfire, I would look at the quality of the fuel in the car; ie water in the gas. Second, I would remove the plugs and examine them closely. A worn center electrode will also set the P-0300 code, as will bad/weak plug wires (over 5 years old).
Please feel free to contact me back if you need further assistance. Thanks for choosing FixYa for assistance.
Posted on Mar 05, 2009
SOURCE: spark plugs replecement
I replaced my spark plugs just recently on our V-6, hope you have long thin hands. The plugs & coils on the front half are under the decorative cover. Remove with an allen wrench. Take off the coil & disconnect the wire connections (Note: these coils are fro the front and rear plugs, that way you do not have rear coils to remove, thank god). Pull out the plug wire cap, use the cap not the wire, its easy on the front.....the back half gets fun. Use an extension on your plug removal socket and take out he plug. Replace the plug and put it all back, repoeat for the front three. The back three are located behind the intake manifold, gonna have to do a lot of feeling and reaching around the intake. Again remember pull on the cap not the wire, if you pull the wire out.........gonna have to get new ones. The left most rear plug was the hardest for me to reach lots of stuff in the way, A few choie words and some beer and after a while I got it. Have fun every thing went well after I got it out.
Posted on Mar 24, 2009
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