Not the IACV?? What is it then? Tips Please!

[sepulchral]

My 2001 4-cyl auto solara has

1) a low idle in Drive/Reverse... when i shift to N or P the idle goes up to 1k.

2) at idle and while driving anywhere in partial throttle the car sort of hesitates (sometimes multiple times), almost like a momentarily loss of ignition/power/seems to do it more when the car is warmed up or hot.. it doesnt throw any more codes.. It almost feels like the car is bucking or something.

3) at WOT (wide open throttle) the car does not hesitate at all, and goes.


For the last 2 weeks i've been throwing P0505 code, yesterday i changed my complete TB with a newer clean, working IACV, TPS, etc.. the car still hesitates!

Anyone? How can i tell if its engine or transmsision related? It happens at idle as well remember. What could this be and not throw codes?

[Simpler=Better]

How clean is your EGR? How old is your fuel filter? Are you using fresh NGK platinums?
I recently had a similar issue that has been resolved by cleaning the TB, EGR, IAC; and changing the fuel filter and plugs.

[sepulchral]

Originally Posted by Simpler=Better

How clean is your EGR? How old is your fuel filter? Are you using fresh NGK platinums?
I recently had a similar issue that has been resolved by cleaning the TB, EGR, IAC; and changing the fuel filter and plugs.

What did you do to clean your egr?

[frenum49]

Also check that there is NO GAS in the vacuum line going to the fuel pressure reg on the cars fuel rail. Looks like a small UFO shaped diaphragm. Unplug the vacuum line going to the top of it. If it is wet with gas, replace it.

[sepulchral]

Good news, the car threw two codes...

P0300 and P0304


Is it coils or wires? Plugs looked fine

[Mike Gerber]

P0300 is a random misfire. P0304 is a misfire in cylinder number 4. No guarantee without running the coil diagnostics, but my guess would be plug wires since you are getting a missfire on cylinder number 4. If you want to check the coils you can go over to the Camry forum over at AutomotiveForums.com and download the generation 4 Camry factory service manual. The manuals are stickied there at the top of the forum and are available for free downloading. The manual will have the test for the coils. If the plug wires are original and there are a lot of miles of the car (your original post doesn't say), you might just want to repalce those as routine maintainance and see how the car runs. I would not buy a cheap set of wires. They usually only last about 1 year in my experience.

Mike