2000 Camry Misfiring - Toyota Nation Forum : Toyota Car and Truck Forums

A-Rob · 11-23-2009, 06:44 PM

I've got a 2000 Camry 4cyl with 165K miles. It just started misfiring, but only while in gear. If it's in neutral it runs perfect but under load it misses all the way to 3500 RPM and smooths out. The plugs are all good and the plug wires are new. Any ideas?

hill8570 · 11-23-2009, 08:33 PM

I assume the CEL / MIL light is on? What codes are you getting?

***fenixus*** · 11-23-2009, 08:45 PM

what spark plugs and wires are you using? have you replaced the fuel filter ? might be something about it or dirty fuel injectors maybe. any codes might point you closer to the right direction.

A-Rob · 11-24-2009, 11:40 PM

The CEL is on but I don't have a code reader and there's no way to get it to town right now without towing it. I'll change the fuel filter tomorrow and at least try to eliminate that as the problem.

***fenixus*** · 11-24-2009, 11:47 PM

you can try borrowing one of autozone's code readers, meaning pay for it and ask if you can bring it back later for a full refund.
they do code reading for free if you can bring car to them.

good luck!

A-Rob · 11-25-2009, 10:27 AM

Fixed it! Turns out the plugs were bad, even though they didn't look fouled or eroded. Here's my theory: the valve cover gasket is leaking, and I'm betting that the plug well seals are leaking also. There is a recessed area on the plugs by the tip and somehow oil is getting up there and screwing up the plugs. $50 worth of NGK plugs later and the thing runs like new. I'll change the gasket and seals next week and hopefully I won't have to change plugs for a while.

***fenixus*** · 11-25-2009, 10:34 AM

good job! glad you've got it sorted out

depending on mileage, you can finish the tune up (wires and fuel filter) or have fun with it already

A-Rob · 12-04-2009, 07:24 PM

Well, the problem is back - sort of. It started missing at low RPM's and idle, while in gear. I replaced the valve cover gasket, plug tube seals, and the PCV valve then cleaned the plugs but nothing has changed. It shouldn't be the coil packs because it was fine for a few days, and I checked the resistance of the plug wires and they are all good. It isn't throwing CEL codes this time, either and as soon as the car starts moving it stops and runs fine.

carsrus · 12-04-2009, 07:36 PM

Hmm it sounds like possibly a weird vacuum leak. So it runs bad when you drive, but good in park?

Passibly a vacuum line is split and "opens up" when the engine flexes in gear a bit. Once the load if off the engine the line comes back together.

Does it run better once it gets all warmed up?

***fenixus*** · 12-04-2009, 07:50 PM

might be also something clogging IAC valve. it can screw up idling badly - that is if drives good, just idles poorly.

cleaning the TB (and IAC hole) might help.

How to: Cleaning Throttle Body -4 Cylinder Engines- With Pictures

A-Rob · 12-04-2009, 08:09 PM

The IAC makes sense. I've cleaned it before, but there was oil in the manifold when I pulled the PCV valve this week and maybe it is fouled up prematurely because of that. I'll clean all of that tomorrow and maybe that will do the trick.

***fenixus*** · 12-04-2009, 08:42 PM

yeah, if you had trouble with it before then it might be acting up again.

I had to clean TB twice to do it right (had trouble with uneven and low idling revs).

spray like half of TB cleaner can into TB while using toothbrush to brush all the oil sediment off the butterfly valve (both sides - lock the throttle wheel with screwdriver to get access), wipe excess with paper towels. then spray a lot down into IAC hole and brush it again with toothbrush until black dirt disappears. it should help if this is the root cause.

good luck! and post back if that doesn't help, you may have other trouble too.

A-Rob · 12-05-2009, 12:13 PM

OK, I cleaned the TB and IAC valve and now the car idles at the correct RPM (I forgot to mention that it seemed a few hundred RPM high earlier) but now it will occasionally dip below 1000 RPM and it seems like it wants to stall out for a second. This is driving me crazy.

***fenixus*** · 12-05-2009, 12:17 PM

good, this one checked. my '00 i4 idles when cold ~ 1,100 than drops to about 900 rpm (Park) and sits at ~700rpm at idle on Drive.
now check vacuum hoses for leaks/cracks as mentioned above, you might still have another problem. have you replaced recently the fuel filter and air filter ? any CELs by any chance ?

A-Rob · 12-05-2009, 12:53 PM

Quote:

Originally Posted by fenixus

good, this one checked. my '00 i4 idles when cold ~ 1,100 than drops to about 900 rpm (Park) and sits at ~700rpm at idle on Drive.
now check vacuum hoses for leaks/cracks as mentioned above, you might still have another problem. have you replaced recently the fuel filter and air filter ? any CELs by any chance ?

The CEL only came out while I was connecting and disconnecting the IAC connector while cleaning it, no codes prior to that and it was probably because it stalled out a couple of time. The air filter is good, and I'm going out now to change the fuel filter. That is a pain, but at least it will remove another possibility.