Hey there,
I’ve got a 1999 Toyota Camry with a V6 and 106,000 miles on it. I was traveling between Boston and Philadelphia yesterday, and somewhere about right in the middle, I started to notice a problem with my car.
I was in cruise going about 70 up a hill when the car started to stumble a bit. As time went on, it became more difficult to get up any hills without my speed dropping down to about 35. On the downside of a hill, I could pick back up to about 65, but the next hill I would stumble again (not in cruise anymore) and limp my way up to the top of the hill with my flashers on.
I’d noticed the car was stumbling a teensie bit prior to this trip, but only at very low speeds.
The car has a new fuel filter (which I’m now told might have been a life-time fuel filter to begin with) which I installed a month or so ago.
I also installed some new spark plugs recently. The car drove over 300 miles with those new spark plugs without any more stumbling than I’d had before.
I picked up a fuel pressure test kit from AutoZone last week to try to diagnose the small stumble (before the gigantic stumbling started) and found that it couldn’t be used on my car (the V6 Camry) because the car has a quick-connect fitting to the fuel filter instead of a banjo fitting.
Is this a fuel pressure regulator problem, perhaps? A fuel pump problem? An injector problem? Fuel rail problem? Any ideas on how to diagnose without a fuel pressure gauge?
Thanks for your help.
The car has a new fuel filter (which I’m now told might have been a life-time fuel filter to begin with) which I installed a month or so ago.
There’s no such thing as a lifetime fuel filter. There are longer life filters…but they need to be changed…Some are in the gas-tank which make it very difficult to change…If you can change it then it should be done regularly. I changed the filter on my 98 Pathfinder once a year and every time it was FILTHY…
I also installed some new spark plugs recently. The car drove over 300 miles with those new spark plugs without any more stumbling than I’d had before.
What kind of plugs??? Some cheaper plugs may run fine for a while…but even after a few hundred miles they are junk. Stick with NGK or Denso plugs. Those are the plugs designed for your vehicle.
As to what is causing the problem…There could be several different things that could cause it…Fuel flow…Dirty injectors…Bad ignition component (i.e plugs)…If a timing chain the chain could have jumped a tooth.
Like MikeInNH I wouldn’t assume all is well with ignition system, including the “new” plugs. There is also basic testing of your coils (this is coil on plug, yes?) that can be done if you have a multimeter. Autozone’s online repair manuals may have info for that.
Checking the fuel pressure is also the right thing to do. You should be able to find an adapter fitting for your car if the gauge you bought doesn’t fit it.
Is the check engine light on?
Thanks for responding.
MikeinNH: I’ve heard that these long-life fuel filters don’t last forever, so I changed mine anyway. It couldn’t hurt, right? But a filthy fuel filter is a good sign your filter is actually doing it’s job, right?
Concerning dirty injectors: I did run some fuel injector cleaner through a while back, but without any discernible difference. Maybe the stuff you can buy at a auto parts store or a gas station isn’t really worth much.
The plugs I put in are Autolite Double Platinum plugs. When I took those out, the plugs that were in there were also Autolite plugs.
Cigroller: The check engine light came on about 100 miles after I first started noticing the bad stumbling.
“The check engine light came on about 100 miles after I first started noticing the bad stumbling”
Well, lets put an end to blind guessing then. Go to a large chain auto parts store (e.g. Advance/Autozone). Have them read your error codes - they do it free. Write down the exact codes (format: P1234) and post them here. This won’t tell you exactly what is wrong or identify bad parts, but it give a starting point for diagnosis.
Would have saved us some time if you told us up front that the check-engine light came on.
Before you do anything else get the codes read…That will help eliminate any guessing on our part.
Yes a dirty filter does mean it’s doing it’s job…the problem is…a filter can get TOO dirty and start restricting flow…or even worse bypass the filtering altogether and send dirty fuel to the injectors.
As for injector cleaner…what did you use…some are better then others…and sometimes you need more then just ONE application. Gumout is almost worthless…Try Seafoam or Chevron.
The only time I’ve ever had any good luck with Autolite plugs was on my lawnmower…I’m NOT impressed with their plugs…You’ll be much happier with NGK plugs…And don’t buy the platinum if you can…NOT needed. Platinum does NOT give you better performance…Just longer life.
Since the last thing that was worked on was the spark plugs, start there.
Pull all the ignition coil sticks off the cylinders, and check the spark plugs, and see if there’s damage to any of the spark plugs, or if one or more are wet with either fuel or oil.
Reinstall the spark plugs if they all check out okay, or replace them all with trusty NGK plugs instead. (why people use autolite/champion brand plugs, I’ll never know. I don’t even trust them in my lawnmower.)
When you reinstall the coil sticks, feel for the click, to ensure they are properly snapped onto the plugs. This is a step a lot of people miss with coil sticks. From Toyota’s to Porsche’s, this is the most common thing missed by DIYers.
Let us know how that goes.
BC.
Thanks for the responses.
I’m back from AutoZone, and I got the trouble codes for the car.
They read as follows: P0301, Cylinder 1 Misfire detected
Probable causes:
Weak or missing spark
Plugged fuel injector
Engine Mechanical Fault
Large Vacuum leak specific to cylinder
And a second trouble code, P0300, Random cylinder misfire condition
Probable cause:
Lead Air/Fuel ratio/ fuel pump
Fautly MAF/ VAF sensor
Large Vacuum Leak
Ignition system fault
So, I don’t know if you’ve ever tried to put the plugs in one of these Camrys with the V6, but it is a huge pain for three of them. It looks like the ones that are the most trouble (as in access is not very good) are the plugs on cylinders 1-3. Cylinders 4-6 are a cinch.
I had trouble with all three of these. It was tough getting them torqued down, could that be my problem then? (Besides the aforementioned issues with Autolite plugs).
I had trouble with all three of these. It was tough getting them torqued down, could that be my problem then?
Most definitely…My wife has a 08 Lexus 350…and I know how hard those back plugs can be…I have to almost lay across the engine to get to them…I can’t see them…it’s all feel.
First thing I’d do is replace the plugs…Go to a reputable autoparts store and buy some NGK or Denso plugs…
I’ve heard Tom & Ray refer to TCS: Toyota Camry Syndrome. I think it’s when carbon builds up on the valves and they don’t close all the way. I think the symptoms are similar to these: losing power especially up big hills.
Does anybody know what year Camrys are affected by TCS or which engines?
The only 6cyl I’ve had to do was a minivan and I got the rear three plugs from underneath and behind - crawling up underneath the car on jackstands. There’s a good change you wouldn’t have room since the Camry is much smaller but it may be worth a look.
On this engine the plugs MUST be removed from the top.
Yes, I actually have removed the spark plugs from a Camry V-6.
And yes, it is a pain, and takes a long time.
The repair manual I picked up said that the best way to do it is to disconnect the intake manifold plenum, and I believe that would be the best way to do it.
Chances are, the spark plugs are fine, and you just need to press the coil sticks onto the spark plugs until they click properly.
Since the code says cylinder one, start with that one, and see if that solves the issue.
BC.