engine problems (not running smothly) at low rpm

[nz-dude]

hi guys,

I've just been traveling with my camry 2000km on a road trip and besides the death of my suspension nothings has been happening. No overheating, nothing ... back to town driving I've recently noticed that while waiting at traffic lights the rpm change a very little bit ... so far nothing to worry ... then today I had some 2h of bad stop and go traffic which made idle and low rpm engine problem more present.

between 700 and 2000rpm the engine feels like it would run without one or two cylinders .... so in den evening i was doing a few kilometers on the highway, all good on high rpms, full power is available ... if I slow down to 1800rpm and try to accelerate, then it feels like the engine is getting too much of fuel .... back on normal roads, it stays for a short time normal but then turns into the initial symptoms of pretty bad engine running.

On my Volkswagen this is usually a dirty throttle valve, which is oily ...

Not sure what the issue is with my 2.5l V6 camry .... I check the air filter, looks pretty clean, I couldn't check the spark plugs since I didn't have the right tools handy to remove the engine cover .... any other suggestions, what the cause of my problem might be?

All liquids are fine, had recently a cam belt/water pump and oil service ...

thanks for your help!

[Mike Gerber]

Try cleaning the throttle body paying particular attention to spraying the cleaner liberally down in to the square or diamond shaped port in the base of the throttle body. That port leads to the idle air control valve where your problem may exist. After spraying the cleaner in to that port, clean out the rest of the throttle body while the cleaner soaks in to the idle air control valve. Here's a link to the procedure on another Toyota V6 engine:

http://www.4x4wire.com/toyota/mainte...throttle_body/

Mike

[Mister_Perkins]

Sounds like your timing may be off. If your timings off a tooth, it will be sluggish at lower rpms and seem fine at higher rpm

[2win2rbo]

You may have a look at your vacuum lines. You may have a vacuum leak. Look for vacuum lines particularly close to the firewall.

[Mister_Perkins]

an easy way to check for a vacuum leak is to get starting fluid and spray it around the intake manifold and vacuum lines. If the idle changes, you have a vacuum leak

[nz-dude]

cheers guys.

I have had some major development yesterday ... so basically I had to move all my stuff to a new place and since my camry was working i decided to use it and towed a trailer full of furniture and stuff half the day. All good, still bad idling but i had to move ... then I dropped a friend and had another 90min of stop and go traffic ... close to home, power was almost gone, couldn't rev engine anymore, made it to a parking place and the engine died ... I tried to restart it, worked a couple of times, but it never went higher then 500rmp ... called roadside assistance, they came and checked some stuff ... in the meantime, I'ven't been able to start the engine ... not even with giving throttle while starting ....

besides the obvious stuff they sprayed starting fluid into the air intake, didn't change much.

they then checked one spark plug and couldn't get any spark ... then checked whether the spark distributor is powered -- it was ...

anyway, it was poring cats and dogs ... couldn't get much help from this stage on ... had to leave my car and finish the other things ... I'll pick up the car soon and probably bring it to a garage.

The roadside dude asked what the status of my cam belt is, well .. has been done recently I answered ... but when Mister_Perkins said that the timing/cam belt might be off ... this could actually still be the case ... so I'm just wondering if in case the cam belt is broken or far off ... whether I wouldn't get a spark?

Might be a spark plug or spark distributor problem and the cam belt as well???

thanks for your help so far??

Any other suggestion what I can do before towing the car to a garage on tue? I do have some basic tools, a multimeter etc ....

In other words I should be able to change the spark distributor ... but if it is timing belt related, then I'll just bring the car to the garage where the timing belt job was done ... Cheers!

[Mister_Perkins]

Hmm .. well, runs on coil packs so the first thing I would do is pull your front 3 coil packs off and inspect them. Also bring along a Spark plug Socket and remove the spark plugs and inspect them.

When they sprayed starting fluid in the car you said it started but stalled.

Theres so many things that could be wrong with the car as far as it starting and staying running.

things off the top of my head to check would be

1.) Fuel - make sure your getting good fuel pressure
2.) Spark - you've already done this and you are getting power to the coil packs
2a.) spark plugs - make sure spark plugs have proper gap
3.) Compression - make sure you have good compression
4.) Emissions system - Make sure your IACV, EGR, etc.. are not clogged this can cause a no-start condition
5.) Mass Air Flow Sensor - Get some electric safe spray and try to clean it off, spraying the electrical board inside to remove dust.. etc.. This would cause a start / stall condition / lack of power
5a.) If no MAF, may be a faulty MAP sensor
6.) Crankshaft sensor - No start scenario
7.) Throttle Position Sensor
8.) ECM - Computer could be faulting out.. You would more than likely see a check engine light.

[Mike Gerber]

Does this 2.5 liter engine use a distributor? If so, I would suspect your problem is a cracked coil inside the distributor. They can crack and short themselves to ground on any metal inside the distributor. This can produce a weak or no spark condition. This condition is usually worse in wet/damp weather and you did say it was raining cats and dogs. I would isnpect the coil inside the distributor and replace it if you find cracks in the plastic.

Mike