[Monico]

Gentlemen,

Please help me with this problem.

Car: 2002 Toyota RAV4 "L"

Major Fixes: ECU-resolder ; Fuel Pump Replacement; Fuel Injector Replacement

Minor Fixes: Idle Air Control Valve Cleaning w/ new gasket; MAF Sensor Cleaning

Most Recent Fix:Recently replaced old IAC gasket (which was ripped) with new gasket.


Symptom: Idle at cold start is around 1000 RPM. Idle once warm is around 0-200 rpm, does not stall.

Tried to take out fuses so on and so forth. Nothing yet.

Other issue: After an oil change w/ seafoam approx. 6 months ago my timing chain tensioner seems to have given way, now has rattle sound from chain hitting valve cover I think?

Do you think it's the timing chain tensioner giving me the bad idle? Please Help.

Thanks.

Jesse

 

[Blogson]

If the camshaft chain tensioner is not keeping the chain properly tensioned it could be possible that some slack is taking place with the chain which is resulting in engine valve operation being somewhat out of synch with the crankshaft, which could cause idle and other problems. Conceivably this could take place even though cam chain tensioners are situated on the part of the chain's operation which takes place after the chain has turned the camshaft. In any event if the cam chain is the cam chain is contacting covers obviously eventually the cover and possibly the chain will be ruined and need to be replaced.

 

[Monico]

Any other opinions gentlemen? Not ready to pull the trigger on all those parts just yet

 

[Saturday Morning]

200 RPM? I didn't know that was even possible... or that 200 RPM would even register on the tach...Does it have good spark and fuel at all cyl?

 

[Monico]

I can say that fuel is not an issue, I will pull the spark plugs tomorrow (expecting to see white due to lack of fuel in the past).

 

[Saturday Morning]

Before you remove the spark plugs pull the plug wires one by one with the engine running and watch for a notable change in engine RPM (or engine stalling) If the engine bogs down (or stalls) it means that cylinder is getting fuel and spark. Replace the plug wire, (restart the engine if necessary) and move on to the next cylinder. When you get to the cylinder where you pull the spark plug wire and there is no change in engine RPM that indicates a dead cylinder. It may be not getting fuel, or spark.. or have a physical problem creating a lack of compression.

 

[Saturday Morning]

To check spark, shut off the engine and remove the spark plug from the head. Reconnect it to the spark plug wire. Ground the spark plug against the metal engine or chassis and crank engine while looking for spark. If there is good spark, check fuel and compression. If no spark is visible, swap out the plug for a new one and try again. If spark is visible it was a bad spark plug. If still no spark then that indicates a bad coil or spark plug wire.

 

[Monico]

I appreciate the quick replies, I'm not sure how to pull the spark while I've got the airfilter/maf in the way. Do I remove that, take out the spark plug, reassemble then turn on ? O_O

 

[Saturday Morning]

The general idea is to individually deaden each cylinder (one by one) while observing the engine for notable a change in idle speed. The simplest way to do this is by removing the spark. Give me a sec to look up that engine... 2.0L 4-cyl right?

 

[Saturday Morning]

Well bummer. I found these via Google Image search:
http://www.moibbk.com/images/toyota-rav4-engine-1.jpg
http://images.gtcarlot.com/pictures/66458111.jpg

Looks to be a coil on plug design and all of it is buried under that massive air cleaner asy. I think I can just make out one coil in the first photo peaking out from underneath the air box. Is it possible to loosen up the air box enough to access the electrical wires to each coil pack? Maybe you can un-clip the primary leads since there are no plug wires to pull?

 

[Monico]

Upon further contemplation on this problem: The RAV4 does not experience any problems with power while in motion. Wouldn't spark plugs affect misfiring/ overall driving experience?

Please Advise.

 

[Saturday Morning]

Yes it should and in theory a misfire should also cause the CEL to come on and it to store a code. Is it possible to loosen up or remove the airbox and start the engine?

 

[Monico]

It can be done, just the issue is the MAF may get a false reading, what do you have in mind?

 

[Saturday Morning]

My thinking was fairly linear. If is idling steady at 200 RPM without surging it could be a dead cylinder. If it's surging I would tend to think throttle body. ...

 

[Monico]

It seems as if the idling has improved.... perhaps the ECU needed time to readjust after fixing the gasket leak by the IAC.


If it's a dead cylinder wouldn't it trip the ECU?

Thanks for all your responses Saturday.

 

[earthrealm]

Strange problem,
didnt know a car wud still be running, and not stall at 200rpm

 

[JustinC25]

May be a dumb question, but have you cleaned the Throttle
Body ?

Sent from my SM-N910V using Tapatalk

 

[Monico]

Thanks for the reply Justin,

I cleaned off the throttle body extensively. It seems when it's warmed up the idle like to be either 700 rpm down to 200 rpm.

I have to replace the timing chain tensioner and I will check the timing and so forth. I hope that fixes my issues.