Misfires/stalls, I've Hit The Wall.

[rxstarscream]

Hey, new to the forum. Posting this in a couple other places as well, I'm absolutely stuck. Car in question is a 2003 Toyota Rav4 2WD, around 150,000 miles.

The problem I'm having is random accelerator hesitation, engine misfires and stalls. Sometimes it idles rough, sometimes it doesn't. When it does idle rough it will die periodically. The stalls, misfires and fail to accelerate typically happen from a dead stop to anywhere under 40mph, but it has happened once while I was on the freeway at around 60mph. The acceleration issue is intermittent, you'll be accelerating and it will just drop off, like you're not even pressing the pedal. There are no codes being thrown reliably, if at all, post the oxygen sensor. I've even gone as far as to unplug sensors during operation (MAF and CPS) and received nothing.

These are issues that have already been addressed:

4/13 ECM - The common transmission/ECM issue with the Rav4, not shifting properly or shifting at the wrong RPM's. Pulled the ECM and sent it to Circuit Board Medics in April of last year, it was outside the window for Toyota to do a warranty repair. They had it back within a week, installed it and the car was returned to service. Everything was functioning correctly.

6/13 Water Pump - Noticed a bad shaking sound coming from the engine, upon investigation the pully for the water pump was wobbling. Replaced the water pump the car was returned to service. Everything was functioning correctly.

9/13 Battery - The car died one day while driving, pulled the seats out and accessed the fuel pump to make sure that is was turning on. Nothing. After a little more investigation we noticed the car wouldn't turn over. Replaced the Battery, car began functioning correctly. Returned to service.

***At this point I began to encounter the issue and pursued in the best way I knew how***

4/14 Upstream Sensor Bank 1 - Car was idling rough and threw a code, replaced a sesnor and returned to service.

4/14 Fuel Pump - Later on in the same month the car was hesitating and sputtering, removed the fuel pump to look inside the tank and at the filter. Appeared to be pretty dirty, replaced the filter and pump at the same time to avoid future maintenance. Returned to service, everything was functioning correctly.

5/14 Spark Plugs -
Car began sputtering/misfiring and would die moments after being turned on. Pulled the plugs, one had a cracked tip, they were all covered heavily with deposits. Replaced the plugs, returned to service. Everything was functioning correctly.

***At this point the problem resurfaced and has persisted to this day***

5/14 Cleaned MAF - Car showed current symptoms, removed the MAF and saw it had carbon buildup, cleaned/dried and reinstalled, returned to service. No change.

6/14 Valve Cover Gasket - Noticed some slight oil leakage around the cover, removed the cover and found cracks in the gasket around where it was leaking. Removed and replaced.

6/14 Replaced MAF - Continued current symptoms, replaced the MAF. No change.

6/14 Injectors - Inspected the injectors to ensure they were functioning correctly, each one was delivering fuel. Replaced o rings during this process. Problem persisted.

***At this point I took the car to a shop just down the road due to lack of progress***

6/14 Replaced Ignition Coil Cylinder 1 - Mechanic showed me the coil pack for cylinder 1 had a slight crack from the boot up, spark was escaping. Visually confirmed. Replaced the coil pack, problem persisted.

6/14 Crank Position Sensor - Our OBD readers were not showing any codes, SnapOn was at their shop and used one of their readers. Diagnosis was a bad CPS, sensor was replaced. This was thought to have fixed the issue.

Mechanic claimed that the car was running okay, let it idle for 15 to 20 minutes. Walked to the shop, checked it out, paid and left. About 15 minutes later after I got some gas I was accelerating from the light and it started again. Shortly thereafter it died while I was going 20mph. Pulled over, started the car and pulled out and drove down the street. Idled rough and had the same acceleration issues until I got it home.

I'm at a loss, any help would be greatly appreciated.

[Uncle Bob]

Sounds like you have covered most items, not sure what I can add....although just a though ,check all the earthing points, ones to the ECU, engine block, chassis, sometimes faults can be as basic as that.

Also, of all the jobs you have done, have you ever checked the compression of the pistons ? Maybe if your problems is not electrical, you could have a sticky engine valve or lifter ?

[buklau111]

You say you only changed one ignition coil, maybe try changing all of them. I don't know how many cylinders a RAV is.

[rxstarscream]

Sounds like you have covered most items, not sure what I can add....although just a though ,check all the earthing points, ones to the ECU, engine block, chassis, sometimes faults can be as basic as that.

Also, of all the jobs you have done, have you ever checked the compression of the pistons ? Maybe if your problems is not electrical, you could have a sticky engine valve or lifter ?

All of the ground points are clean and secure. Have not checked the compression, it never occurred to me as the engine is fairly clean internally. Judging from everything I've seen so far, oil changes were the extent of the previous owners maintenance.

You say you only changed one ignition coil, maybe try changing all of them. I don't know how many cylinders a RAV is.

It's a 4 cylinder. I wish I could... but without knowing that the coil packs are the issue I can't justify it. We're talking about 400.00-450.00 for 4 coil packs.

[rxstarscream]

You say you only changed one ignition coil, maybe try changing all of them. I don't know how many cylinders a RAV is.

Guess what? Took it to the dealership for a diagnostic... Ignition coil 4. Replaced the coil and it runs better than it has since she purchased it. Moral of the story, if your car has a mystery problem like this take it in for a dealership diagnostic.

[Uncle Bob]

You say you only changed one ignition coil, maybe try changing all of them. I don't know how many cylinders a RAV is.

Guess what? Took it to the dealership for a diagnostic... Ignition coil 4. Replaced the coil and it runs better than it has since she purchased it. Moral of the story, if your car has a mystery problem like this take it in for a dealership diagnostic.

So maybe it could have been cheaper in the long run, and a faster diagnosis, to have used the dealership in the first place.....hey we all live and learn :)

[buklau111]

Hahahaha I did mension ignition coils xD

[Red Yaris 54]

Sometimes you just have to "hit the wall" before you see sense and take it for professional help! :)

Pleased you have it sorted out