I have a 2003 RAV4, Drives ok, but engine dies if stopped with AC running or in drive. One day Check engine light came on vehicle would not start. replace both gas pumps. Once the car is moving it is ok,, but once stopped then problem develops. Cna be intermittent some times. What do you think is the problem??

SOURCE: 2003 RAV4 Engine Replaced, Electrical Issues

first it is plausible that it could be a ecm problem however if it were replacing the engine was a waste of money and the problem never got solved, and i highly doubt it's a ecm problem to begin with. with the ecm it does learn as you are driving but the only way it does that is by checking the sensors and compenstating the performance from the results. if you were leaking fluid and it was red it was from your transmission or your transaxle if it's 4 wheel drive. If your yellow light comes on most people assume that it has something to do with the computer, but often times that in newer vehicles they don't always have seperate gauges for the oil,electrical,etc. and if you have a low level in fluids it will cause the check engine light to come on. I have over 25 years of experience in engine building i have replaced alot of engines in different vehicles over the years and i have yet to install one in a RAV4, however basic engine principles still apply. all engines run the same and transmissions are the same. the trick is to use common sense and take your time in diagnosing problems. Now you stated you felt a loss of power brfore you had to tow it. I'm going to ask you a few basic questions and I would like you to reply back with the answers. this will help me pinpoint the problem instead of guessing like most under qualified mechanics that just want your money

SOURCE: fuel system

Check the fuel system, chenge fuel filter. clean the fuel tank.

SOURCE: 2002 sequioa sudden stall

Often when the battery is disconnected or replaced the computer will lose it's learned idle settings. You could try letting the engine idle in park until the engine temperature comes up to normal and leave it like that for a few minutes, then put the Air con on and let it idle again for a few minutes, then switch the air con off and put it into drive. If it does not stall, let it idle in drive for 2 minutes or so, and then do the same with the Air con on. This should relearn the base idle settings and stop it from stalling on you. Before you carry out this procedure you should make sure that when you replaced the battery you didn't remove any other plugs or knocked anything that may be causing the fault. If you try this procedure and it still stall when you select drive, you will need to get a Mechanic to check the vehicle over.

Hope this helps,
Mark.

SOURCE: '98 Toyota 4Runner Won't Idle -Intermittent Problem

Hi, I had the same problem. Nothing showed up on the "machine" but the Toyota mechanic replaced the idle control valve. It was pricey but it fixed it.

SOURCE: engine light is on ,code P0171, hesitates when start driving

Hi. These are symptoms that represents poor fuel distribution. i recommend changing both the filter and fuel pump in this case. I would also inspect the entire injection system for fouled wiring or damaged housing(injector housings).

IF the spark plugs haven't been inspected or changed in 9 months, i would pull them for a visual inspection as well. replace the wires and plugs if they are not in a proper condition.

Last, i would add a fuel system cleaner to scrub the fuel lines and rid the system of any carbon deposits that may be present in the intake manifold.

Check the Intake manifold gaskets for damage.