This has been a problem for awhile now. I bought the car from previous owner who can't find out what's wrong. It doesn't happen all the time, just sometimes. Sometimes when it starts, it will start fine and idle great. You can just put it in Drive and drive off. At times, when you try to start it, it will idle first then 5 seconds will slowly bogg the rpm down and shuts off by itself. It can also do this the 2nd time you start it and 3rd time.
Without any other symptoms it is hard to diagnose; could be water in the fuel or a plugged up air filter, that effects idle first, take it out and see if it idles fine, if so get a new one. Take out fuel filter and dump in a glass bowl and analyse for water... get a new one... Is it different when the engine i hot or cold?
If you need further help, I’m available over the phone at https://www.6ya.com/expert/robert_573a00ba7e399076
There is no different whether the engine is hot or cold. Say for example, I can start it up in the morning to go to work and it can happen in the garage. Sometimes it doesn't start, it just randomly happens when it want to.
I've done a full tune on it already. I worked on numerous cars myself, from engine swaps to transmission swap. I'm a Master Mechanic at a Automotive shop and this problem with my Lexus is the first for me. Tried numerous diagnostic tools $10,000+ from Snap-On, Mac, Cornwell and even Matco tools. Just can't pinpoint any type of malfunction.
The full tuneup I've done was replaced the entire fuel pump assembly strainer and all, fuel filter, spark plugs, ignition wires, distributor, even a mass air flow sensor. I know it's not gas for sure.
I even tried using a Snap On Evap Smoke Machine to try to find any vaccum leaks but there is no leak.
Just stump on this one.
Forgot to mentioned, Air filter has been replaced as well. It only does this when you start up the car sometimes. It will never die on you when I'm driving. Only on start up it happens when it wants to.
Use a good diagnostic tool like you mentioned (Or an Android phone with Torque) and look for what the engine sees as coolant temperature, accelerator % etc. and see if the engine sees someting you think is wrong. If the temperature is way to low it is too rich, or too high: too lean. Make sure the coolant and intake sensors are solidly connected. You have taken care of the basics... If nothing else, swap an ecu.
I will see if I can get a replacement ecu this coming week. Thanks for the inputs.
I assume you made sure the ignition keeps on working while dying, i.e. this is really a fuel/control problem. Use a spark tester to see if the ignition keeps on firing.
×
Engine stalls cold or RPM
fluctuates at idle up and down or dies near idle.
This problem is commonly caused by a dirty automatic idle speed control valve and throttle valve but always run a OBD2 fault code as well as the cleaning procedure. Buy a can of throttle valve cleaner (do not use carburetor spray cleaner!) from NAPA or Carquest (made by CRC chemicals) and spray it into the air intake while the engine is running, use up about 1/2 the can, engine will try to stall hold the speed up, shut it down and let it soak for 30 minutes, restart and blow out the remaining fluid, shut it down and disconnect the negative battery cable for 5 Min's to reset the base idle control. If the above cleaning doesn't cure your issues you need to have the computer controlled automatic idle speed control system diagnosed and repaired by a dealer or electronic engine control repair shop.
316 views
Usually answered in minutes!
×