timoc42

hey guys,

recently, i have this really weird problem with my car.

when i start up the car, the tach usually goes to about 1000 RPM right ?

well, sometimes, the tach goes to like low RPMs like 200 rpm (between the first and second line)
The engine just like shudders and it stays there.
The engine does not die.
When I rev the engine up to like 1000 to 2000 rpm or more to try bring up
the RPM, it just drops down again to low 200 rpm.

However, if I switch off the car, and restart it, nothing happens. Everything is back to normal.
This does not happen everyday or all the time, but it happens like once every 3-4 days.

Any ideas?

Tim

flipside909

Erratic/rough idle. When was the last time you had your timing checked?

timoc42

timing checked ?

you mean timing belt change ? or what ?
I dont understand you.

amf1932

I think he meant the ignition timing, not the timing belt, but I don't think that's correct. If the timing was off this problem would happen all the time, not sporadically.

Intermittent problems like this are difficult to troubleshoot unless it happens at a diagnostic shop that has equipment to track it down.

lexusk8

It's a little hard to pinpoint the exact problem to your start-up issue, but you may want to look into the possible causes that are easy to detect and less involved, such as:

- Bad gas (consider switching to premium if you haven't already)
- Dirty fuel injectors (insert bottle of fuel injector cleaner fluid into the tank)
- Air filter (replace if dirty)
- Check battery life and connections
- Check spark plugs and see if they need to be changed (should be replaced every 60K IMO)

There are other probable (and less obvious) causes to your start-up problem, but for now, I would consider the above options. Let us know what you can make out of. Get assistance from a mechanic friend if need be, and good luck

flipside909

No like engine timing i.e. spark plugs and tune up. Like what was mentioned above, it could be as simple as those. I've seen this symptom on some cars and it's usually electronics (timing related) or even emissions system related like the sensors. It looks like you have a K&N installed on your ES. You may want to check the air filter and possibly see if oil/dirt has collected into your MAF sensor.

timoc42

hey guys,

thanks for the responses.
this is what i've done.

i've just put in an STP fuel injector.

i've just cleaned up my K&N filter using the recharger.

i just put in Sunoco's 94 Octane, instead of the Mobil 93 that I always use.

I think my spark plugs were changed just 10k miles ago, so that shouldn't be a problem.
Battery was also changed with original Lexus battery at the dealer on March. I checked
connections too... so, shouldnt be a problem too.

So, i'll update you guys on whats happening. I mentioned this to the mechanic, and since I
cant reproduce this problem while at service, they dont know whats wrong.


Thanks

Tim

flipside909

Good luck. BTW, I hope you meant STP fuel injector cleaner?