Greetings All,

I've been looking through some of the previous posts on this but they seemed to be a bit different symptoms of my problem.

For the past few years my 95 ES300 would periodically stall or run very rough. It only seemed to do this when their was a larger increase in the temperature during the day. (I live in Minnesota and at night it might be 25 degrees and the day it might be 50 or so.) I do not have the problem when the car sits overnight though. It only seems to be a problem when the car sits for say 15 minutes to an hour or so. When I go to start the car it will sometimes just stalls or run rough for 10 seconds or so (when it runs rough it usually runs at 500 to 600 rpm instead of the normal 800 to 900 rpm.) Once when it would not start I unplugged the vacuum line from the fuel pressure regulator and then it started up fine (but this increased the RPM). I did not see any gas coming from the regulator vacuum line either. It's been getting worse over the past few years and especially over the past month or so. Any recommendations on what to check or what it might be? Also the car has about 110,000 miles on it.

Regards,
Chad

 

I have a similar problem when my car sits and the temperature rises. I'll go to start it and it will turn over hten stall. But if I give it gas it won't stall :| Someone told me what the problem was once but i forget....

 

Do you still have the same problem or has it gone away? Mine used to just run rough but now it stalls sometimes.

 

Beavis1,

There are a couple things you can do to see if there's any improved difference with your engine starting. One is to change the air filter if you haven't already. Recommended filter replacement is every 12K miles, but that depends on what kind of air environment you live in and/or drive through. The 2nd thing to do is to apply some fuel injector cleaner fluid into your car. I remember you mentioned that you unplugged the vacuum line from the fuel pressure regulator, and you saw some change with your RPM (temporarily). I would suspect that there must be some clogging somewhere between the fuel tank and the engine, hence leading to rough idle and possibly reduced gas mileage. For the fuel injector cleaner, I highly recommend the Techron bottle (made by Chevron) that you can find in any auto parts store. Probably the best in the market.

Good luck and keep posting your progress,
Doug

 

given that not much of the maint. history of the car was given, I assume you have looked at or replaced the obvious:
air filter (as mentioned, however I think every 12k is excessive. every 30k is more reasonable)
fuel injector cleaing (as mentioned)
PCV valve
spark plugs and/or wires
thorough cleaning of the throttle body and air intake hose (check here for air leaks/pin sized holes).This has been a common problem for Toyota

more involved areas to look at would be:
TB position sensor
idle air control motor
air intake temperature sensor


Just out of curiosity, are any codes popping up when the idle acts up?

good luck,
steviej

 

steve has it pinned pretty good but i would say an airfilter is not a cause maybe something to look at though
the throttle body cleaning is you best bet
why
when cold the car has a bypass for extra air
when warm it closes now if it idles rough it happens most times when air is being blocked from passing the throttle plate smoothly
if the car drives fine or even just a little gas then 98% you throttle nees cleaning as it is sufocating the engine
just undo the black hose to the engine from the air filter i think flat head screw driver
with the engine running you would have to slowly spray the tb cleaner while opening the throttle more and less cost about 4 bucks and 10 minutes or less

fuel injector cleaner will not work for this problem as the injectors are after it
wal mart does this as part of a package of fuel cleaner tb cleaner and vacum manifold cleaner
about 30 it is actually really good and all they do is loosen the same as above and the brake booster line in 30 minutes but the cleaner should work very easily

good luck
drop me a line if you need help

 

Thanks All, I'll give these a try. I assume by TB cleaner you mean throttle body cleaner? Does brand matter for this?

Also I don't think it's tripping any codes since no lights come on.

Chad

 

make sure you read the ENTIRE label. Get the one that says "safe for O2 sensors".

sj