98 V6 starts but can't keep idle and dies

[ftmail]

Ocassionally, my car would not start up. The engine starts up but it does not hold the idle and and it dies immediattly. This happens 5 to 6 times a year, but when it happens it would not work even if I try 20 times. The car has about 90K miles and the check engine light is not on.

The only way to start it, is to press the left foot on break and in the same time lightly push the gas with the right foot... it is crazy, but this is the only way to keep the engine at about 800-1000 RPM . Then, I can put the car in gear, release the break, and the the car starts moving. After the car reaches about 20-30 mi/h, I don't have to keep the idle (with the right foot) and I can drive normally. If I stop the car within 1-2 minutes, the car has the same problem. However, if I run the car over 30-40 mi/h and it gets to shift to higher gears, the car works normal and even if I start it, it will re-start normally.

[Eye8Pussies]

I would check a number of things...

check your maf sensor, and also check your iac

[toyomoho]

If you can start the engine by using the throttle pedal check the MAF sensor.

[ftmail]

I have the manuals on CD but could not find the Service Data and the way to check the MAF. For a Camry, I could find that the resistance for the MAF sensor should be 2-3K Ohms@68 F and 0.9-1.3KOhms @104F.

Any idead how can I find the correct values for a ES300 ?

[Eye8Pussies]

the camry and es300 maf is the same thing if they are the corresponding generation

check the resistance, but also just try cleaning it with electronic cleaner as well

[marc780]

The other people posting have some good ideas i will add to some of them on what i would do if i had this problem (as i have on other cars in the past)
1. clean throttle body butterfly and inside TBI. Search posts here there are several good ones on how to do this easy job. Also make sure to spray a lot of tb cleaner inside the Idle Air Control valve if it has one (although i dont think the V6 does).
2. Inspect vacuum hoses for misrouted, missing, displaced or cracked vacuum hoses causing vacuum leak
3. check PCV valve - pull it from its hole, shake it and listen for a rattle. If it rattles it is ok, if not, change it
4. The inside of your throttle body could be worn out from the butterfly touching it alot, especially if you own a manual shift car -
5. If i understand clearly what you write, it sounds like you have this idle problem with the engine hot or cold. So it isnt a thermo sensor/switch or something. it is in the idle system.
Download the factory manuals in adobe and follow some trouble shooting steps if none of the above resolve the problem for you...please post back when you fix it, im interested in what the fix turns out to be!

[ftmail]

First of all, thank you everybody for the very good feedback they send. However, I need to leave for a business trip out of state for about 2 weeks, but as soon as I get back, I will work on the car and update everybody on how it went.

[marc780]

so ftmail what did the fix turn out to be?

[97&02camryleI4]

My best bet is the IACV. I had the same exact problem. Cleaning it will only be a temporary fix (2-3 months) so it would be best to replace the entire IACV assembly. It should cost $200 just for the part from the dealer. I have already replaced mine twice. First was at 25k then at 60k.

[ftmail]

I put some FUEL INJECTOR CLEANER in the gas tank about 3 weeks ago and was hoping this would "fix" it. I was trying the easy way out because I was not to sure how to do the other suggestions which seem more complicated for me.

However, the problem re-occured again yesterday, and the car did not keep idle. With the right foot on the gas to keep the idle at about 1000 RPM, I was able to start and then after driving it for about 1 minute about 30 mi/h, I stopped the engine and then restarted without problems. My car is automatic and the engine light is not on.

I printed all the suggestions and do the easier ones first and then wait for about a month or two.
Ussually this problem happens every month or two.

Here are the next steps I plan to follow:
1) use a can of carb cleaner to clean the idle air control valve which can get stuck. I think that this is the same as "clean throttle body butterfly and inside TBI" (hopefully I can find it in the car manual)
2. Inspect vacuum hoses for misrouted, missing, displaced or cracked vacuum hoses causing vacuum leak
3. check PCV valve - pull it from its hole, shake it and listen for a rattle. If it rattles it is ok, if not, change it
4. Check the inside of throttle body which could be worn out from the butterfly touching it alot
5. check the MAF sensor (again, I hope that the car manual has a clear description as I have no idea what this is and where I can find it...)
6.replace the entire IACV assembly which is about $200

[marc780]

replace the entire IACV assembly which is about $200

Chances are there's no reason to do this, if a thorough cleaning doesnt fix it right up, get one from a pick-your-part junkyard and save about 90%. Plus you can clean it real good first before you put it on. To check just hook up the electrical connectors without installing it, start the engine and watch for the vanes to open as engine warms. In fact to speed things up you can just hook it up to a warm engine. If the vanes move this used IAC is good.

[97&02camryleI4]

Originally Posted by marc780

Chances are there's no reason to do this, if a thorough cleaning doesnt fix it right up, get one from a pick-your-part junkyard and save about 90%. Plus you can clean it real good first before you put it on. To check just hook up the electrical connectors without installing it, start the engine and watch for the vanes to open as engine warms. In fact to speed things up you can just hook it up to a warm engine. If the vanes move this used IAC is good.

The reason I suggested to replace the IACV completely with a new part (if that's the problem) is because cleaning it will only be a short-term fix before one will have to take it off and clean it again. I know because I've done this several times already. My first one went out around 25k and I tried to clean it with carb/throttle body cleaner after I took it apart. Let it dry for a few hours and then stuck it back in. Worked like a charm, but the next month, it started to stick again. So it was replaced with a brand new one and has worked until 60k where I tried cleaning again but cleaning is again, a temp fix. You can go ahead and buy a used one and save some money like what marc780 suggested but a brand new one would definitely last longer and save you time from dealing with it for another 30-40k.

[ftmail]

After reading the 97 Lexus ES 300 manual, I have a few questions:


(1) The SFI manual warns that “to prevent deterioration, do not clean the throttle possition sensor and IAC Valve”. I have bought a “throttle and air intake cleaner” spray and was wondering if the is ok to use it on both of them ?
Can the solenoid (step motor) be damaged by the cleaner ?
Should I cover the throttle possition sensor so that the cleaner does not get to it ?


(2) According to manual and by quickly looking at the IACV, it has 4 screws underneath, which seem impossible to remove without removing the whole throttle body first.
Did anybody remove it without taking out the throttle body ? See pics of the IACV for 97/98 1MZFE engine – but I looked at my friend’s 94 Camry and it looked exactly the same:

http://replacement..com/parts//quote.jsp?year=1998&product=C4030-150368&application=000788353&part=Idle%20Control%2 0Valve&dp=false


(3) The IACV has a plastic part which houses the solenoid and this can be removed by two front screws without removing anything else. Is it safe to remove the solenoid ?

In a recent Lexus forum I found the following post:
“In the process of cleaning the IAC valve, I disassembled the electronic coil part from the IAC body, when reassemble, I noticed the valve window (opening) has changed (larger), and the initial engine startup idle raise to 1500-2000 (cool engine). When it warned up, engine idle at 900 instead of 700.”


(4) Do I need to buy the throttle body and IACV gaskets before starting to take things apart or these are re-usable parts ?

(5) What it TBI ? Throtle Body ... ?

[marc780]

The reason I suggested to replace the IACV completely with a new part (if that's the problem) is because cleaning it will only be a short-term fix before one will have to take it off and clean it again.

Well sounds like your engine has a little bit of oil blow-by from the rings and valves - no big deal (even brand-new engines have SOME blow-by), so dont worry about it if it runs well, doesnt use much oil and passes smog.
If the old one clogged fast so will the new one, may i suggest something, just plumb in a clear cheapo plastic fuel filter from the auto parts that cost maybe $4 at the most. Plumb it into the vacuum line that goes to the plenum/manifold. If you do maybe your TB will stay cleaner for a longer period of time -

[ftmail]

I finally decided to start working on the iac cleaning job after a friend at work told me that he replaced the transmission on his Ford Astro in 3 hours with some help from one if his body... If he coud replace a transmission I should be able to clean the iac...

I was able to remove the three hoses connected to the iac. Then I removed the 4 screws from the TB and cleaned it well with throtle body cleaner although I think that it was not too dirty.

Then, I was able to rotate the TB so that I can access the 4 screws underneath and I removed 3 of the 4 screws. I got stuck with the last one and I am attaching a picture of it and see if anybody has some sugestions. I used some break loose spray and let it rest for right now...

I took some pictures and will post the rest of them after ai finish and write some "how to for dummies" .

Here is the infamous screw...[IMG]C:\ft\cars\Lexus ES300 1997-2001\pics\iac_throtle_body\DSCN5035.JPG[/IMG]