Need Help :Camry hesitating on start

[coolguy004]

Hello,
I have a 1998 toyota camry with approx 175xxx miles on it.
I read the DIY on cleaning the throttle body.
I used a can of Throttle body cleaner that I got from Kragen.
( Cost me approx $5.)
I did not used a toothbrush to clean the butterfly valve but sprayed the contents in the small hole just adjacent to the butterfly valve.
As mentioned on start up I did see a cloud of smoke come out.
However the low idle did not go away.
I repeated the procedure over a period of time approx 1-2 months (intermittently : about once every 1.5- 2 weeks).
Now my car really hesitates while starting..it does start but after a lot of clicks and some sounds like somethings stuck/clogged.
Any ideas or suggestions are more than welcome.
Thanks,

[93celicaconv]

When the engine is fully warmed up, how does it run (at idle speed, driving in the city, and driving on the highway)?

[coolguy004]

Runs fine when the engine is fully warmed up, how does it run
at idle speed : fine No problem
driving in the city : fine No problem
and driving on the highway : fine No problem

[93celicaconv]

OK. Your initial post said your work in spraying the IAC valve (which is what that small hole adjacent to the butterfly valve goes to) did not result in the low idle going away. So I assumed you have a very slow idle speed at all engine temperatures. Sounds like your condition only exists when the engine is cold, right?

Is the check engine light on?

I would want to check your ECT (engine coolant temperature) sensor, the coolant sensor that sends resistance data to your ECU, so your ECU knows how warm the engine is. It is possible the ECT sensor is telling the ECU that your engine is always warm, so the engine is too lean on a cold start right now.

BTW, an ECT sensor that is no longer in calibration will not trigger a check engine light. An ECT sensor that is no longer connected to the wiring harness will trigger a check engine light though.

Do you have a digital ohm meter? If so, when the engine is cold, measure the resistance across the two terminals on the ECT sensor and let us know what the resistance value is that you get.

[fenixus]

also another question (per IAC valve functionality).

when you start engine cold, what RPM does the needle hit first ? 1,200rpm ? 2,000rpm ?
because when engine is very cold the IACV will shoot the engine speed up to 2k rpms to make it warm up faster and then will gradually lower the engine speed down to 700+/-50rpm at idle (all accessory off).

If on cold start needle doesn't go above 1,000rpm then the IAC valve may be sticky, to clean that I suggest using a can of Sea Foam Deep Creep spray and a toothbrush to wipe the edge of the hole (by throttle plate as you mentioned).

as 93celicaconv mentioned it might be as well caused by wrong readings from the ECT for EFI sensor, so ECU thinks your car is always warm. simply unplug the electrical connector from that sensor (at completely cold engine) and with multimeter set to Resistance measure the terminals.

at completely cold coolant temperature (close to ambient air temperature, e.g. ~70F in morning depending on your location) it should be reading around ~2k ohm (2,000 ohm).
the higher temperature gets the lower the resistance goes (down to 200-300ohm at fully warmed up).

is your engine 4cylinder or 6cylinder ?

[coolguy004]

Wow..read both the posts..so now I guess I have a little bit more work to do...for checking the ECT setting.
93celicaconv : I dont know anything about the ECT sensor? Where is it located and how do I do the test?
fenixus : I will also try to clean the throtle body with a toothbrush and the seam foam that u suggested.

The problem generally happens in the morning , the idle is either too low or about at 1700-2000 rpm. and once engine is warm the rpm comes down.

Specific question:
On the other hand is it possible that i can damage the IAC value by overspraying it with the throttle body spray cleaner?
93celicaconv and 93celicaconv any input/thought?

[93celicaconv]

Your ECT sensor is located on your water outlet housing - distributor end of engine. It will have a 2-wire harness connected to it.

You test it by removing the wiring harness to expose the 2 terminals within the ECT sensor that the wiring harness is normally connected to. Set your multi-meter to ohms, and using the 2 probes, contact both terminals and read the resistance. Fenixus has a good post on what to expect.

It sounds like a cold start on the engine doesn't always produce the same symptoms. Sometimes it runs faster (1700-2000 RPM), and sometimes slow (you didn't post what that speed is). When you start the engine cold, and it runs from 1700-2000 RPM, do you have any problems with hesitation then? Does the hesitation only happen when the engine runs slow on a cold start?

I don't think you can damage the IAC valve using cleaners, as the parts exposed to the cleaners are metal only (pintel and seat).

[coolguy004]

Actually there is no hestation while running , my car hesitates to start ,once started no problems at all...its only during ignition time when it hestates to starts
Its a 4 cylinder.

[93celicaconv]

Originally Posted by coolguy004

Actually there is no hestation while running , my car hesitates to start ,once started no problems at all...its only during ignition time when it hestates to starts
Its a 4 cylinder.

Ah, we have a terminology/interpretation difference going on here.

Most people think of an engine that hesitates as one that is running, but when the accelerator pedal is pressed a little, the engine fails to increase speed immediately, may even slow down a bit until it finally responds to the change and increases speed.

Ignition time is any time the key is in the run or start position, regardless if the engine is running or not, or if the engine is hot or cold. When the key is in the run position, the ignition system is enabled.

I don't think the problem is the ECT sensor anymore. If it was, it would lend to having a rough running engine when cold in addition to difficult starting (rough running due to too lean of Air/fuel mixture). You don't have the rough running engine once it starts, so I think that rules out the ECT sensor.

At this point, I would step back a bit and think about mechanical timing and cylinder compression pressures. Your cylinder compression pressures may be too low, and that could cause the difficult cold start issue, but allow the engine to run smoothly once it is running. Do you have an ability to check cylinder compression pressures?

Mechanical timing between the crankshaft and camshaft is also a possibility, but I would think it might also cause a noticeable change in how smooth the engine runs or how much power it has. Checking mechanical timing on a 5S-FE is a bit of a challenge, by how the engine sits in the engine compartment (no clear view through the camshaft sprocket to see the timing mark, unless a mirror is used). So this wouldn't be the first thing I would check.

How did your symptoms develop? Slowly over a long period of time? Or suddenly - worked fine up to one day, but the next, these symptoms were present and haven't changed much since?

[coolguy004]

Yes you have it correct , terminology is the issue :-)
Well this what I suspect, this problem of not starting/low idle in the morning has been there for a few years.
So I have used the post for cleaning the throttle body.
It did help however today morning while the ignition key was trying to start the engine, I heard a lot of cliks and chughs before the car started smoothly.
it did that a couple of time did not start and then finally started and now is not giving any problems while starting.I guess will have to wait till tommorow morning to xcheck if its a morning issue.
I have sprayed Throttle body cleaner but have not used a toothbrush to clean the butterfly valve.