Car starts at 2,000 RPMs and then drops with warm up to normal idle?

MAXVAS

MEMBER
2005 TOYOTA CAMRY
2.4L
4 CYL
2WD
AUTOMATIC
128,000 MILES

After cleaning the throttle body at start it has 2000-2200 rpm, which decreases 3 seconds to 1,500 and then gradually decreases to the normal 670-700 RPMs. Before that, at startup, the maximum rpm was about 1,500-1,600. Sometimes (it was about 3 times) after jumping to 2,000 and dropping to 1,500, stay at 1,500 and go up to 1,800 and go down again with warming up. No check engine light.

Perhaps these are independent things, however, it also seemed strange the low flow rate through the MAF of 2.1 g/s at idle (approximately 700) and about 7 g/s at 2,500 rpm. Long term fuel trim +5%. Also, the car hesitates under load. For example, when driving uphill when it is 1,100-1,300 RPMs and accelerate, I have to increase the RPMs to 2,000 and then brake to keep the distance between the car in front. This has been observed before and may be the result of something else.

9 Replies

JACOBANDNICKOLAS

MECHANIC
108,269 POSTS

Hi,

Do you have the short-term fuel trims as well? That may help.

As far as the issue, first, make sure there are no engine vacuum leaks. That can have an adverse effect on the idle speed.

If that checks good, make sure there are no restrictions in the intake or exhaust. The idea that you have a hesitation leads me to think there could be a vacuum leak. Also, since the LTFT is +5, that tells me the computer is trying to add fuel most of the time. So, that also could indicate a vacuum leak.

Here are a couple of links you may find helpful:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

https://www.2carpros.com/articles/engine-hesitates

Keep in mind, the issue could be related to the throttle control motor itself. I don't believe it is serviceable on this vehicle. I attached diagnostics for basic testing below.

Let me know if this helps or if you have other questions.

Take care,

Joe

See pic below.

Image (Click to make bigger)

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Wednesday, May 3rd, 2023 AT 7:17 PM

MAXVAS

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First of all, thanks for your detailed answer.
I will double check all hoses, MAF o-ring and air filter this weekend. I will also diagnose the throttle body according to your procedure.

To have a complete picture, I collected all the data with a scanner from a warm engine after driving. I want to note that this time Short/Long term fuel in total give a value close to 0 (even a little minus). MAF has the same low values of about 2.1-2.2 g/s. O2B1S2 values could not be fixed because they are constantly changing in the range from 0.15 to 0.81 (attached graph).

DTC_CNT 0
FUELSYS1 CL
FUELSYS2 N/A
LOAD_PCT(%) 13.3
ECT(°C) 93
SHRTFT1(%) 0.8
LONGFT1(%) -2.3
RPM(/min) 670
VSS(mph) 0
SPARKADV(°) 15
IAT(°C) 30
MAF(g/s) 2.15
TP(%) 14.5
O2S B1S12--B2S----
O2B1S2(V) 0.175
OBD OBD2
EQ_RATB1S1 1.004
O2B1S1(V) 3.288

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Thursday, May 4th, 2023 AT 6:03 PM

JACOBANDNICKOLAS

MECHANIC
108,269 POSTS

Hi,

What was the outside (approximately) when you scanned it? The IAT seems a bit cool. However, that may be correct if it is cooler where you are located.

Let me know.

Joe

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Thursday, May 4th, 2023 AT 7:22 PM

MAXVAS

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5 POSTS

Hello, it was about 50F (10C) when I took the reading. I was able to check the throttle position sensor so far, which showed 76.5% > 60% in the fully open position.

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Friday, May 5th, 2023 AT 6:36 PM

JACOBANDNICKOLAS

MECHANIC
108,269 POSTS

Hi,

That wouldn't cause a high idle. Also, the intake air temperature sounds normal based on outside temperatures.

Have you had a chance to check the throttle control motor?

Let me know.

Joe

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Saturday, May 6th, 2023 AT 6:59 PM

MAXVAS

MEMBER
5 POSTS

Hello. Returning to my question, I checked the sound of the throttle body and it seemed to me squeaky, as if a butterfly clings to the walls (I'm not sure if this is still a normal sound and I recorded a video). Therefore, I decided to clean it again (video before it) and at the same time check the hoses. The hoses that I disconnected (as well as the PCV one) were intact and without cracks. I also checked the brake booster for leaks (using Toyota service manual), it was also good. I didn't have the opportunity to ride and give time to calibrate, so I don't know if a second flush helped. So far I've seen the same behavior.

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Sunday, May 7th, 2023 AT 4:33 PM

JACOBANDNICKOLAS

MECHANIC
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That is a little noisier than I would expect. How are you actuating the throttle control motor? It may be the motor itself that is causing the problems.

Let me know.

Take care,

Joe

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Sunday, May 7th, 2023 AT 9:40 PM

MAXVAS

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During cleaning and checking throttle body sound, motor was driven by the accelerator pedal in the "on" position of the key.
Thanks

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Monday, May 8th, 2023 AT 6:17 AM

JACOBANDNICKOLAS

MECHANIC
108,269 POSTS

Hi,

I just wanted to confirm that. It shouldn't be making that squeaking sound. You may need to replace the throttle control motor if the problem isn't resolved by cleaning. It sounds like something is rubbing which could be why the idle is high for a period of time.

Let me know how things turn out for you.

Take care,

Joe

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Monday, May 8th, 2023 AT 6:30 PM