11
votes
Accepted
How to trigger an idle throttle position re-learn?
I know this vehicle as a Yaris; 1NZ-FE engine, and that is the vehicle I am commenting on.
Toyota does not mention a specific procedure for an idle relearn in their official service information.
...
- 11.6k
7
votes
2005 Honda Accord 4cyl revving idle when warm
You need to check for leaks in the air intake
A leaky air intake can explain hunting idle and I don't think spraying carb cleaner is always conclusive as some cracks can be really hard to see/detect.
...
- 39.1k
7
votes
My BMW 325xi smells like gas
The fact that you can smell fuel in the exhaust is a strong indication that the engine is running rich.
This means that there is more fuel than required by the engine. There are many things which ...
- 39.1k
7
votes
Solstice! Car starts to run rough after hitting the gas, intermittently.
Regarding the tangent, yes, an ill-fitting dipstick can be the cause of a vacuum leak.
Pulling out the dipstick is a way mechanics can figure out if the car is suffering from unmetered air/vacuum ...
- 39.1k
6
votes
Accepted
Rough Low Idle and Engine Shakes, Hesitation and Lack of Power
So I finally figured out the problem.
First off I had a defective O2 / Lambda sensor, which I replaced. However, this had little or no noticeable effect on the problem. The valve cover gasket was ...
- 15.7k
6
votes
Is it healthy to drive with a bad IAC?
This wont do any damage to your engine until you have an accident making a mistake with the pedals:) The IAC would only doing the same function that you are doing manually. I do think you have more ...
- 24.8k
6
votes
Startup problems: low idle RPM and stall on pressing the accelerator
Not familiar with your vehicle/engine specifically, but familiar with carbed engines in general.
I would think the #1 thing to look at would be the choke. Pumping before starting a carb vehicle is ...
- 8,443
6
votes
Accepted
2015 Honda Mobilio - Car shakes when started
If I had to guess this sounds like a four cylinder engine, with one or even two cylinder's misfiring. Best guess is a problem with either a spark plug wires, or an ignition module. I'm looking at ...
- 6,569
6
votes
1996 Chevy K1500 Silverado ZZ4 5.7L - Rough Idle, Plug Damage, Overheating, EGR
I see the following possibilities:
Like dlu said: wrong range of spark plugs. Perhaps you can try some colder ones. When trying this: be sure to check the spark plugs soon, a too cold spark plug ...
- 8,448
6
votes
Accepted
Rough Idle & Stall While Stopped
I would check the idle air control valve, or the IAC.
This might likely create the exact symptoms you describe. Determining if it's working properly is a bit of a chore for a DIY person, but this is ...
- 12.4k
5
votes
2001 Infiniti QX4 rough idle - leaking fuel damper vacuum port
Thanks for the great detail. Considering this is a bit of an odd issue, I'll try thinking outside the box a little. But first I would use a multimeter to test the coolant temp sensor, then o2 ...
- 898
5
votes
Accepted
2005 Honda Accord 4cyl revving idle when warm
My suggestion is that your IAC valve is sticking. This would mean it is jutting in/out and not providing the amount of air for the computer to get the engine to settle. Since you've already cleaned it ...
- 153k
5
votes
Engine hesitates and stalls when warm
The stalling issues point toward problems with an engine control system (air, fuel, or spark), but again short of replacing the fuel pump, you have already replaced the parts most likely to cause ...
- 6,037
5
votes
Accepted
08 Silverado 5.3 rough idle and dark cold start exhaust
First of all, the 5.3l engine (could be all of the Vortec LS engines, don't know) is thirsty. It drinks a bit of oil. Be aware you could be looking at up to 2 quarts between oil changes. I don't know ...
- 153k
5
votes
Accepted
Rough idle + slow acceleration + engine dying after spark plug change
Probably not. Engines are pretty tough. But pull a plug before you drive anymore and check for mechanical damage. Pistons hitting plugs would not be good.
Also double check your plug wires and make ...
- 14.4k
5
votes
Accepted
Engine's RPM drops right after start and after letting off the gas
Sounds like trouble with the idle speed control valve. On the '93 Miata, it looks like this:
This little guy, when working properly, will let enough air into the engine to keep the engine alive when ...
- 12.2k
4
votes
Accepted
RPM bouncing when in idle, especially when AC in switched on
The exact cause of the issue had been found to be that of a loose alternator belt.
When the engine was cold, the alternator had a slack in it and if the AC load is added on the engine, the rpm ...
4
votes
Accepted
My Ignition Timing is Retarded, no seriously, it's really screwed up
You probably need a new lambda sensor. Here's why:
You're right - the lambda sensor needs to reach a certain operating temperature to function properly. Until it reaches that operating temperature, ...
- 39.1k
4
votes
My Ignition Timing is Retarded, no seriously, it's really screwed up
Good example of PID graphing.
Consider the possibility that these symptoms are caused by a mixture issue instead of timing. The STFT is adding fuel and the symptom of hesitation further suggests ...
- 11.6k
4
votes
Is it healthy to drive with a bad IAC?
As HandyHowie said, this won't cause any damage.
However, there is a better way, based on the assumption that you have a foot on the brake because you leave the car in D at the lights. If the car ...
- 781
4
votes
Rough idle + slow acceleration + engine dying after spark plug change
Don't worry about engine damage. The main difference between these 2 spark plugs is the length, the one you used is shorter. That means 2 things:
the spark was not created in the best place, meaning ...
- 12.2k
4
votes
1996 Chevy K1500 Silverado ZZ4 5.7L - Rough Idle, Plug Damage, Overheating, EGR
My first thought here is to tackle the problems methodically, one at a time.
The one that sounds most significant to me is the plug 5 damage – from what you've said it sounds like detonation (aka ...
- 14.4k
4
votes
Astra MK6 - when warm, rough idle and shudders while accelerating
I don't know that particular car well, but maybe a vacuum leak? Perhaps it's at the intake manifold, and worsening as the parts warm up, expand, and mating surfaces change shape?
- 41
4
votes
Car engine vibrates vigorously with air conditioning on at idle speed
I'll take a swing at this ...
The engine in your car, whether it's the Single Overhead Cam (SOHC) or Double Overhead Cam (DOHC) version, has a vacuum actuated (non-electronic) idle air control valve. ...
- 153k
4
votes
4
votes
Timing sounds off, how do I confirm this?
When changing the timing belt, it is the valve timing that can become displaced if the belt is not put back in the correct position. To accurately check this is a simple visual check. However, to do ...
- 24.8k
3
votes
Accepted
Rough idle when AC is on
The symptoms are consistent with deposits in the throttle body. There are other potential causes. These deposits accrue in the intake manifold over time. They build faster with short trips and low ...
- 11.6k
3
votes
RPM bouncing when in idle, especially when AC in switched on
Or could be your mass airflow sensor because I have similar issues and that is what's wrong with my car
- 31
3
votes
Citroen C4 - Poor idle and low rev performance?
Apparently it was diagnosed by a specialist that there is a hardware / software problem with the ECU (Magneti Marelli) that is causing all this problems, and needs to be changed. There is nothing ...
3
votes
Rough Low Idle and Engine Shakes, Hesitation and Lack of Power
This may well be the smoking gun
That "grommet" is actually a fuel injector seal. It is designed to keep air out and prevent fuel from escaping the intake manifold.
If it is compromised then fuel ...
- 39.1k
Only top scored, non community-wiki answers of a minimum length are eligible