Hello all. I recently replaced the coolant reservoir. About a week ago. The car has been driving great then today, after driving around in the morning with no issues I start the car to go somewhere and the idle is around 1000 and there is no throttle response. Push the throttle peddle and nothing. Keep doing it and it kind of starts revving again.

Now on I get this idle surge after I removed the throttle body and gave it a thorough cleaning and also cleaned the MAF.


Any ideas would be appreciated.

Thanks!

 

How did you clean the MAF? The ABS, PSM lights are a possible symptom that it's not functioning properly now.

 

Hello Mark. I used CRC Mass Air Flow Sensor Cleaner that I got at OReillys. I forgot to mention that the idle surging is after starting the car. On previous starts before the idle surging started it was a high idle. I don't know if that helps or confuses the issue.

Is there an idle control valve or is it integrated into the throttle body? I'm thinking the weird behavior that I had, high idle and no throttle response, then just high idle and now surging idle is because the throttle body progressively got worse? I haven't driven it since this has started.

Can you please explain how the MAF can affect the lights that came on?


Thanks!

 

Another thing. I disconnected the maf while the surging idle was happening and the surging stopped. It just idled low and rough but surging stopped. When I start up the car, it does the initial rev surge as normal but then the revs drop really low and then the engine catches that and increases the revs again and the surging cycle starts. Its like whatever controls the idle speed is now broken and set too low and the other other parts of the engine kick in to stop the engine from stalling.

What controls idle in these cars since there is no Idle Control Valve. I'm thinking my throttle body or MAF sensor is dust. Any procedures out there to test those units?

Thanks!

 

Have you tried e-gas recalibration? Engine off. Turn key to last position before crank and leave it there for 60s. Foot off the gas. Turn key off and wait for 10s then you're done.

 

Here is a video I took before I saw Ahsai's post.


That must be what is was because I must have inadvertently did that reset as the car fixed itself!

Thanks for all the help!

Any idea what causes things to go out of whack necessitating this recalibration?

On to alternator fix!

Thanks again!!

 

After you disconnect the throttle body, it may need recalibration.

 

Glad Ahsai got you sorted out on the surging issue. He's definitely the resident brain trust on most such things. I was concerned you may have physically molested the MAF sensor, which is integrated in the PSM circuitry. When it fails it can trigger the PSM and ABS lights which flashed in your earlier video. GL with alternator fix. Don't know what problems you're having, but bear in mind that it's often the voltage regulator, which is a fairly simple an inexpensive fix (numerous threads on that) vs. replacement.