Laszlo Kovesdi

Does anyone know how to fix this problem?

At 1:49 seconds, the engine starts revving for about 3 seconds and then levels out. The engine runs like a champ. Nothing wrong if the engine when it warms up like this. The only problem is if I were to start the engine, and drive off before it warms of properly(like above in the video), the engine rpm would stays around 1k rpm or above. It sputters while driving and the engine light comes on saying "increased emissions". A restart of the engine fixes this problem and the check light goes away from a couple of restarts. Also, every so often, the engine does start with high rpm throwing it into those conditions when not warmed up correctly. An engine restart fixes that too.

BimmerFan52

You might start by looking at your battery and then alternator voltages.

One of the adjustments made by the DME when voltage is low is to increase the engine idle. Also turning the ignition off and then on, which clears faults is very commonly system voltage problems.

Auto stores will test your battery and alternator for free.

Laszlo Kovesdi

Well I guess no need for the test because my battery is bad. Ive needed a new one for a month now but pushed it back. Ill replace it tomorrow and Ill get back to you. Thanks man!

turboawd

i'd bet you have a bad oxygen sensor. the oxygen sensors take a minute or two to warm up and activate on cars. so when yours heat up and activate, its probably telling the computer the wrong air fuel ratio, hence the increased fuel, rpms, and sputtering.

Laszlo Kovesdi

Thanks Ill get to that if the battery doesn't resolve the issue. How much is a oxygen sensor and how much to replace it?

Laszlo Kovesdi

So brand new battery and it didnt fix the cold start revving. But it fid fix a few of my electrical problems. So thats sweet. So onto oxygen sensors..

Laszlo Kovesdi

So here are the codes I just pulled..

2820 Failure DISA
27B8 Plausibility Diff. Pressure Sensor
277C ECU Self-Test Reset
2783 Hot Film Air Mass Meter
2821 DISA Temp. Warn Level Engine Protection Model
299B Communication DME1BS

Any one have an idea?

545iMike

The Disa errors are because of oil gummed up in the intake manifold putting stress on the Disa motor. So you can eliminate those. I have the same codes, 2820 and 2821.

turboawd

they're not cheap, and usually there are several on the car.


with those codes you pulled, i'd investigate the MAF sensor. maybe try cleaning it and see if it helps.

Laszlo Kovesdi

Cleaned the MAF sensor and no change.

And Mike, If I clean it. How do I prevent it in the future, or I just clean it every so often?