Check engine light - throttle problems

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epj3

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Every time i start my car now, I get a check engine light and, even though it idles decent, when I go to give it gas, even Wide open throttle, the car doesnt do anything except it will accelerate VERY slowly and very unsmooth for about 10 or 20 seconds... After that it will run absolutely fine.

I had the hood up obviously wandering WTF is this check engine light for... and when I would have the car off and turn it to run (NOT starting it) a relay clicks 3 times that I have never heard before... could this relay be effecting the fuel flow to my cylinders? I THINK there is a relay that controls the difference between any throttle, and idle (since when you use the pedal there is a throttle position sensor to measure the fuel -- idle it's a computer adjustment)

Anyone have a clue? Or do you think I pinpointed my problem?
 
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nadroj

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there is a way to check you CE light, if you have a bently or any other type of repair manuel it should tell you how to check it, my chilton manuel did.
 
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epj3

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nadroj said:
there is a way to check you CE light, if you have a bently or any other type of repair manuel it should tell you how to check it, my chilton manuel did.
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I'm thinking it might be the cold start valve. The bently manual says that it has an electric current that will heat up to close the cold start valve to prevent engine flooding in case the valve itself fails.

If the engine is getting way too much fuel I think it could be getting these symptoms.
 
xLibelle

xLibelle

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Sounds to me like your O2 sensor could be going. (Hunch - i had the same thing b4)
The car can still run ok, but the computer still knows the sensor is going.

You need to check the codes by that brake peddal thing, i forget the sequence.
Turn the key to ON and depress the brake like 4 times and the codes will blink on the console. Should be easy enough to find the meanings online.
 
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epj3

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xLibelle said:
Sounds to me like your O2 sensor could be going. (Hunch - i had the same thing b4)
The car can still run ok, but the computer still knows the sensor is going.

You need to check the codes by that brake peddal thing, i forget the sequence.
Turn the key to ON and depress the brake like 4 times and the codes will blink on the console. Should be easy enough to find the meanings online.
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I dont think that's it -- after like 10 seconds the car runs absolutely fine, has no weird smells from the exhaust and my gas mileage is fine.

I still think it's the main relay for the injectors and fuel pump, when i turn the key to on it makes those 3 clicks that i have never heard before. I'm going out to check codes right now.
 
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epj3

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Blinked twice -- Bently says "Oxygen sensor faulty or fuel mixture too lean or too rich, due to faulty fuel or ignition system components causing oxygen sensor to exceed its operating parameters"

I hope i dont have a vacuume leak, but an oxygen sensor isnt that big a deal.
 
xLibelle

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epj3 said:
I still think it's the main relay for the injectors and fuel pump, when i turn the key to on it makes those 3 clicks that i have never heard before. I'm going out to check codes right now.
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hmm, sorry i missed that description.
Is it that its after cold start only?
 
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epj3

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xLibelle said:
hmm, sorry i missed that description.
Is it that its after cold start only?
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Nope, used to be but now it's all the time. It seriously hesitates after every start even w/out a check engine light. Still hear the relay but the check engine light came on for the "Oxygen sensor faulty or fuel mixture too lean or too rich, due to faulty fuel or ignition system components causing oxygen sensor to exceed its operating parameters"

I'm thinking that it IS that relay, and that the reason the check engine light came on is becuase not enough fuel is being delievered to the engine due to the faulty relay.

Are relays expensive?!?
 
jrt67ss350

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epj3 said:
Nope, used to be but now it's all the time. It seriously hesitates after every start even w/out a check engine light. Still hear the relay but the check engine light came on for the "Oxygen sensor faulty or fuel mixture too lean or too rich, due to faulty fuel or ignition system components causing oxygen sensor to exceed its operating parameters"

I'm thinking that it IS that relay, and that the reason the check engine light came on is becuase not enough fuel is being delievered to the engine due to the faulty relay.

Are relays expensive?!?
Click to expand...
Relays can be expensive - it all depends. If you have to get a BMW one, it may be pricey - I know the relay that runs the interior dome lights is like $80-$90 for a stupid relay. You may also be able to get a more generic one at an autoparts store - it all depends on the relay. You could maybe try removing the relay and carefully jumping the relay plug to see if that stops the hesitation after carefully studying the wiring diagram.
 
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epj3

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jrt67ss350 said:
Relays can be expensive - it all depends. If you have to get a BMW one, it may be pricey - I know the relay that runs the interior dome lights is like $80-$90 for a stupid relay. You may also be able to get a more generic one at an autoparts store - it all depends on the relay. You could maybe try removing the relay and carefully jumping the relay plug to see if that stops the hesitation after carefully studying the wiring diagram.
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Well, it is the relay that controls the fuel ignition system -- it's not in the fuse box but in front of it.

It's a white relay closest to the front of the car
 
jrt67ss350

jrt67ss350

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Yeah, I know which relay you are talking about, but I don't know if you'd have to get one from BMW to replace that or not. It all depends if you can find a generic one at an autoparts store that has the same plug pattern/switching and appropriate current ratings.

You may want to try bypassing the relay with a jumper wire to see if it fixes your problem before investing the time to track down a relay.
 
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epj3

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jrt67ss350 said:
Yeah, I know which relay you are talking about, but I don't know if you'd have to get one from BMW to replace that or not. It all depends if you can find a generic one at an autoparts store that has the same plug pattern/switching and appropriate current ratings.

You may want to try bypassing the relay with a jumper wire to see if it fixes your problem before investing the time to track down a relay.
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also how much would an oxygen sensor cost? i think i've seen them for like 90 bucks online. Fun stuff to diagnose, isnt it [8)]
 
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