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Discussion Starter · #1 ·
So I'm still having this slow acceleration problem after 2 years. Up until now its been really infrequent so I've been able to live with it.
Basically when I go to start the car, it stumbles and takes an extra second or two to turn over. usually a warmer than cold start triggers this but recently its been happening on cold starts. After the car stumbles to life, it accelerates very slowly. It basically bogs down when I hit the gas and I get almost no acceleration response. Its really dangerous to drive. Occasionally I am able to work around this by turning the car off and on a few times until I get a good clean start. The OBD sometimes spits out the code: P0340 which is the CPS malfunction. In order to combat these symptoms I have done the following:

-Changed the CPS
-Changed the Pre-cat 02 sensors
-Rebuilt the VANOS using Beisan seals
-Changed the air filter
-Changed the fuel filter

The issue persists and I am now leaning towards replacing CCV :dunno:. Does anyone have any other thoughts on this? Please Help!
Thanks in advance!
 

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Are you still getting the CPS code? Have you checked the spark plug wells for oil?

Test the CCV valve thus: hold your hand over the oil fill hole while the engine is idling. You should feel a very slight vacuum. If none, or very high vacuum, the valve is bad.
 
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Discussion Starter · #3 ·
Yes, I do still get the CPS code ocasionally but it seldom throws the code compared to the amount of times the car starts funny and the acceleration bogs down. I will try the thumb test tonight as well as check the wells again for oil. The last I checked they were oil free as I replaced the valve cover gasket when I did the VANOS refurb. Thanks for the info on the CCV.
 

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Occasionally I am able to work around this by turning the car off and on a few times until I get a good clean start.
It basically bogs down when I hit the gas and I get almost no acceleration response
Sounds like rich air low fuel mixture,
Check fuel pressure on rail under engine cover, it could be bad fuel pump

Right now i'm having same problem, but not years, it started to die few days ago, and now it died. I'm trying to repair it, or will replace with new one.

Also:
Check brand of CPS, if it's not genuine BMW it will not work.
CCV and CPS does not give such more power you expect. Go with new SIEMENS VDO MAF (250$), or hyundai 2.5 sonata v6 1999-01 MAF(150$)
 

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Discussion Starter · #6 ·
I just read the old order for the CPS. It was made by EKON. Have there been problems with this brand of sensor? I thought this was an OEM supplier, maybe not? The BMW branded sensor is $121 vs. EKON which was ~$70. Can these sensors be tested?
 

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EKON which was ~$70
Yes your new "bacon" sensor is faulty out of the box, return it and replace with oem one.
By the way, after you check pressure on rail under engine cover, check/replace (FPR) Fuel Pressure Regulator
 

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CPS: Kind of a rule of thumb... When you replace parts that go on the engine, stay with OEM, unless you KNOW, and it is a COMMON KNOWLEDGE that a specific non-OEM brand is better for some reason.

So a good CPS needs to go there. Yes, a bad CPS will give your limpy car. It will also stall on you when you do stop and go.

Other than that, what you have is a classic vacuum leak.

Do this test: Disconnect the plug that goes into your MAF, and see if your problem goes away.

Turning the key off and on again until the car "catches" a good start and a good idle - That's classic vacuum leak or CPS.

So for a vacuum leak you need to replace all the hoses around that CCV thing. The CCV might still be good, but since you're already there, replace it as well.

mw
 

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There are a number of vacuum hose's that can develop leaks and cause the engie to lose power--vac leaks wreck havoc on fuel metering--check the air intake where it hooks to the idle control valve as well as clen the idle control valve--by all means replace the cam position sensors with the OEM parts--I would look to
EACtuning--one of the vendors here--noted for good service and quality parts--they will set you up with
what you need at prices that won't break the bank.
 

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Discussion Starter · #10 ·
Ok, you have convinced me that I need to overhaul the CCV. I'm going to do one thing at a time in the following order and I'll report what fixes it:
1) thumb check dipstick
2) disconnecting MAF
3) CCV Overhaul/replace
4) buy another CPS and see if it works better

Interesting thing to note: Pelican Parts sells an "OEM" CPS for $58 and the "BMW" brand one for $121.75. Can one assume that "OEM" is just as good? If so, why pay the extra ~$63?

Part Number Description Price Add to Cart
12-14-7-539-165-M58 Camshaft Position Sensor, Intake [More Info] [view in catalog]
Brand: OEM
$58.00

12-14-7-539-165-M9 Camshaft Position Sensor, Intake [More Info] [view in catalog]
Brand: Genuine BMW
$121.75

Thanks again for the help
 

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Well, you may end up spending $179.75 to solve the problem. Many have had CPS failures when they used a non-BMW sensor.
 

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ccv? pelican?

ok , i bought the cheap pelican part, made by oem ...wt the effin ... the part is defective and im so disgusted , i dont even want to go thru the hastle of return and bla bla,
LESSON LEARN
always replace with factory parts , for some reason aftermarket doesnt do it for bmw .. picky lil biatchhhhhh.
well enjoy ur diy time..becuz its the same time u can b charged for at the dealership..including the arm n leg lol:mad:
 

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so with the cps codes........
be aware that if u have high miles 150k+ , maybe u should consider overhauling , replacing the chain + tensioners.... just a thought, especially if theres a ticking sound from valve tappings
 
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