[reflex123]

Vehicle: 2001 BMW 325ci Manual 250k miles
After having a rough idle and getting lean bank codes to be exact: Fuel Trim bank 1 Control limit, Fuel Trim bank 2 Control limit, Misfire on all cylinders and Fuel Trim Bank 1 & 2, Permissible range exceeded. I replaced my CCV, Intake boot (Lower and Upper) SAP vacuum line, and the non-return valve vacuum lines following the 50's kid video. Once I removed the Intake Manifold (IM), I found out the previous owner removed the vacuum canister and plugged the hole in the IM. Not knowing what to do I continued to replace everything double checking everything was plugged in. After I finished installing everything, the car would start then very rough idle and die within 2-3 secs. The codes I pulled are: System too lean Bank 1 & 2, All Cylinders Misfire with fuel cut off, and Multiple Misfires detected. I'm sure my vacuum lines are in the correct location and plugged in, could this be something like me accidently moving the throttle body flap? I'm worried I messed up. Also the air duct from the front of the engine to the airbox is missing don't know if that would be affecting my prior bad idle.

 

[reflex123]

The 325 didn't come with the exhaust flap as far as I know so that's missing from factory. Even so, I've done the same and it's perfectly fine. the missing air duct shouldn't be causing any major issues.

I'd go through the no start guide as above. Did you try running with the MAF unplugged?

Thanks for the info, I tried with MAF unplugged and it starts and idles around 900rpm but makes popping noises from the engine. What does this mean?

 

[reflex123]

Check your actual CCV, there is a little nipple that is used on M52TU engines (I believe). Sometimes replacement CCVs don't come with this blanked off (mine didn't anyway...) and will cause a big vacuum leak. I used a little rubber blanking cap and it fired right up after that.

EDIT: RealOEM.com - Online BMW Parts Catalog
I'm referring to #6 on this diagram.

I specifically remember transferring the plug from the old CCV to the new one. The 50’s kid also does it in his video which I was following.

 

[reflex123]

Will the engine run if you gas it a bit once started?

• It will not run. Check fuel pressure at the schrader valve on the fuel rail. It should be 50 PSI. You can watch the fuel pressure as you start the engine. If it will not hold 50 PSI then you have a failing fuel pump.
• It will run. This is indicative of a vacuum leak. Keep searching for it.

With the MAF unplugged, the mixture is very rich. This has allowed the engine to run. Again this is indicative of a vacuum leak as the rich mixture will compensate/mask a vacuum leak. The popping noises will be misfires due to an incorrect mixture.

Thanks for the information. While the MAF was still connected, the engine would start, rev to 1.5k RPM then shoot down and die. In my attempts to hold the pedal down the car still dies within 2 secs. What equipment would I need to test the fuel pressure? Thanks again!

 

[reflex123]

Lots of options for a fuel pressure test kit. Amazon, for example, has a ton. You can also rent it from places like Autozone for free (you pay for the kit, do your work, then return it for a full refund - see their website). Whatever you end up doing, you need to ensure you have the proper connector/adapter to the BMW schrader valve.

Just one example from Amazon, there are many.

JIFETOR Fuel Injector Pump Pressure Gauge Tester Kit, Automotive Gas Gasoline Fuel Oil Injection Test Tool Set 0-140PSI, with Schrader Adapters Universal for Testing Auto Car Truck Motorcycle

Buy JIFETOR Fuel Injector Pump Pressure Gauge Tester Kit, Automotive Gas Gasoline Fuel Oil Injection Test Tool Set 0-140PSI, with Schrader Adapters Universal for Testing Auto Car Truck Motorcycle at Amazon. Customer reviews and photos may be available to help you make the right purchase decision!

www.amazon.com

Thank You! Gratefully, Amazon will ship that kit tomorrow morning. I also plan on doing a smoke test to find any major leaks. I'll update once I've completed both tests. Thanks!

 

[reflex123]

Thank You! Gratefully, Amazon will ship that kit tomorrow morning. I also plan on doing a smoke test to find any major leaks. I'll update once I've completed both tests. Thanks!

Fuel Pressure reading about 47 psi with MAF in, with the MAF unplugged it’s about 49 psi.
I recorded the readings:
MAF Unplugged: MAF Unplugged
MAF plugged In: MAF Plugged In fuel pressure
I was sick this entire week couldn’t get the tests done. Darn flu! Waiting on some materials to do a smoke test tomorrow.

 

[reflex123]

MAF should have no influence on fuel pressure

With the MAF plugged in the car dies immediately, so wouldn’t the fuel pressure not have the proper couple of seconds to reach 50 psi? I have no clue just guessing.

 

[reflex123]

Alright I will thanks!

 

[reflex123]

Did the smoke test earlier today and found smoke coming from the bottom of the intake manifold. I'm going to take off the intake manifold, and recheck all the vacuum lines.

 

[reflex123]

You mentioned that you replaced the CCV so make sure you check that too. I find it helpful to use an inspection mirror to identify the source of the leak(s) from the smoke test before taking things apart. This way you can narrow down the areas to inspect. Keep in mind you may have multiple leaks. Good luck.

Yeah the CCV wasn't fully connected to the oil dipstick tube so it was leaking. Also the bottom my of intake boot wasn't fully connected either. However, once I took off the intake manifold I found out I lost 2 pieces that are inserted at the top right of where the gasket goes. I have one but no clue where the other one went. It looks like this:here what is it and would it cause my car not to start? Also, there is a lot of build up within the intake manifold, how should I clean it?

 

[reflex123]

A negative maintenance. 2 pieces dropped off and didn't even know.
Those pieces with holes for creating a whirl turbulent in the combustion as the air jet entering only one valve -- not equal symmetrical flow if both valves having the same air flow in. This helps to mix the fuel/air better. You have a large air leak with the missing pieces.

That makes sense, I double checked most things I guess those pieces got passed me.

 

[reflex123]

That makes sense, I double checked most things I guess those pieces got passed me.

Couldn't find the pieces on realoem or any retailer so I got some from the junk yard and almost done putting everything back in. I also believe the check valve was in the wrong direction, black being towards the intake boot side. I'm hoping I can get it started tomorrow! Thanks for the help everyone!

 

[reflex123]

This is what the check valve on the back of the intake manifold should look like. Ignore the numbers and the red lines. I'm simply reusing an old image that I used for another purpose......

View attachment 966410

Great! I had it on the right way. What problems would switching the direction cause?

 

[reflex123]

I had the same codes occasionally pop up for a while before the car eventually started misfiring one day, then would die a second after it started.
Not saying with 100% certainty that's what's causing your issues, but in my case it was a bad coil... If the coils and spark plugs are still original/overdue a replacement, that could actually be what's causing it instead.

I got a brand new valve cover, coils, and spark plugs thinking it would solve my problems. Bad idea! Fixed nothing.

 

[reflex123]

Short answer - your secondary air pump (SAP) would not be able to pump air into the exhaust manifold likely popping a code.

Long answer - the one-way valve (black/white), the solenoid that is connected to the one-way valve, and associated vacuum hoses are used to actuate the SAP injection control valve. It looks something like this and it's mounted to the exhaust manifold. (Note there are two different versions of this control valve so yours may or may not look like this picture.)

View attachment 966427

If you connect the black/white one-way valve the wrong way, this control valve would not get the necessary vacuum signal to open, therefore even if your SAP does run, it wouldn't be able to inject air into the exhaust manifold.

Thank You! I don’t remember how it was positioned before I took it off but it’s now in the correct orientation. I now need to put the throttle body, ICV, disa, and intake boot and I’m good.

 

[reflex123]

Thank You! I don’t remember how it was positioned before I took it off but it’s now in the correct orientation. I now need to put the throttle body, ICV, disa, and intake boot and I’m good.

I have great and bad news.I doubled checked all my work but it still wouldn't start, checked fuel pressure while cranking it was 30 PSI. I cranked it then revved to 2k rpm for 10-15 secs turned it off then turned it back on and now its about 45 psi and idles perfectly, is that good or bad(that i had to rev it)? Also, white smoke would come out of the exhaust when I start and rev the car, why would this be happening? Last thing, AC blower is now shot, I'd say 3/4 of the power lost. On full blast, barely anything come out and noise of the A/C blowing is very noticeable outside of the car, not sure if that was the way it was before, but im guessing a leak but no clue where to start. Thank you all for the help!

 

[reflex123]

Your fuel pressure should be 50 psi. From the info that you have provided, looks like you have a failing fuel pump.

As to the white smoke and AC blower, did you have these problems before you ripped apart the intake manifold? Are you losing coolant? Where are you located that it's warm enough for you to run the AC at full blast?

I did not have those problem prior to taking apart the IM. I think I’ve developed a leak but it seems very very small at the connection of a hose from the lower radiator, however, it felt like oil when I touched it. I worked on it in dark conditions so I’ll try to look more later today. I don’t need full blast however when I put it to 50% it’s nonexistent. Why would the AC lose power due to a coolant leak anyway?

 

[reflex123]

Your fuel pressure should be 50 psi. From the info that you have provided, looks like you have a failing fuel pump.

As to the white smoke and AC blower, did you have these problems before you ripped apart the intake manifold? Are you losing coolant? Where are you located that it's warm enough for you to run the AC at full blast?

When you say "nonexistent" are you talking about the fan blower or the AC compressor? Two different things.

The air blowing from the interior A/C is very very weak so I’m guessing the fan blower. I was referring to such when I said nonexistent, I’m not yet familiar with the A/C system, my apologies.

 

[reflex123]

So fan at 50% or temp at 50%. Do you get cold air with AC? Warm air with heat? I would deal with leak and fuel pump first.

Sorry for the confusion, temps are fine, I’m only taking about the power of the air coming through. At 50% I have to hover right over the vent to feel air. Fuel pump and possible leaks are my priority I just want to get y’all’s input on this. Thanks!

 

[reflex123]

What about floor and defrost settings?

Nothing changes, very low.