Author Topic: While doing the mess under the intake -- what the heck part is this? (Read 5676 times)

iwanttobecold · « **on:** March 17, 2018, 05:30:45 AM »

https://imgur.com/gallery/2hSlt

Currently doing the mess under the intake. This part does not have a BMW part number on it or any other mfg part number. It was looped between the two t-connectors underneath the intake. It has a I and a II marked on it.

My throttle body heater was gone when I bought the car, and the engine isn�t the original, so I�m assuming this is some sort of water plumbing they added to close off the line going to the throttle body heater.

Do I need to put this back in the system? If so, where?

1998ccc · « **Reply #1 on:** March 17, 2018, 09:34:50 AM »

I've never seen one of those on a M42. If you are not going to run the throttle body heater, just buy a new BMW hose that comes out of the top of the plastic water pipe. You can twist it around to attach the other end to the nipple on the head. That completes the cooling part.

Valve cover goes to throttle body nipple and ICV goes to intake boot. That's it.

iwanttobecold · « **Reply #2 on:** March 18, 2018, 09:06:19 AM »

I got it all done and put back together, but alas, it is still having the acceleration/bogging down issue from previous.

Successfully got her back up and running and now... Still a little rough on idle, but once I get it in gear, I can tell there's definitely a better fuel response. However, I'm still bogging down under acceleration, mostly in low RPMs.

In the past 3 months I have replaced: spark plugs, air intake tube, fuel rail, fuel pump, fuel filter, fuel hoses, vacuum hoses, coolant hoses, tested/replaced faulty ignition coil; and cleaned out ICV, MAF, and throttle body using MAF sensor cleaner.

I don't really think this could be transmission-related, but at this point, I have to ask: could it? I don't know what else intake related I could possibly replace besides the throttle cable... The main issue is the car shaking (I had assumed misfire and so did a BMW tech), bogging down, as in low RPM range for that gear, accelerating on an incline or heavily.

Ex: Driving in 3rd gear, try to punch it and accelerate. If I'm on flat ground, it will possibly accelerate without bogging down. On any incline, however, it will bog down every single time. Also, if I was in the 1500 RPM range in 3rd gear and tried to accelerate, it would also do this until I give it the right amount of fuel (letting off) or just accelerating until it 'catches up'.

1998ccc · « **Reply #3 on:** March 18, 2018, 07:51:02 PM »

Boging is normally a lean condition. Look at anything that allows too little fuel or too much air. Dirty injectors / clogged fuel filter / low pressure / volume. Check fuel pressure with and without vacuum hose connected. Verify DME coolant temp sensor (blue) with DVOM. Look for cracks in the boot from AFM to TB. Intake gaskets leak?

Have a local buddy with know good AFM you could try?

DO you have a newer M42 with knock control?

Main relay original. They can go bad.

Wouldn't hurt to clean engine grounds and the positive junction block to make sure you are getting proper voltage.

Good luck.

iwanttobecold · « **Reply #4 on:** March 19, 2018, 05:56:14 AM »

The injectors were cleaned, so I know it's not that.

I can check the fuel filter again, but I replaced that just a few months ago. Also just replaced the intake boot and intake manifold gaskets, so they're good. I will check fuel pressure, DME coolant temp sensor.

I don't have anyone around at the moment to try out a different AFM. However, a few weeks ago I left the AFM unplugged and fired it up, it ran but extremely rough (idling at 2500RPM with the CEL on). I would assume if this part was bad, then the CEL would come on when it's plugged in as well.

Thank you for all your help, and I will see if any of your suggestions work!

monty23psk · « **Reply #5 on:** March 19, 2018, 07:54:37 PM »

Have you looked at the O2 sensor? I don't believe it was mentioned here. Also, how about timing? I had a rough idle and never went away until I fixed the timing. I replaced everything you did. ECU could be an issue as well.

Author Topic: While doing the mess under the intake -- what the heck part is this? (Read 5676 times)

iwanttobecold

While doing the mess under the intake -- what the heck part is this?

1998ccc

Re: While doing the mess under the intake -- what the heck part is this?

iwanttobecold

Re: While doing the mess under the intake -- what the heck part is this?

1998ccc

Re: While doing the mess under the intake -- what the heck part is this?

iwanttobecold

Re: While doing the mess under the intake -- what the heck part is this?

monty23psk

Re: While doing the mess under the intake -- what the heck part is this?