Messages

1

Engine + Driveline / What could it be? (Bogging down under acceleration, incline)

« on: March 19, 2018, 05:58:14 AM »

Hello, all...

Just did the mess under the intake. 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, it's 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'.

I can list more parts that I've replaced as I remember them, but it's important I figure this out before I move cross country this summer with it!

2

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

« 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!

3

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

« 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'.

4

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

« 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?

5

General Topics / Re: The mess under the intake

« on: March 13, 2018, 05:41:59 PM »

Surprised that people are still posting on this 11 year old thread...

I've ordered all my parts and I will be doing the MUTI this weekend, along with replacing the fuel injector wiring harness (which had been chewed by some rodent). I've also got a new intake boot to throw on it, and I hope that all this will solve my idle/misfiring on acceleration mess.