My 1988 e30 325ix - Garage'd

[bradnic]

nice work and thanks again for sharing these great pics.

Currently running a modded OEM airbox with M30 AFM and mustang injectors on my m20, which I will stroke soon. Heading towards a MAF conversion myself as well, and definitely planning on keeping the stock airbox in some way. your pain my gain lol.

hang in there.

[jeenyus]

This weekend has been slightly frustrating. Miller MAF is good, but I have a lot to say about the product and their customer service (aka just Brody running the company over there).

Alright, I went two different routes with this process and the second one was more successful, but I'll show steps to both.

So since the MAF unit housing, in no way, was ever intended for the stock airbox, I had to get creative. I first created a template to get the dimension right. The template was plastic, so easy to manipulate with my dremel.

Here is the template placed on the airbox.


I then marked what needed to be cut and started tearing my dremel into this box. These airboxes are incredibly strong. The zinc plating on the inside is nearly indestructible.

Here is the box mid cutting.


My original idea was I could push the MAF housing into the airbox far enough where it would fit the rubber intake elbows dimensions still.

Here is how it looked when I burned through all my dremel cutting discs.


I held it in the box using a coupler and a strap.


This present a few issues though and didn't seal properly or to my liking.

So, I thought through it and decided the adapter I bought on eBay could probably work better. I took everything apart stuffed the adapter plate in from the inside of the airbox and already started liking the results more.

Here is the better idea from the inside of the airbox.


This worked better cause I was able to bolt down the adapter where before it wasn't very efficient. I was then able to completely seal it with some black RTV.

Then I needed to take off about 2" on the MAF housing to make it short enough to fit a coupler to join the airbox and MAF housing.

This was much more successful and I will replace the blue (all I had at the time) with something black in the future.




Here is how much I cut off the housing... by hand.


The car though, still has some issues driving. At first I couldn't believe how nice it was, but that was short lived.

The car has been giving me grief still with this install so I'm not sure what I've done wrong. The DIY instructions are fairly obscure in some sections. But I was able to successfully make it through the troubleshooting and determine the MAF is hooked up correctly voltage wise.

I have been getting error 1215 though and also there is one portion of the DIY I'm still trying to figure out if i did it wrong or now.


I understood this as cutting #12 completely and T'ing that into #37, but now I'm wondering if it should be a bridge. [emoji848]

[jeenyus]

nice work.. looking forward to hearing about your results.

Thanks man!

Would it be easier to simply put a cone filter on and fabricate a little airbox for it than try to make the stock airbox work? Bummer that you would have to ditch that little airbox adapter plate though.

Interested to see what you come up with! I'll be embarking down this path soon too. Working toward getting megasquirt up and running...

It would be easier, certainly. I just like the idea of the airbox so much. It's designed to be in there, it's been proven to work, it's less obvious too, which i think makes for a more sophisticated look (look at me using that word...)

I'm sure I can figure something out. :)

[zwill23]

Would it be easier to simply put a cone filter on and fabricate a little airbox for it than try to make the stock airbox work? Bummer that you would have to ditch that little airbox adapter plate though.

Interested to see what you come up with! I'll be embarking down this path soon too. Working toward getting megasquirt up and running...

[bradnic]

nice work.. looking forward to hearing about your results.

[jeenyus]

I've been taking the bus for the last two weeks and also a car dance between my wife and I for those two weeks, BUT I finally got my Miller MAF conversion yesterday.

It came in a nice little package. I installed the chip last night, soldered wire 12 to wire 37 and plugged in the MAF. Car started right up without hesitation.

I haven't had a chance to drive it though because the adapter I created for the MAF didn't work out so I'll have to spend some time figuring out that this weekend.

Below are a few pics of the endeavor.

I got this adapter from eBay. This is after I cut the bottom a few millimeters to get it to fit.


It looked out of place so I painted it.


Then put it on the stock air box (AFM is hella heavy!)


Got the parts


Then found out it didn't fit at all...


I'm sure I'll be able to figure something out this weekend. 🤞

[jeenyus]

This morning I was unable to start my car. Did the pump test, got error code 1215. That is an error code for the "MAF Sensor". I unplugged the AFM and was able to start the car no problem. Looks like I need a new AFM or it's time to convert to a MAF.

[jeenyus]

Over the weekend I had the chance to pull the intake manifold out of my car. I had planned on it being finished on Saturday, but the mail service had other plans.



That being said, I'd say it was still productive. I was able to clean my intake, replace the inline and return fuel line on my fuel rail, which would have been a pain any other time. I got to test my c101 and injector harness and make sure it didn't have any issues in continuity. I was able to install my blower motor as well. Tomorrow I'll get the chance to finish reinstalling the manifold.


Blower motor in!


Everything removed


Valves all look good.

I'm ready to be done and see how it drives.

[jeenyus]

where is that last pic taken from? Is that under the intake manifold?

it's under the intake manifold. the wires you can see are the connections for the crank sensor and the circle plug where you reset your service gauge. Left would be the toward the front of the car. These are the bolts under the front of the intake manifold closer to the thermostat housing.

[audiquattrot]

where is that last pic taken from? Is that under the intake manifold?

[jeenyus]

A few updates.

Nothing serious.

I changed my airbox filter from the paper filter to a much better K&N panel filter.

Old vs New


I also think I found my air leak. I stared inspecting the intake manifold, which I had figured wouldn't be the issue since the head was rebuilt at some point, and sure enough... when I got the brake cleaner in there just right I could change the idle with a slight spray.
You can also see the buildup around the mounting points.


So I ordered two new o rings from ECS for the oil return tube and then ordered some wave washers and nylon lock nuts from McMaster-Carr (great website).

Next weekend looks like I'll replace the gasket.

[jeenyus]

You have to do a smoke test to find vacuum leaks. They can hide in the craziest spots.

Yea it's gotta happen. I think I'm gonna try the whole electric bike pump and soapy water first, then smoke. It's such a consistent 1k idle too I know it's gonna be something I kick myself for not thinking about.

[ThatM20Guy]

You have to do a smoke test to find vacuum leaks. They can hide in the craziest spots.

I can definitely attest to this. I was trying to track down a leak for about 2 months...got it smoke tested and found out that the back of the o-ring for the oil return tube was pinched and not sealing. Would have never found that had it not been smoked.

[Kershaw]

You have to do a smoke test to find vacuum leaks. They can hide in the craziest spots.

[audiquattrot]

I'm also dealing w a 1k idle. I've eliminated any vac leaks, icv, ecu...also adjusted the throttle stop properly. Have a new throttle position sensor waiting to go in when it warms up with hopes that fixes it.