Installed Miller MAF and all hell's broken loose (Video)

[HotWaterMusic]

Alright so I adjusted my valves to .009" and put everything back together. Started it up...and the ticking sound is still there. The idle is still terrible, wants to die every 5-6 seconds, and after 20 seconds of running, the car smelled as if it could not be running any richer. I am at a loss now. I wasn't expecting a valve job to cure my problems, but I thought it would at least making the valve ticking sound go away...guess not! Any outside the box ideas as to what's going on here?

[shocka]

The injectors are loud on these engines, are you sure its not mostly that you're hearing?

[ahab]

How would you rate the engine's idle stability before you did the MAF conversion? These engines are really pretty simple. You've ruled out the CTS and any vacuum leaks, although leaks usually causes high idle. The next step would be to clean the ICV and throttle body. It's unlikely that simply installing the MAF would cause these issues to manifest themselves but it could be that the AFM setup was more forgiving for whatever reason. The CSV is another common cause for richness. Carefully clamp off the fuel hose from the bottom of the fuel rail to the CSV and see if that changes anything. I use needle nose Vise-Grips with a piece of fuel hose slid over the jaws to protect the CSV line from the sharp teeth but you can also purchase a proper. As mentioned, it's not unreasonable to have to adjust the throttle stop after installing the MAF. Generally it's not a good idea to do if you haven't ruled out other causes of poor running, but it's not completely out of the question. Others have had to. None of this will explain the no-start from the other night however.

I would start by removing the ICV and TB and cleaning them. Check the throttle plate for proper gap, if it's low then you obviously need to open it up. Do the screwdriver test mentioned in your other thread to determine if your hearing valves or injectors (although that would only confirm that your valves need to be adjusted again...). Did you follow Miller's troubleshooting guide for the MAF itself? It might be worth pulling the ECU connector and checking for continuity across the MAF connector pins, confirming that your solder job is correct.

As a test, wedge your feeler gauge in between the throttle stop and the linkage to simulate a few thousandths adjustment and see what that does. If the motor runs much better you may want to find a semi permanent "wedge" to take it out for a test run before actually changing the factory setting.

[HotWaterMusic]

The ticking sound is definitely the fuel injectors. Screwdriver test confirmed that. Also, the "coolant" idiot light comes on now, but it's been off and on the whole time I've owned the car--before I changed the CTS and after--so I always thought it was just the light acting up, not an actual coolant issue. So, assuming the coolant light is actually on for a reason now, does that shed any light on my idle and running issue? I cleaned the ICV probably 3 months ago. I think removing the throttle body on this car is out of my league unless there's a good thread here going over the process. And just so I am sure, the TPS is the device mounted to the throttle body with the little button on top that lifts as soon as you give the car gas, right? How exactly do I test that that is working properly?

[mooseheadm5]

The coolant light is just for coolant level and had nothing to do with running.

[shocka]

I typed "TPS tests" in the search bar, worked well.

Do you have a Bentley manual, theyre invaluable for these cars.

[ahab]

When you adjusted the valves you did 80% of the work required to remove the throttle body. Remove all that same stuff, except for the valve cover, and after you get the intake bellows off the only things left are the throttle cables and the 4 nuts for the throttle body itself. The cables are quick release and don't require you to do any adjusting to them, just squeeze the white plastic thing (photo shows it in black instead) and press it through the throttle actuator. Do it for accelerator and cruise cables, then use a 1/4" drive ratchet with a 10mm socket and a 6" extension to remove the TB. Don"t drop the nuts. Disconnect the TPS connector and pull the vacuum hose off the nipple under the TB and you're all set. Here's a photo of the things you have to squeeze to get the cables off. Yours will be white, squeeze the two ears on the bottom and press them through. they'll be oriented differently but the concept is the same. Don't undo any nuts but the 4 around the TB.

[HotWaterMusic]

Thanks a ton, Ahab. Exactly what I needed to know. I'll do that tonight.

[LandCruzer94]

Thanks a ton, Ahab. Exactly what I needed to know. I'll do that tonight.

Don't forget to clean the vacuum line nipple at the bottom of the TB, a small paper clip works great.

[Duke]

Why doesn’t anyone use the SS MAF kit?

http://www.splitsec.com/products/mafkits/MAFkits2.htm

I had one on my M535i, worked well.

[TodB]

The Miller MAF kits appear to be about half price to start and installation is pretty straightfoward, there are only a couple of two wires to jump. with the latest gen. Those who buy the Miller kit rather than the SS can use the $ saved and buy APPL

The issues being discussed in this thread I don't believe have to do with the MAF so much as adjusting the idle correctly.

[HotWaterMusic]

http://www.youtube.com/watch?v=cBzVLRAcB1Q

I did some research and read over on Pelican that my O2 sensor could be the issue with my low/dying idle. It said to unplug the orange connector on the passenger side firewall and see if that effects the car's idle in any way. I posted a video of what I believe is the connector they're speaking off. Can someone take a look real quick and tell me if thats the O2 connector, and if so, while the car is idling I just disconnect it and observe how the engine runs? No change would mean the O2 sensor is shot or malfunctioning, correct? I'm doing the throttle body cleaning today, I didn't have time last night unfortunately.

[1st 5er]

A different connector from the E28, but it appears to be in the right place.
Following the wires down the exhaust to the O2 sensor is easy enough to do though.

Best of luck in bringing this baby home.

[HotWaterMusic]

Ok, so here's a little follow up. I removed the throttle body and cleaned it, including the vacuum nipple on the bottom. I replaced the hose leading from the vacuum nipple to the dual hose plug it goes into.
Here's where I am sure did something wrong though: I adjusted the throttle body so that the plate is completely horizontal at full pull, which it wasn't when I took it off. Obviously adjusting it to open wider made it not close completely when at rest. But I'm talking not closed by .0X of an inch. So in the name of trial and error I buttoned it all back up and started the car. The idle fluctuated a little, but ultimately settled at about 900RPM. And it's suppose to idle at 750RPM, right? So I'm off there a little. Also, the TPS button doesn't get clicked by the plastic arm now. So it doesnt engage. I'm off by a couple MM of it being clicked down. How big of an issue is that?
But the thing is, the car doesn't die now when it comes down from revving it. And I drove it around the block with no issue. It feels absolutely no different with the Miller MAF than it did with the stock AFM, but that's a whole different rant. So in one sense, it's fixed. But I'm sure it's either: A.) A temporary fix or B.) Causing more problems to come later
Any thoughts or advice?

[mooseheadm5]

If the TPS does not close the idle switch, it will not idle properly. If it does not close the full throttle switch at full throttle, it will not go to the full throttle map. Adjust your TPS.

[HotWaterMusic]

Aaah, the car runs now, and idles at 900. If I start messing with the TPS I'm only gonna screw something up. Besides I read that on the EH auto trans cars the TPS is used to tell the trans when to shift and kick down, which it's doing fine. So I'm gonna leave well enough alone.

[LandCruzer94]

Aaah, the car runs now, and idles at 900. If I start messing with the TPS I'm only gonna screw something up. Besides I read that on the EH auto trans cars the TPS is used to tell the trans when to shift and kick down, which it's doing fine. So I'm gonna leave well enough alone.

It's really not that hard to adjust.

[M5BB]

This sounds like a classic ECU intermittent problem.

By getting in there and replacing the chip etc the board may have been tweaked and now you have an intermittent problem.

Search for ECU repair, solder or something like that.

[Rich Euro M5]

Aaah, the car runs now, and idles at 900. If I start messing with the TPS I'm only gonna screw something up. Besides I read that on the EH auto trans cars the TPS is used to tell the trans when to shift and kick down, which it's doing fine. So I'm gonna leave well enough alone.

In it's present state, your car is screwed up.

Based on your previous symptoms you have several things going on with the adjustment of the Throttle Body (TB) and TPS. You may also have a problem with the Idle Control Valve (ICV) pr possibly the driver transistors and circuit traces in the ECU..

When the throttle body is adjusted correctly, the base idle with the ICV fully closed should be 750 RPM. When in this state, the TPS should also be closed, this is important as it tells the ECU the engine is at idle. Ideally the ICV should only open to compensate for additional loads such as placing an automatic transmission into gear, or turning on the A/C or other engine loads that might impact the idle speed. The TPS should not be assumed good based on hearing it click. You need to confirm it's closing using a multimeter or test lamp.

Your assumption regarding the EH transmission kickdown is incorrect as well. The potentiometer driven by the TB doesn't control the kickdown. Kickdown is initiated by a switch located on the drivers side floor under the accelerator pedal.

[ahab]

In it's present state, your car is screwed up... ...possibly the driver transistors and circuit traces in the ECU..

Truth. FWIW, I ran this ECU in my car for 35k with no issues. While it's not impossible for the solder joints to go at a given time, I think that's probably too coincidental to be a real factor in this circumstance.

I adjusted the throttle body so that the plate is completely horizontal at full pull, which it wasn't when I took it off. Obviously adjusting it to open wider made it not close completely when at rest. But I'm talking not closed by .0X of an inch. So in the name of trial and error I buttoned it all back up and started the car. The idle fluctuated a little, but ultimately settled at about 900RPM. And it's suppose to idle at 750RPM, right? So I'm off there a little. Also, the TPS button doesn't get clicked by the plastic arm now. So it doesnt engage. I'm off by a couple MM of it being clicked down. How big of an issue is that?

Adjusting the throttle cable stop so that the plate is horizontal at full open should not affect the plate closing all the way at rest. These are two independent adjustments. The cable sets full open, the throttle stop sets full closed. If this did happen in your case then I'm reasonably certain that your throttle stop was too low to begin with.

I'm not familiar with the auto TPS so I don't know what you mean when you say "clicked by the plastic arm", but you need to adjust the TPS so that the switch clicks when the throttle closes all the way. This is important for a few reasons, emissions, fuel economy, trailing throttle, etc. As Rich has pointed out, you can't do this by the click alone, you need to check the pins for resistance with a meter. I would suggest getting out a meter and resetting your TPS, this will have no impact on the throttle adjustment and your 900rpm will not be affected. UNLESS, by telling the ECU that the throttle is truly closed, the resulting mixture is insufficient (for lack of a better word). Personally, I would adjust the TPS per the Bentley, and if the idle is poor then adjust the throttle stop until you get the RPM you want (750). As I suggested before, try a temporary wedge in the throttle stop with your feeler gauge and see if this improves your low idle. If the TPS is correctly set and the idle is now good, set the throttle stop to the new location and call it a day. This is a far better situation the running the car with the TPS out of spec. You mentioned O2 sensor, if you don't know the mileage of yours, and don't want to test it, simply buy another and replace it. It's a key component of a good idle/tune and worth the $50-$100.