91 318is 1500rpm IDLE

[monty23psk]

And you said the MAF is brand new? Wanted to make sure the flap is not getting stuck open but  its more about the throttle. Did you do the bypass of heater plate coolant hoses? do you have the hoses ran the correct way? I find this odd with a brand new MAF and ICV. From what I have dealt with, a vacuum leak while make the idle rough or low, never higher.

[Crummy Cream]

Yes brand new MAF like brand new same with the ICV both are Brand spanking new lol so is the tps I  Doubt a vacuum leak would cause this as u said this seems like a mad could cause this problem and I don't have access to my multimeter anymore so I cant even check the voltage  >:

[Crummy Cream]

is it possible that its because they're not oem their aftermarket because the oem ones were out of my budget

[Crummy Cream]

also, i did not bypass the heater plate i'm almost pos it hooked up correctly too this is so frustrating I'm just afraid that because since it idles high that the motor won't be able to handle constant stress during running.

[monty23psk]

OEM is the best, not sure about aftermarket quality. Do you still have previous MAF and ICV? If so, you can try one at a time to see if it fixes the issue.  I also see you have that extra pigtail on the MAF connector from the video. Have you tried bypassing it? I forgot the reason for it. My car didnt come with it.

[Crummy Cream]

Ill test this after work thanks man for all the help

[DesktopDave]

That sounds like a really high idle. Typically it's due to a vac leak. Does your shop have a smoke machine? If they find a leak it'll be the best money you ever spent, these cars have huge problems with vac leaks.

You re-connected all the vac hoses, right? The plumbing is all going to the right places? Is the blind plug back in the throttle boot? I'm not criticizing, just suggesting a way to eliminate possibilities. I'm only saying this because I've caused a new problem for like every three problems I've fixed. I've left brake parts loose, forgotten to plug the block drain, etc..

It's been so long since I've done this job, I can't recall where the hoses go. IIRC the ICV hose goes from the throttle boot to the manifold, the PCV hose goes to the lower throttle body, the FPR goes to the tee that also goes to the fuel tank vent valve. The brake booster hose fits in there somewhere too. I'll take a look at mine tomorrow & let you know.

Anyhow...other things I'd check:
Has anyone messed around with the TB plates? If they're stuck open at all, even a bit, your idle will be very high. There are two plates to check (and a linkage), they both have to close tightly so that the ICV can do its job.
Check the AFM for smooth door movement.
I don't think the later type M42 TPS is adjustable. The earlier ones had slotted holes so you could rotate them slightly.
Does the car idle high all the time, or only when it's warmed up? If it's only iding high when warm, What's the DME temp sensor resistance?

[Crummy Cream]

the idle is high on startup only I almost pos i hooked everything back up ill have to take a look and I asked someone in service if we can perform a smoke test and they told me to bring it in after work this weekend to take a look so itll be free to test the vacuum line system thank god I hope I find my issue soon. I'll also take a look to see if the TB is slightly open do you have a way of testing the AFM Door to see if it will open?

[DesktopDave]

Idle should be pretty high on start up, mine runs at about 1500 for a minute or so depending on temp. Yours seems even higher than that, I agree that something is wrong.

The ECU/DME controls that setting by using the ICV and running a very rich mix. The DME detects temp with two sensors. Coolant temp (CLT) is in the cylinder head, air temp (IAT) is built into the AFM. They're really easy to test, just hook up a multi-meter in ohms (resistance) mode. A cold sensor will have a very high reading, like 9000 ohms (9 KOhms). As the temp climbs, the resistance falls. A hot sensor should only read out a few hundred ohms. Dean & I posted a pretty good thread about that here:
http://www.m42club.com/forum/index.php?topic=18012.msg123483#msg123483

I'd recommend testing it all to eliminate problems and save yourself some cash. I use a multi-meter more often than any other tool! I bought a good one on Amazon for like $40, it's paid for itself many times over. Don't replace stuff willy-nilly, test it all. You run the risk of swapping out a good part for an incorrect aftermarket part. Here's a good post I wrote a while back about the sensors and how they should be tested:
http://www.m42club.com/forum/index.php?topic=17926.msg124060#msg124060

Be aware that there are two very similar parts on the head. The CLT sensor runs to the DME, it's critically important. The coolant temp sender runs to the gauge cluster. It's relatively unimportant. The engine temp sensor has a brown case and two pins, usually mounted further forward. The gauge temp sender has a white case and just a single pin. If you swapped a few plugs around the wrong way when you did the hose delete, that'd cause some troubles. I've done it myself...the oil pressure sender, temp sender and CLT sensor all use the same plug, and the wires are long enough to put them together wrong. When I did the hose delete years ago, I mixed them up. I ended up with an oil warning light and the temp gauge never responded. Just like the crank & cam sensors...or the coil plugs for that matter...the same wiring connector plugs in the same locations make it pretty easy to mix them up.

I'll have to check my documentation to see which sensors the DME uses during the warm-up open-loop mode. I know that it ignores the O2 and many other sensors. A/C and O2 will also bump up the idle, but I don't think that happens until after the car warms up, when the DME switches to closed-loop mode.

Sorry about the novel I just wrote, LOL. I hope it's helpful.

[Crummy Cream]

No thanks for the novel when i get off work im gonna send some pics of my vacuum lines and tb setup and im gonna borrow a multimeter from one of my techs

[Crummy Cream]

Okay guys still havnt solved the problem, but now i need a new fuel tank

[monty23psk]

why?

[Crummy Cream]

My fuel tank has a hole in it but i just put some epoxy on it to patch it for now diy stuff but anyway o think i found my idle problem and its my throttle body i think one of the POS F'd with it because the new tps does not fit in perfectly right away i have to turn it about 25 degrees for it to fit in meaning the sensor thinks the throttle is being pulled about 1/4 of an inch even though its not correct me if im wrong because im going insane trying to find the reason behing this

[Crummy Cream]

I think that this silver part that is sticking out here is misaligned


Here is a Video showing what I mean please don't pay attention to the music in the back
https://drive.google.com/open?id=16Fz5q4kmKBv5_I9N-0YawAOxIItZQdR6


And here is another video of the idle in here I put the car in gear and slightly let off clutch to show RPMs drop, but then they go back to 2k
https://drive.google.com/open?id=1jUl3yX1pEWb-iPtEYIRCMK5yd-l1o0c3

Shortly after doing this the car started rapidly changing From 1500 to 2k rpms however I wasnt able to catch this on video

[DesktopDave]

I think your part is good, the TB is supposed to put a little bit of pre-load on the TPS. The TPS isn't an on-off switch like in older BMWs, it's a variable-rate resistor. The DME (ECU) calibrates the throttle position automatically. So if the TB plates aren't adjusted to be fully closed at idle you're going to have some trouble.

I'll pull out a spare TB/TPS if I get a chance and double-check for you. I'm pretty sure the Bentley manual has a testing sequence for that part too, IIRC it has three pins, one is the 5VDC power in, one is the signal out, and the last one is a floating ground directly to the DME (ECU).