Let put an end to this weird idle/gas mileage, w/ video.

[Kozworth]

I swapped pumps.. still whining. I am debating replacing the fuel filter again to see if that fix the whine.

As for idle, still fluctuating.. I really dont want to break into the valve cover and recheck the valves again. I set it under cold (i believe its .025) so If the valves are at that just give it a less drag and I should be good?

As for idle, its a little lower around 550, still getting the sputter. And sometimes (like when i went to park my car today) it went up to 1k, stayed there for 5 secs then dropped back down.

[paperplane94]

You mentioned the FPR vacuum hose had a scent of fuel and to me, that is a red flag.
There should be air and only air in that hose.

I say change the FPR and see what happens, they are cheap enough, cheaper than fuel pumps.
Got mine from blunttech.com brand new. for around $20


Reasoning:
When you clamped the return line (from the FPR) the excess fuel pressure probably did cause a High amperage draw on the fuel pump blowing the fuse, but it might have also caused fuel to enter the intake through the leaky FPR Diaphragm. My car idled just like yours when the FPR went south. One distinguishing factor was when you blipped the throttle, the car wanted to die from a stop, even while in Drive/Park.

[paperplane94]

One more thing. It would also account for the bad gas mileage.

[Kozworth]

Yea I asked my teacher he said it was common unless you see gas then its an issue

I was thinking the same thing that if its vacuum there should not be gas

Im not getting black smoke I actually was getting a cloudier white from the exhaust after the pump switched but it was a foggy day so not sure if it was just an illusion

I read to suck on the vacuum line to the fpr and if you could creat vacuum its golden which I think it did maintain some but it smelled of gas

Ill probably try to orddr a new fpr tonight anyways cuz I need an alternator tensioner too

[Kozworth]

Replaced fuel filter and fuel reg still have this idle

[Quinthirty]

Any updates? The smell of gas on mine is driving me crazy. The bad fuel consumption is too. I also noticed that under the throttle body, its moist, and I'm thinking that there's a leak.

Will have to test for vacuum leaks first, and look at all the fuel lines 2nd. Hope its solves the problem. Is it also possible that the charcoal canister needs to be replaced?

[Kozworth]

It could be, smoke test the evap system too.

Mine was good, then i smelled some the otherday. The fuel feed line to the rail clamp loosened, it was so minor but smelled so strong. Tightened that up, and it has been better.

Im going to remove the bav chip, because ive read a lot that the pcm cannot adapt to the chip so it can run pretty rich.

Also, my header to downpipe bolts have a couple missing. Gaskets are beat too. Im wondering if thats leaning out the air to the o2sensor, making the car think its running lean and start to add more fuel.

[Quinthirty]

Didn't know that the chip can really do that as the ECU should compensate. I'm changing the hoses today and checking all the fuel lines. My charcoal canister may have to be replaced too. I think it has 100k km on it already...Anyone with a better solution / modification?

[Kozworth]

Im still not totally sure on the chip, trying to find the page that I read the otherday on how it scews with ecm fuel mapping.

Its wierd, I never smell gas yet I am getting 20mpg even with mostly highway driving and not going too crazy on the gas pedal.. Most guys here say a solid 25 is what is the normal.

[Quinthirty]

When the car starts cold, it idles like its a cammed muscle car. Originally when I had it, it would even out to a normal idle when it reached operating temp.

Now, it idles like its cammed, whethor its cold or warm. When its warm, its not as bad but still does it.

Idle is around 600-650 ish, when it used to be about 750 solid when it idled fine warmed up. I have not adjusted the idle at all.

Gas mileage is still very poor. In the bentley, it said a rich running car would idle erractically or something along those lines.

My guess: Since the car idles the worst when its cold, its in open loop. Its running off the inputs, and not the o2 sensor. Since the car still idles iffy when its at operating temp, I am wondering if it is stuck in closed loop. This would cause excessive rich conditions, and my poor fuel mileage all the time.

Ive been sick and cannot smell correctly (damn cold) but Ive also been smelling a gas scent. Ive looked all around the tank (replaced it a couple months back) and the lines seem alright, and no leaks underneith my car ever from what I have noticed. I did notice a smell under the hood, and I know the p/o replaced lines to the rail. I am just wondering if this has any relation to being in open loop.

I have exactly the same problem now. I replaced everything to tune it well, but it is still idling a bit rough. Also discovered that ECU was for a 320i, and replaced it with the right one. I will look at the purge valve tomorrow as I also smell gas evaporating especially when its parked overnight. No leaks underneath though. All smell is coming from the engine.

I noticed another thing though, and it might be unrelated. Once, I tried to run her with lesser gas (1/4 and less), and experienced hard starting. It was cranking, but it did not fire. It took 5 clicks to start the engine. When I filled her up, everything seemed fine but after a week, I noticed that when I park for awhile 15min to an hour and try to start her (very hot weather now...high 90s to 100s), she won't start, or will start to a sputter, as if flooded (I don't step on the accelerator). Vapor lock? Several times, it died, as it hovered at 500RPM and struggled to increase in RPM. If you flick the gas pedal, it dies. The thing that works is to crank it, don't step on gas, and let it start. While it sputters, wait for the RPM sputter to increase in RPM, then, flick the gas. Once it runs though, its fine. While sitting in traffic, I also experienced slightly higher RPMs at 800-1000RPM.

Appreciate some advice. Thanks!

[Kozworth]

I know I've read somewhere when you hit about 1/8 a tank many people notice the car not running nearly as well. I drive my car until the gas light is on, and do not really notice much.

My cars the opposite, it seems the warmer out it is the better it idles (like about 700, no little sputters.. Its completely still sometimes I think the car shut off). But for the most part its about 95% perfect. Drives and everything is great, its just im a perfectionist and try to take my 24 year old bmw to idle like a 2012 car.

Just some areas ive read about/replaced that really helped my idle:
-adjust valves. I did mine the first time w/ the correct prodecure, but holding the eccentric, feeler gauge and tightening all by yourself can be bound for some slips. I did it, and checked it again later on and the valves were way out. I recommend having a friend tighten or help out, and do both intake/exhaust valves when they arent open, and then double check them after a few turns.
-Intake leaks. Purge valve is a huge one. Tend to rot and fall off. Also, replaced fpr line w/ the "smallest" vacuum hose from an auto place and hose clamps. Sprayed w/ carb cleaner, and they still leaked, just get the regular oem replacement and forget the headaches. Check all brakebooster lines, iac line, main intake bellow for cracks.
-If those are in order, you could check the tps. Basic jist is to test the continuity. Disconnect the battery, hook up an ohm meter and see if the position of the butterfly matches the correct resistance values. One is for idling, so possibly if that is out of wack that could screw things up.
-Lastly id check fuel pressure, but finding a fp tester kit was annoying (have to splice a t right before the fuel rail, most kits just have a regular screw on fitting but e30s do not have this fitting). Id do this because it takes a bit more time, I have a post requesting a e30 capable fuel pressure kit, they are online.

From what i read, I would not try to even mess with the AFM. Just swap them and see if it helps, or clean out the connector. I wouldnt open it at all, you can read up on it. I am just getting a cel at idle at times, but since my WOT is out of limits on my tps I cannot flash the code.. Not a big deal since the car drives great as is. Hope this helps

[Quinthirty]

That helps. I'd test it and see. I'm afraid though that the AFM has been tampered with especially when they changed the ECU.