M62TUB44 Swap or not???

[Billyj]

Ews has multiple paths of intervention, it can withhold power from the starter and I believe it can keep the coils for firing as well. I had a 10 year no start 325i a few months back, took me like a week to get the ews figured out lol. Just wish I remembered some of it lmao

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Glad you got it figured out!

[KVF]

Ok, so now that it's running I've noticed a somewhat low and lumpy idle and the acceleration feels like something is holding it back. I don't know how to explain it, but it feels as though the engine can't effectively take in air and/or get rid of it. It initially jumps as I nail the accelerator, but it's as if anything beyond half throttle simply grows slowly. No matter when I go full throttle it feels like it wants to accelerate harder, but instead it just gains speed at the same pace.

I do understand that it may take time for the DME to adjust, but I also used the B30 air intake box and MAF, which is smaller than the B40/B44. Could this actually cause a lumpy idle and stifled acceleration??

Beyond that, I'm a bit nervous that my Cats starting to fail. I know there's a ton of other options to check, but it just clearly feels as if there's something restricted at intake and/or exhaust.

Any insight is greatly appreciated.

Thanks!

----------Edit---------

The more I read up on this the more I think it's perhaps cats AND the MAF. I have the B40 MAF already and the air box I can use it with will arrive next week. Does anyone think it's not safe to drive the car in the meanwhile??


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[Billyj]

Does the power suddenly 'come on' or surge at high way speeds when accelerating at partial throttle? If so I'd suspect tps
Does the maf have a different part number between m60b30-b40 and m62-m60? If so the maf is culprit.

Is your fuel pressure good?
Have you checked for vacuum leak?

[KVF]

There's no surging. The idle is low and it's not smooth. You can feel the car shake/rock in tempo with the idle. It idles more like a cam'd 70's muscle car.

The MAF is certainly at least part of the issue. It is a different part # and the B30 unit I'm using is also visible smaller in diameter. I already have the larger air box on order to use with the larger MAF. At this point I'm just wondering if I'll do any damage by running it this way, or am I merely just limiting performance.

I'll check fuel and vacuum once I verify that it essentially safe to continue using this MAF.

Thanks for the reply and insight!

Karl


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[AHenry014]

You certainly need to be using the b40 maf with that setup. Not sure i would drive it. The MAF is responsible for telling the DME how much air is incoming, which then tells it how much fuel to dump, timing to use, etc. I would wait for the b40 maf.

[KVF]

I don't see why it would "hurt" anything unless I was really pushing it and ended up running it really lean, BUT I agree it's best not to try my luck. I won't be running the car again until Wednesday when the air box arrives.

Thanks yet again!


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[AHenry014]

Try to put the b40 maf on that you have and see if it smooths everything out. Unless you put a temporary cone filter on there, i wouldnt drive it too extensively.

[KVF]

Read my mind. I have a buddy with a K&N that will likely fit. I plan to test it at idle. If it smooths out, I may consider driving it a bit.

Generally speaking, I despise those messy and ugly K&N filters.


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[AHenry014]

Ive had great luck with K&N's and so have friends of mine. Supposedly they are over oiled from the factory. I tend to buy them used then refresh them. Never had an issue. I use the dry media filters now, i.e. AFE. I do agree though, the stock airbox looks the cleanest.

If youve got any sort of filter on it, drive it man!!

[KVF]

She's up and running with the correct MAF & air box!! The idle is still low and lumpy, but the car pulls well and doesn't make any odd noises. I'm going to put some miles on to see if it smooths out and raises idle before I start messing with coils, injectors, and the like.

Thanks again for all the help!




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[Billyj]

Bump for results? Just curious how old is your fuel filter ?

[KVF]

The idle smoothed out a bit, but it's still low and I'm pretty certain there's a misfire going on because it's perfectly rhythmic. I don't have any knocks or ticks, so I'm thinking for best to worse case scenario... Coil has gone bad, injector is clogged, or I have an extremely low compression cylinder.

I've committed to putting 200 miles on it just to see if it works itself out (at 155), as the motor was sitting for a year prior. If it hasn't worked out, I'll start pulling coils one by one to find the misfire and go from there.

Thanks for all the help guys! I will certainly report back and as always I'm open to suggestions.

FYI- I don't suspect the fuel filter, but that's a good maintenance item to change anyway, so I'll change it next week.


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[KVF]

Update... The engine still idles very low after 200+ miles, but pretty much feels good otherwise. I pulled each coil while it was running and it consistently ran rougher.

Spraying around the intake and vacuum lines didn't reveal any leaks... However, when I unplugged the ICV it showed no change in idle speed or smoothness. I'm going to grab a new Bosch unit...


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[Billyj]

You can check to see if the icv is working, just pull the boot off or w.e and watch to see if it clicks open/shut. Or apply voltage and see if it responds smoothly. If it's dirty it can get jammed

[KVF]

I cleaned it while everything was apart, so I know it's not jammed, but I didn't specifically put an ohmmeter on it or apply voltage. I suppose I should do that before buying a new one.

Also, the B30 & B40 ICV's are the same correct? I haven't seen anything suggesting that they are different.


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[AHenry014]

They are the same.

[KVF]

Thanks I'll put a meter on it tonight...

On another note, did anyone who performed this swap have problems with drive belt tensioners? The left side upper timing chain case does not have a place to mount the 3rd bolt from tensioner. I'm nervous about apply too much force to the other two bolts, as the housing is aluminum. Yet, the belt currently bounces and chatters a bit. Anyone else run into this or know a way around it?


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[KVF]

ICV has been replaced with a known good unit for giggles but the lumpy low idle remains... This thing sounds like a cam'd 69 dodge 440 6 pack and only idles around 500-600 rpm. I guess I'll move on to possible fuel delivery issues


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[Billyj]

Clogged injector possibly, just s thought. I forget, but did you ever check your spark plugs ?

My gut would lean towards a small vacuum leak of some sort though

[moroza]

~600rpm is normal idle.

My serp belt tensioner (the main one, not the AC) bolts only to the lower timing cover.

[KVF]

Good to hear that 600 is normal, but it rarely stays there. It's typically exactly at 500 or just below the white line.

Billyj I do suspect a clogged injector and I'm kicking myself for not having them tested and cleaned while they sat for a year+. I "may" pull them (read on). And yes, the plugs are fresh, although I haven't pulled them for a read on how engine is running...

I shouldn't complain too much as the car pulls and runs well. It merely has an issue at idle.

Thanks for the belt tensioner info Moroza! I was going crazy with it last night trying to get it tensioned in a manner wherein it wouldn't squeal every time I turned the wheel at idle. It finally dawned on me that there's an issue with my ps pump. It has a firm spot in its rotation and I'm now wondering if that's actually my lumpy idle. oO


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[KVF]

New development... I let the car idle for 15 seconds or more it settles at about 400-450 rpm and the check engine light comes on. The second I touch the gas the light goes out. Would a stomp test give me a code even though the light is not on constantly?


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[AHenry014]

yes i believe so. Hows the voltage at idle?

[KVF]

Great thanks!

I don't have an actual gauge in car, but all of the electronics work as intended and I don't get any noticeable surges or power drops when I turn on/off the lights or AC unit.

I picked up a ps pump and will get it on the car on Sunday or Monday before doing a stomp test.

Thanks again guys! What a wonderfully helpful community.


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[AHenry014]

Theres a way to get the voltage readout on the OBC.
http://www.m5board.com/vbulletin/alp...functions.html