'99 2.8 Roadster not running right (details inside)

[JKuhn]

I didn't test the sensor, I tested the connector on the side of the engine.

I can also check the sensor resistance, but for that I need to know how many ohms between which wires.

Regarding the battery disconnect, that's what the BMW dealership mechanic recommended back when I replaced the torn intake boots.

[deni2s]

Regarding the battery disconnect, that's what the BMW dealership mechanic recommended back when I replaced the torn intake boots.

Change your mechanic.

[Tallyho322]

But then I'll need to find and buy the correct cable and adapter (and of course get the software). So it'll probably cost more than a normal code reader (and adapter).

Cable and adaptor were about $10 USD when I bought them this summer. Easily paid for themselves many times over as I worked on a few issues on my new to me 2000 M Roadster. And the software is free (doesn’t get any better than that...thanks to those who developed and shared it).

[JKuhn]

Change your mechanic.

This was not the mechanic I normally use. This was one of the mechanics at the BMW dealership, I asked if I should do anything else when I changed the intake pipes and he sugested that to clear any fuelling adaptations.

Tallyho322: Like I said, I'm in ZA. I need to find it locally, or pay insane import fees.

[BimmerBreaker]

Cant you find someone in the US to ship it to you and declare on customs forms either a gift or low value?

Even paying 100% import tax on a $10 set of cables doesn't seem that bad compared to the value it will provide you when diagnosing

[JKuhn]

I'll see if I can get it locally, to be honest I hate importing stuff (partially because I don't trust our postal service, any tracking stops when the item arrives in ZA, so it's impossible to know what's going on).

[Mr Bingley]

I'll see if I can get it locally, to be honest I hate importing stuff (partially because I don't trust our postal service, any tracking stops when the item arrives in ZA, so it's impossible to know what's going on).

Listen, if that's the only issue, I'll be happy to buy one and ship it to you in ZA as a gift--tell me exactly what you want and give me an address--no problem. It'll be worth it to me just to put an end to this endless circular speculative diagnosis.

[deni2s]

This was not the mechanic I normally use. This was one of the mechanics at the BMW dealership, I asked if I should do anything else when I changed the intake pipes and he sugested that to clear any fuelling adaptations.

That's a good suggestion. But clearing fuel adaptations is done with that cheap cable, not by disconnecting the ECU.

[JKuhn]

Listen, if that's the only issue, I'll be happy to buy one and ship it to you in ZA as a gift--tell me exactly what you want and give me an address--no problem. It'll be worth it to me just to put an end to this endless circular speculative diagnosis.

Thanks for the offer, but I'm not too comfortable accepting something like that. I'm sure you'd call it stubborn (and looking from your perspective I'd understand), but that's just how it is.

Anyway, looking back I certainly agree that I've been throwing money at it, but at least it gave me some insight into how these cars work so it's not entirely wasted. I'll look for a local cable (cheap option, but my current lack of experience with these things might count against it), and if I don't find it I'll get a proper BMW diagnostic test done (expensive option, but on the other hand they have way more experience than I do), and then do my due dilligence and get a cable. Once I know exactly what needs to be done I can save up and do everything in order of importance. But before I take the car to BMW I'll obviously first make sure that they're not just going to read codes. As I understand it's an extensive test though.

EDIT: Regarding importing stuff, I haven't had any issues so far, but I'm generally not comfortable doing it unless I have to. And by due dilligence I mean trying not to throw money away on the wrong ad.

[328 Power 04]

Listen, if that's the only issue, I'll be happy to buy one and ship it to you in ZA as a gift--tell me exactly what you want and give me an address--no problem. It'll be worth it to me just to put an end to this endless circular speculative diagnosis.

It just goes to show you how tightly knit and friendly this group of Z3-ers are. Great people here for sure.

[JKuhn]

I have no doubt about that.

[JKuhn]

It seems the sensor/diagnostics will have to wait. The Mazda just got a new thermostat, and the housing sprung a leak (I expected it, that thing is completely rotten). Unfortunately it's not easy to find a thermostat housing for the old E-series engines, everywhere I go I just find parts for the newer B-series (the facelift was sold here until '03 so everybody knows this car as the B3 323, even though it's an E5). So while the Mazda stands parked, the Z will have to be dailied.

Hopefully I can get a new one from Mazda in the new week, but if that fails I'll have to get it made by an engineering shop...

[JKuhn]

UPDATE

The MAF seems to have failed on a recent long distance trip. I'm currently running it without the MAF (I need to do long distance trips at the moment, and I don't trust the Mazda right now), but of course it's now even weaker on the bottom end (also misfires/backfires around 3.7k RPM at wide throttle). There is definitely a vacuum leak, but it's been there for a while (for some reason the mechanic didn't find it), so I suspect it's the MAF. Since I can't afford both sensors right now, which one will be the best? The cam sensor is around R2500 (should be able to buy it soon), while the MAF is around R8500 (at least a couple months of saving).

EDIT: I just phoned Hyundai and Kia, they asked R10240(!) and R11200(!!!) respectively for the MAF. I really didn't expect to pay less at BMW...

[325bob]

I tried to read everything!, haven't seen the oldest free diagnosis for your symptoms yet?, leave the rad cap loose after parking,and also during the next drive to see if coolant pressure is compromising any cylinders.And if so, I've seen stop leak products work occasionally,maybe 40%.

[JKuhn]

The blown gasket route has already been investigated. It's definitely throwing a code for the cam sensor and rear O2 sensors (I've since had minicats installed, and they said they'd clean the sensors if needed (and on that point, they said the sensors were probably just dirty)), and aparranlty it now also throws codes for the MAF and front O2 sensors. It kept going into limp mode, but that stopped when I disconnected the MAF.

Regarding the free diagnosis, I think it was in one of the old threads. It threw the following(DTC code, description):

41 Camshaft signal, inlet
154 Unknown
D7 Oxygen sensor behind catalysator bank 1 no signal
D8 Same, bank 2
CA Fuel trim bank 1 control limit
67 VANOS inlet camshaft, end postion not reached
CB Fuel trim bank 2 control limit
98 Oxygen sensor voltage behind catalysator bank 1

At the time, only the D7, D8 and 41 didn't clear. Also, I'll look at the first post again, maybe I can make it clearer there.

[BimmerBreaker]

UPDATE

The MAF seems to have failed on a recent long distance trip. I'm currently running it without the MAF (I need to do long distance trips at the moment, and I don't trust the Mazda right now), but of course it's now even weaker on the bottom end (also misfires/backfires around 3.7k RPM at wide throttle). There is definitely a vacuum leak, but it's been there for a while (for some reason the mechanic didn't find it), so I suspect it's the MAF. Since I can't afford both sensors right now, which one will be the best? The cam sensor is around R2500 (should be able to buy it soon), while the MAF is around R8500 (at least a couple months of saving).

EDIT: I just phoned Kia and Hyundai, they asked R10240(!) and R11200(!!!) respectively for the MAF. I really didn't expect to pay less at BMW...

Why are you calling Kia and Hyundai? They don't sell BMW MAF's

[JKuhn]

It is the same part though. (same Siemens number, saw a used MAF ad listing the different BMWs, Hyundai Sonata 4, and some Kias). Kia and Hyundai just have their own brand-specific part numbers.

EDIT: I see the ad I saw doesn't list the exact Siemens number I have, but look at this link:

http://forum.e46fanatics.com/showthread.php?t=822010

Page1, last post.

Mine is 5WK9605.

ANOTHER EDIT: Fixed the pricing in a previous post, just for the sake of accuracy (wrong price at the wrong brand).

[deni2s]

There is definitely a vacuum leak, but it's been there for a while (for some reason the mechanic didn't find it), so I suspect it's the MAF

If there is a vacuum leak then the cause of MAF, VANOS, O2 sensors or cam sensors errors might be just a vacuum leak. Fix that first.

[JKuhn]

Will do. I'll see when I can get it done, I just have a long distance trip to do this weekend (and I don't trust the Mazda right now).

[JKuhn]

Time to revive the thread.

As it is now, the car still has lean symptoms (also gets worse as I drive), and it runs better without the MAF (a shop replaced it with a knockoff, because the genuine ones are a bit out or reach right now). After seeing a club member's brother (he's a mechanic, and does private jobs in his spare time), he said I should get the fuel pressure checked, and that he suspects a weak pump (and also to get another MAF when I can). He did find and fix a small vacuum leak, but that didn't end the problems.

So what should the pressure be? I'm hesitant to just trust the info given by local mechanics. And if the pressure is too low, should I just replace the pump, or is there something else to check as well?

Keep in mind, I'd like to get it sorted out quickly as I need to travel far this week (signing for a new job and starting to move).

EDIT: Also, the massive leak I thought it had was not a leak. Aparrantly (this mechanic and two others said so) these engines do have a hissing noise at the manifold. And where the shops tend to just test vacuum, this mechanic tested by hosing the intake down and checking for misfires or noises of water being sucked in (obviously not massive amounts of water, just enough to make sure there weren't any leaks). This is also how he confirmed the existance of the small leak, and how he retested after plugging it (open vacuum port).

[328 Power 04]

3.5 bar rail pressure on load.
At idle, it may be just very slightly off, but should stay around there even with higher load and rpm.

- - - Updated - - -

Slight hissing can be normal (maybe), but also vacuum leaks can be at the crankcase ventilation system diaphragm, and you will never get an external symptom.

[JKuhn]

So it should be about 3.5 at idle? And how should it be rested with load? Does that mean I need to book a dyno session (I'd honestly prefer not to spend much more right now)?

[LannVouivre]

You can simulate a load by gently opening the throttle by hand until you reach the desired RPM.

[LannVouivre]

Please check the wires on your intake cam position sensor. It's reporting an issue with the signal being either improbable etc. and that the VANOS isn't able to actuate the full range of timing changes on the cam.

The possibilities may include: a wiring issue altering the values reported by the sensor before the DME receives and analyzes them; the sensor may be faulty and giving inaccurate signals; the VANOS may no longer be able to function properly through its full range, due to a failed seal or inadequate pressure from the solenoid. There are probably other possible causes.

[JKuhn]

I'll sort the cam sensor out later, for now I just need to get this issue fixed. The thing is, I still need to fix the Mazda (headlights, wipers, wheel bearings, clutch, and so the list goes on), and funds are limited. But I do know that there is sufficient power on the right terminals at the connector (DME side).

Anyway, I'll try to get this fuel issue (assuming that diagnosis was correct) sorted out before I do the long distance trip.