AustrianVespaGuy

Yeah as bad as it looks, this is totally fixable. As Mike indicated, you want to tear out all the 'new' stuff and leave the original stuff alone. Fortunately, it seems like it's pretty easy to tell the two apart! Once you have all that 'aftermarket' crap ripped out, things will get MUCH easier, and we'll quickly be able to trace any faults left with the original wiring/systems. Granted that Megajolt is probably running your ignition at the moment, so we might need to keep that, but I still say the first step is to get all that crappy wiring out and then rewire it PROPERLY if you going keep it.

I guess just pull you jets and do a quick blast with carb cleaner to make sure none are plugged up, but honestly those symptoms to me point much more strongly to an ignition issue than a fuel one. You SURE that Pertronix is 100% in good shape?

*Sigh* Ok, @zinz wins!

Be slightly more specific, which portion(s) of the exhaust to do you want to replace and what kind (stock/street/race) of parts are you after?

While we're here necroing this 2006 thread. . . anyone know what happened to @Zenon? The guy still has his site up with a treasure trove how-tos on his early EFI stuff which is awesome. Hope he's still around and enjoying his 2002!

While that Inka is the obvious choice of those listed, BaT somehow omitted what otherwise *would* have been very strong contender: A 914 looks daaaamn nice in orange!

Well. . . necroing this cause I just used one of these in part of the beer line chiller system in my kegerator and couldn't help thinking that, in a pinch, it *might* just about fit in an 02 heater box, and it's even LESS then $30! https://www.amazon.com/gp/product/B000C39C9A

No no no! I gotcha covered with a $50 solution instead! Do first sort out the electricals and make sure you have proper power/ground going to the fan. But even if you do and the fan itself is just dead, then just do what I did: snip out the old fan from the engine side, throw it in the trash, and get a 5.2" Spal, slip it in there, zip tie it in place, and wire it up. Literally good as new for like $40 + shipping + 30 minutes of small-hand work, removal of the heater box not necessary! Details here: https://www.bmw2002faq.com/forums/topic/73949-heater-box-fan-replacement-cheap-and-easy/?page=2&tab=comments#comment-1446529 And yes obviously pics or it didn't happen:

Don't bother getting rid of it, instead just repurpose it into something useful instead! Great real estate for either small digital readouts or LED bargraphs (mine are AFR and battery voltage)!

This. . . doesn't actually matter that much. Ideal phasing for sequential injection allows you to run a little leaner at cruise since you're not 'leaving much fuel behind' in the track or on the back of the valve, but that's about it. Batch fired engines run just fine, and as soon as you add some throttle, the time the injector is open becomes longer than the intake valve is open anyway. At this point it's all the same game of loading up intake tract with the right amount of fuel, and then waiting for the valve to open up and suck it all in. Point being spark timing is critical while spark amount (dwell) isn't so much, but for fuel it's the opposite and amount is WAY more important than the timing!

Ok, so here's my thoughts after looking at the datalog (attaching screenshot): - I don't really see any 'stumble' in the RPMs, however I do see what look like a few 'spikes' or 'surges' such as the one right where the cursor is. RPM seems to jump from 2300 to 2450 in half a second and then comes right back down. Think this is what you're feeling? I sorta doubt the engine is actually doing that, and think this is more likely an artifact of crank signal noise or reading of a 'phantom' tooth, but the ECU doesn't seem to be flagging any tooth errors either, thought the 'Trigger Tooth Count' varies wildy, though I don't really know what that parameter means. Does the S14 use a 60-2 VR trigger wheel? - Sensors all look good, so I'm pretty sure 5v ref/sensors/etc. are NOT your cause. - Acceleration enrichment is turned off, right? While the TPS position itself looks pretty good, the derivative/TPS rate is a bit more wild, probably from a bit of noise. Make sure it's grounded at the ECU, and when you go to put turn accel enrichment back on, make sure its activation threshold is ABOVE this level of noise. - AFR looks REALLY good, only going a bit lean right when you roll on the throttle, which is exactly what one would expect with no accel enrichment, so I also don't suspect any problems in you VE table/fueling in general. - That said these injectors might be a tad on the large side, only 1.6ms and 2.5% duty cycle is kinda borderline on the low side, but would need to see what they're at during idle, and again not something that would cause your stumbling issue. - Timing looks fine too, pretty stable in the 25-30 deg BTCD zone. I know the plugs look good and you still had the issue with the stock distributor, but I don't want to rule out ignition just yet as the symptom still sounds like an ignition-related one. What coils are you using and are they logic-driven or is there a high current driver for them somewhere in the system or ECU?

Can you post/share any of the logs? Would love to help more but really need to see the data in order to try to find something useful!

Whatever your Haltech can take a log of. Being able to see crank/cam signals, commanded ignition timing, pulsewidths, and AFR are probably the most useful things to look at to start. But if there's more that's OK too; usually you can filter down what to display pretty easily, so better too much data than too little!

Step 1: Check plugs Step 2: Run in wasted-spark COP mode instead of sequential COP. Step 3: Post a datalog.

Err, I don't think this is really necessary, as the original spade terminals are the same size as the spades on all the modern flasher relays. So just use a jeweler's screwdriver to release the locking tabs, pull out the female spades from the socket, bend the locking tabs back out, and then just stick them back in the new 'correct' spots to mate with your new flasher. At least that's what I did, so the new flasher just now plugs into the factory socket, and then just need to run the new/extra ground wire.

Well, not really, because this quick/free test would at least tell us for SURE that the fault IS with the alternator itself, and not somewhere else in the car's electrical system. Would suck to replace a perfectly good alternator and then still have the same problem, wouldn't it? I'm already 95% sure the alternator is the fault, but that final 5% confidence comes at an awfully cheap price. I too do prefer upgraded/internally regulated alternators when doing a replacement though!

It's almost for sure the diodes, as the non-alternator side of the light is fed by 12v switched by the ignition. So if it were the ignition switch side, you'd very likely have something 'else' that's obviously not turning off correctly as well. Test is pretty simple. You'll want to disconnect the big red wire going from the battery to the alternator, but still leave the battery connected to the rest of the cars electrical system. If the light then goes off, as I expect it will, then you'll know that your errant 12v is coming from the battery and *through* the alternator, instead of being 'stopped' by the alternator diodes. Though I suggest disconnecting the battery negative before you go to undo the positive wire from the alternator, and then only replace it once you have that lose wire safely isolated and impossible for it to touch any part of the engine/chassis before reconnecting the negative side. Safety first!

Wow, good job FAQers, this is about the sanest discussion I've ever seen on this matter, thank you! My personal opinion echoes that of many already shared here, i.e. you can consider the environmental cost of producing the 02 both a 'sunk' cost and also one that's already fully depreciated. On a new Tesla though, you need to account for the full thing. This makes the comparison *just* the operating cost of the 02 vs. the production PLUS operating cost of the Tesla. Since the operating cost of the Tesla is lower, these two curves will eventually cross, but my suspicion is that it's a good number of years off in the future, probably something like 20, and I SERIOUSLY doubt that most EV drivers will still be driving those same cars 20 years down the road. And as soon as you trade it in for a newer one, then you need to lump in that initial production cost again! All boils down to less-consuming = lower footprint. On the other hand, the shift from IC to electric drive for newly manufactured transportation I think does make a lot of sense, but I don't like the current trajectory very much as it still focuses on every individual commuting alone in their own personal vehicle. I always say it's REALLY easy to spot people who ACTUALLY care about environmental impact: they're the ones to go to work on bikes, busses, trains, and on foot.

Here's my take on this topic: - Center console gauges are too low to easily take in with a quick sweep; really gotta take your eyes off the road to look down there, so I don't prefer them. - Most important gauge IMO is oil pressure. Key to engine health, the dash idiot light isn't really adequate, and it even indirectly gives you an idea of oil temperature. (I.e. I know my engine is warmed up once the pressure at idle drops below 30 psi.) I mounted mine in that otherwise fairly useless little spot on the very end of the dashboard to the left of the instrument cluster, so I can easily see it when I do a sweeping glance of all my gauges. - While less critical, I also *like* to keep an eye on my AFR and voltage, but for this instead of big gauges I just use little LED bargraphs built into the otherwise useless seat belt warning pod (AFR on the left and voltage on the right):

I've kicked this idea around for a LONG time, (starting 15 years ago when I investigated using an inverter and a high efficiency AC window unit) and it can sorta be made to work but there's one real unfortunate kicker: The amount of current an electric compressor draws at startup is just horrendously huge. The load once the compressor is up and going is manageable with a stout 12v automotive system, but getting it through those first few cycles is the trick. Think if it just like starting your engine. Doesn't take much at all to just keep it idling, but to overcome all that inertia and compression you need the super-torque form the starter motor PLUS a huge gear reduction to crank the thing over first. This is why EVs use both higher voltage (usually 48v) supply AND fancy soft-start compressors to run their A/C compressors. I suspect Classic Retrofit compressor probably also has some sort of a soft-start feature to keep things in check, but it still needs one heck of an alternator output to feed it. I'm sure the 911 guys love it since there's literally nowhere to mount a crank driven compressor in those cars, but as much as I *want* to try it (for science!), that's an awful lot of $$$ for an experiment. And I have a hard time stomaching spending 911 level money on the 02, that's why I drive an 02 INSTEAD of a 911 after all!

If you decide to go ITBs instead of carbs, hit up either me or @jimk and we'll help you along with the EFI stuff. He's a Haltech guy and I'm Megasquirt, but we're both here to help whichever direction you decide to jump!

While I don't think I've seen/heard anything recently with regards to N20 swaps, I HAVE seen lots of recent stuff crop up regarding successful K20/24 swaps. . .

This too is a very good point. One of the BEST things about driving a 2002 around is the fact that with some driving competence, you can really have fun on pretty much every drive. I mean, don't be a dangerous menace on the street, but for example when I drive my M5 around town, I barely ever hit peak torque, I NEVER hit peak power, and I basically never hear any complaints from the tires. The 2002 on the other hand, can check each of those boxes between every light! That, and the indescribable satisfaction of perfectly matching each and every heel'n'toe downshift makes the car extremely rewarding for those who *really* drive it. Cue obligatory link to David Davis Jr. 'Hymnals' article: https://www.caranddriver.com/features/a15126456/1968-bmw-2002-review/

Yep, sorry! E30 tach is driven from a 12v square wave sent from the ECU, while the 2002 tach is driven straight from the flyback voltage spike coming of the negative side of the coil every time the coil fires. You could hook the 2002 tach to the negative side of your M20 coil of course, but then with 6 pulses vs. 4 it would always read 50% too high. You might be able to get some sort of tach adapter, but honestly I think the easiest route is to just swap out the tach for one meant for 6 cylinders.

This all depends on *how* you are setting up the new ignition control with the UMC. Since it has 2x ignition outputs (though I'm not sure whether they're high current or just logic drivers), you have the option of going wasted spark and not using the distributor at all. The other option would be to keep the distributor, but with its ONLY job of sending the spark to the correct cylinder. In this case, with the UMC controlling the timing of the coil, you want the distributor locked down so that it doesn't change timing at all by itself. The 'finger' on the rotor is wide enough to cover the full range of timing that you need, but you want the computer doing all the control, and not complicating things with computer timing PLUS distributor timing. Make sense?