Moved from Texas to Salt Lake City + emissions questions

[Zeta]

Hi everyone,

It's been a long time since I've posted on here, but I just moved to Salt Lake City for grad school, and Pendleton dutifully got me up here. I was curious to see if there are any other e28's rolling around Salt Lake.

I'm trying to get Pendleton registered in Utah now and sadly he (barely) failed emissions. He was just a little high on HCs. Everything else was fine. Texas doesn't do emissions testing, so I'm new to the various tricks you can use to pass. I changed the spark plugs and oil today, so hopefully that will fix it, but I'm still kinda concerned. Even after changing the spark plugs, he still idles rough in park and neutral, though is perfectly smooth in gear. I read that this can be an ECU issue, but I don't want to sink money into that if I don't have to, since it seems the Super Eta ECUs are more expensive and harder to come by than the older ones. Are there other things that could be causing the problem that I could try to fix before buying an ECU? Or alternately (though probably not likely), is there anyone around SLC with a good Super Eta ECU that I could test out?

[RetiredDoc]

Does Utah have antique or vintage car registration that would exempt a 30 year old car?

If the e28 is your only car that probably won’t fly as it is a daily driver, though.

There are 15 super eta ecu’s part number 0261200154 on eBay today.

Are you still running the original charcoal canister?

[Mike W.]

If you just barely failed, I'd buy a bottle of the Guaranteed to Pass stuff, I've heard good things about it, put it in, drive the crap out of it to get the cat good and hot and bring it in for testing.

[tig]

Your car is exempt in Utah. Register it as an antique.

[Zeta]

Your car is exempt in Utah. Register it as an antique.

I don't know if that will fly. To quote the Utah DMV:

This plate identifies a vehicle at least 30 years old, is primarily a collector’s item, and used for participation in club activities, exhibitions, tours, parades, occasional transportation and similar uses, but is not used for general daily transportation. This plate may be personalized with up to 5 alphanumeric characters by submitting TC-817, Application for Personalized and Replacement License Plates with the required personalization fee. A vintage vehicle, as defined in Utah Code 41-21-1, qualifies for an exemption from safety and emission inspections.

It's my only car, so I'll have to be able to drive it every day.

[tig]

Your car is exempt in Utah. Register it as an antique.

I don't know if that will fly. To quote the Utah DMV:

This plate identifies a vehicle at least 30 years old, is primarily a collector’s item, and used for participation in club activities, exhibitions, tours, parades, occasional transportation and similar uses, but is not used for general daily transportation. This plate may be personalized with up to 5 alphanumeric characters by submitting TC-817, Application for Personalized and Replacement License Plates with the required personalization fee. A vintage vehicle, as defined in Utah Code 41-21-1, qualifies for an exemption from safety and emission inspections.

It's my only car, so I'll have to be able to drive it every day.

You'll be fine.

Also, note the emblem on the collector's plate is a sticker. You can remove it and replace it with anything you want. E.g.

[Zeta]

So you're saying that if a cop notices me driving the same stretch of road every day for my commute to campus, they won't pull me over for abusing the vintage plate rules? I don't know, seems kinda risky to me, as cool as getting the custom plate out of it would be.

[gadget73]

In NJ they won't allow a historic plate unless you have a regular plate in your name as well. Does Utah check that?

[tig]

So you're saying that if a cop notices me driving the same stretch of road every day for my commute to campus, they won't pull me over for abusing the vintage plate rules? I don't know, seems kinda risky to me, as cool as getting the custom plate out of it would be.

Your mileage may vary, but yes.

[Zeta]

Alright, well I think I'll try Mike W's suggestion first, but if that doesn't cut it i'll try registering it vintage.

[wkohler]

I would absolutely focus my efforts on making the car run properly. Not having to emissions test can let lingering issues fester until they affect drivability. Do you know how old your o2 sensor is? I’d change that (yeah it’s pricey since it’s the 4 wire) and your coolant temp sensor (blue Bosch connector on the thermostat housing - it’s super cheap insurance). I’d also have a look at the cap and rotor. You did plugs but several issues do come from those components and at a very least just put your eyes on them so see if there’s anything Abbey somebody.

[a]

Back in'04, my super eta,the Borman 6 flunked emissions by just a smidge. I replaced the dead O@ sensor I used a 3 wire Bosch for a 94 Ford. The 4th wire is only a drain to suppress noise . I cut the wires off the original O2 down low and but spliced the 2 together> I added a piece of bare wire and clamped that to the body of the new O2 with a hose clamp. These days you can get a Denso 3 wire for short money If you have avolt meter you can test the O2. You find out how on line better than i can describe it. Please post a follow up

Just replace the coolant temp sensor ,the 2 wire one. They can be tested, but its a PITA, just buy a new one. I'm a cheap SOB, If I say, just buy it...

Everything Kohler sez is true about the cap and rotor. If you have never had the cap off, now is the time. Look carefully where the rotor spins inside the cap if you see a thin dark line, thats carbon tracing and may be the source of a lumpy idle or a miss.

[Zeta]

I pulled the cap and rotor a couple days ago, and yeah, it’s all worn out. New ones are on their way from FCP Euro, along with a coolant temp sensor, just in case. Thanks for the advice, y’all.

[wkohler]

I bet if you change those parts, you will be pleasantly surprised.

[a]

Great pictures of cap + rotor. The bits of oily residue have carbon in them and are a sign that the cam seal is weeping. Next timing belt R+R, add it to the while you're in there list. Mean time, all you have to do is wipe the crap off the inside. Scrape the burnt contacts clean too. Save the old parts, after mkt parts are iffy. Use boot grease to save trauma to the plug wires. Keep us posted.

[Zeta]

Mean time, all you have to do is wipe the crap off the inside. Scrape the burnt contacts clean too. Save the old parts, after mkt parts are iffy.

I know it’s hard to tell from the picture, but I don’t think you realize how bad the cap contacts are. There isn’t just surface gunk on them: the metal is actually severely pitted, and practically hollowed out on a couple of them. I was concerned that if I scraped them clean, it might lead to them being missed entirely (I don’t know if that’s a reasonable worry, but considering he’s running well enough to get me around town, I don’t want to experiment with this cap and rotor until I have the new one in hand). Also FWIW, the new parts that I bought are Bremi, not some sketchy unbranded aftermarket ones, so they should be solid.

[SlickDizzy]

Lots of good advice already in this thread. Another tip: before you take it in for the test, make sure you do a fair amount of spirited driving with the engine under load and 3k+ RPM, then drive it in. This will get the catalyst nice and hot and increase the odds of passing a sniffer test.

Back when Wisconsin still had tailpipe testing circa ~2006 my Euro 528i failed the sniffer, despite having all of the common tune-up fixes recently completed. I waited out the mandatory period, then drove the living crap out of it for a few hours and brought it back in. It passed with flying colors.

These days they only test 1996-up with a plug-in OBD2 test, which is its own nightmare, but at least the classics are now exempt.

[Zeta]

Lots of good advice already in this thread. Another tip: before you take it in for the test, make sure you do a fair amount of spirited driving with the engine under load and 3k+ RPM, then drive it in. This will get the catalyst nice and hot and increase the odds of passing a sniffer test.

Ahahaha, 3k+ RPM spirited driving in an unmodified Super Eta, ah that's comedy gold right there.

Jokes aside though, cap and rotor came in last night and I replaced them this morning. One thing I noticed that I hadn't before is that while the old cap was Bremi, the old rotor is Bosch, so there's a chance that the rotor is original and has never been replaced, unless whoever changed them last bought different brands.

After changing them out, I drove Pendleton up Millcreek Canyon to get warmed up before the test.
He passed no problem! Overall, he's idling better, though it's still kinda rough in park or neutral, while in gear it's totally smooth.

I also realized today that the coolant temp sensor I bought from FCP Euro was mislabeled, and is actually the thermo-time switch: https://www.fcpeuro.com/products/bmw-co ... 2621710512 (it's brown with one prong, the coolant temp sensor is blue with two prongs)

Should have bought this one: https://www.fcpeuro.com/products/bmw-vo ... 0280130026

I checked the resistance of the sensor as described in the Bentley manual though, and it was within the correct range, so I don't think it needs to be replaced, but I'll probably add one to my next order since it isn't expensive, just for peace of mind.

Even though he passed and can be registered now, I'm wanting to fix this problem for real now that I've started down this path, so I could use some suggestions on what to test or replace next. ECU? Spark plug wires? O2 sensor? Something else?

[wkohler]

No thermotime switch since there's no cold start valve. That's the temp sender for the gauge.

Glad you passed.

I'd do the o2 sensor. Unlikely you need an ECU, I like to replace the coolant temp sensors becuase they're cheap and can ruin your day. It's also highly unlikely you'll ever have to replace BMW spark plug wires. Also checking out the crank sensor is never a bad idea as well if you don't know the history on it and if you replace it, don't get a cheap one.

[Zeta]

No thermotime switch since there's no cold start valve. That's the temp sender for the gauge.

Glad you passed.

I'd do the o2 sensor. Unlikely you need an ECU, I like to replace the coolant temp sensors becuase they're cheap and can ruin your day. It's also highly unlikely you'll ever have to replace BMW spark plug wires. Also checking out the crank sensor is never a bad idea as well if you don't know the history on it and if you replace it, don't get a cheap one.

Thanks, I'm kind of confused about what you mean by the temp sender though... I tried to figure out what I was looking at from the Bentley manual and it was a little confusing. It doesn't mention a temp sender at all, and it looked like they were saying that part was the thermo-time switch. Not doubting you, I'm just trying to understand what all of these parts do.

By crank sensor, do you mean this? https://www.fcpeuro.com/products/bmw-cr ... 2141720856

[wkohler]

Forgive me if I've used terms interchangeably, just trying to be most efficient with the typing.

Motronic 1.0 cars (pre-3/87, though there are some 2/87 Super Etas) have three sensors. A temperature sender with a single spade connector (for the gauge), a blue two pin Bosch connector, for the ECU - called the Coolant Temperature Sensor or CTS or Fuel Injection Temperature Sensor in many parts houses. They also had a brown two-pin Bosch connector with a thick base that is a temperature sensor that is called the thermo time switch. This is used to power the cold-start injector below a certain coolant temperature for a certain amount of time.

Motronic 1.1 (Super Etas) have two sensors. Gauge sensor and the blue coolant temperature sensor (CTS). There is no thermo time switch because there is no cold-start injector.

Yes, that is the crank sensor.

Also, just saw your photos of the rotor and the Bosch rotor was made in 1995, so it is not the original one.

[Mike W.]

You made me look. The rotor was made in '96, no real difference, still not original but old enough to drink.

[Zeta]

Ah, I totally missed the 96 stamped on there. Next paycheck I'll buy a new O2 sensor, as well as the blue coolant temp sensor, and replace both of those along with the brown one that I already have. Thanks!

[Zeta]

Pendleton is officially registered in Utah now! I likely won’t do further repairs until the spring though. I’m gonna garage him over the winter as soon as the road salt rears its ugly head, and I’ll need to focus my energy and parts budget on my new winter beater:

[wkohler]

Congrats!