24v Swap: Help me pass California BAR!

[phreshkid]

Alright ladies and gentlemen, I'm coming to you for help on this one. I am nearly there in terms of having a BAR'd swap and wanted your opinion and expertise as to what I need to do to turn this frustrating corner.

In 2011, I went to the CA Referee with a stock obd1 m52 running a red label 413 ecu. Nothing was done to the engine except a lower temp thermostat I believe. I was running obd2 exhaust manifolds, obd1 e36 m3 midpipe to stromung catback exhaust. Nothing crazy. Here is the smog attempt for that day.



After this test, I didn't try to have the car BAR tested for a while. In between the last test and the upcoming SMOG test that you will see in a second, the following modifications were made:
-S50 Cams
-TRM M52/S50 Cams Tune
-Timing was corrected (It was off by a few degrees according to Chris Castro)
-Exhaust was modified after the manifolds but before the CATs for corrected exhaust flow
-New Radiator
-I can't recall what else I have done since then to modify the engine to increase power output.
-All maintenance was taken care of (spark plugs, fuel filter, oil, oil filter, air filter, etc)

Here are the results for this SMOG test that happens roughly 2 weeks ago:



My emissions scores got SIGNIFICANTLY WORSE. What happened? I immediately called Chris Castro and promptly stopped by for a new set of replacements CATS, new fuel filter, and new throttle boot breather hose. This all happened about a week ago FYI.

I go in today for another crack at the Referee Station and here are the results:



As you can see, I passed the 25mph test on all accounts but the 15 mph test is still bad. NO readings dropped about 300ppm from 2 weeks ago's SMOG attempt but it is still three times the accepted amount, putting me in the Gross Polluter category. The engine runs fine honestly but there is clearly something wrong for me to fail.

I understand NO is typically produced when the engine combustion chambers exceed 2500 degrees F and a culprit of this would be running too lean (more air is entering the combustion chamber than gas, causing an imbalanced combustion, leading to high NO). HC is also too high but not by much.

I heavily appreciate any input on what could be the cause of this and the fix to this problem as well.


Also, the engine is being tested as a 1995 m3.


Thank you for reading and thank you again for any response that may lead me to the fixing of my little problem. I am so close!

[phreshkid]

After a bit of research, I realized how important it is to keep your CATs as hot as possible. For these last two tests, Car sat for almost an hour before the 15/25mph tests were run. This leads me to believe that if given the chance to drive hard for a good 20-30 minutes immediately before the test, I might have a much better chance at meeting the SMOG requirements. Regardless, before I go in next time, I will have changed my oil, cleaned out my MAF, cleaner air filter, check spark plugs, seafoam the engine, and run it hard for a good 200-300 miles to allow the new cat to pick up a few miles.

The new CATs had roughly 80 miles on them before today's test.

[iwantspeed]

keep us updated\
good luck with your projects.

[MR 325]

One big recommendation I have is putting in a stock temperature thermostat. There is no reason to run a lower temp thermostat and it's going to make your engine and emissions less efficient.

[Bimmerman325i]

how new is the o2 sensor?

[dnguyen1963]

Have you eliminated all vacuum leaks via smoke test?

[jlevie]

High HC and high NOx can be the result of partial misfires, which in turn can be the result of intake leaks. When caused by intake leaks the problem will usually be worse at lower engine speeds. Such a condition would be consistent with your test results. Have a smoke test run to see if intake leaks are present.

[GDA]

Check for vacuum and/or intake leaks like Jim said and in addition you should also look for weak/failed coils and bad plug to coil stingers. If you see any yellowing on the ceramic of the plug then that it a sign that you have issues on that coil and/or boot

[phreshkid]

One big recommendation I have is putting in a stock temperature thermostat. There is no reason to run a lower temp thermostat and it's going to make your engine and emissions less efficient.

I'm not entirely sure why I changed to a lower temperature thermostat to begin with but this was about 2 years ago now. I am hoping to resolve this issue without pulling out the radiator/swapping the thermostat for a stock s50 thermostat. This is definitely on my "Possible and Probable Issues" list.

how new is the o2 sensor?

I installed a brand new O2 sensor about a month ago.

Have you eliminated all vacuum leaks via smoke test?

This is my best guess as well. I do know that the "Goose neck-shaped vacuum tube thing that plugs into the intake manifold from underneath is loose due to me breaking the clip that secures it into the intake manifold itself. Based on yours and Jlevie's comments, this is my my next move.

High HC and high NOx can be the result of partial misfires, which in turn can be the result of intake leaks. When caused by intake leaks the problem will usually be worse at lower engine speeds. Such a condition would be consistent with your test results. Have a smoke test run to see if intake leaks are present.

I will learn and perform a smoke test to identify any leaks associated to the vacuum system and the intake manifold. This actually makes good sense.

Check for vacuum and/or intake leaks like Jim said and in addition you should also look for weak/failed coils and bad plug to coil stingers. If you see any yellowing on the ceramic of the plug then that it a sign that you have issues on that coil and/or boot

I never thought of coils as being a weak point but then again, this is why I came to you gentlemen for help. I will learn and perform this test as well.

[maneeno325e]

in order to keep your cats up to temp, while your waiting at the station ive heard of people just revving the car to 3k rpm while waiting in line in order to keep the temps up. not sure if its frowned upon or not but if a catalytic converter is cold, its not going to do its job no matter how well your engine is running. i say retry it with a nice hot cat before you waste money on parts.

[TimKninja]

I dont know if this helps, but i failed my emmisions test twice on my stock M20 with 260k. I quickly went to the nearest auto parts store and bought that "Guaranteed to pass" stuff. Added it to half a tank, drove the cart arounbd at 5k RPM , brought it back and it passed with FLYING colors, better then a 2012 Kia Soul,

Get the cats NICE and hot.

[jaywood]

My smog guy knows e30's pretty well and actually warmed up the cats for me at the station. He told me it was a waste of gas trying to get it hot before coming to the station...all of the air flow and everything else cools it off too much. So he held it at 3k rpm for about 3 minutes and it passed easily.

[Deathtoll]

Interesting Read. I hope I can get my car bar'd some day.

[phreshkid]

01-24-12 Update:

So my swapped car passed and is going to a good home. This has been in the works for months but before she goes, I wanted to give a little insight of what happened the last two or so months.

So about a month and a half ago, I had Michelangelo's BMW Shop in Lakeforest, CA perform the vacuum test and sure enough, I have three major leaks. One was at the throttle body boot, one was under the intake, and the third was at the brake booster hose. I bought all new parts and had them replaced. We went to two different smog shops and had the sniffer test performed twice. The numbers were where we wanted them to be so in my confidence, I set up another test with the referee station.

It turns out I was wrong.

The referee guys let the car idle for about 4 minutes before they put it on the dyno and perform their tests. In an ideal world with an ideal car, this is adequate time to allow the car to reach operating temperature and have the cats warmed up and ready to perform.

They ran the car through the 15/25 mph test and without fail, I failed yet again.
Here are the results of that test. Take in mind that all vacuum leaks had been taken care of and the car was running better than ever.



As you can see, the numbers did drop considerably from the last set of tests, but the catalytic converters still weren't doing their jobs! I had a hunch that I had purchased faulty cats from Castro's shop. In all reality, I was probably the 1% who had the misfortune of purchasing faulty cats straight from the factory. Not a big deal. I will have to return these faulty units to Castro's. Chris, expect a friendly call from me soon.

I took the car back to Michelangelo's where Richard immediately got to work. Through his network of reputable guys, they were able to diagnose that the cats weren't adequately cleaning up the exhaust gases. I shelled out another $600 for a pair of high-quality Walker cats and replaced the spark plugs to a non-iridium bosch unit (this was at the advise of Chris Castro- Thanks man!) and set up another appointment at my local referee station (Golden West College).

Sure enough, I passed with damn near flying colors! Here is the print out of today's outcome:



So the cats were bad. That is the moral of this story. I now have a BAR certified swapped e30 and it feels so good! I'm glad that I could take care of this and I appreciated everyone of you who gave me advise on what to change.

I didn't have to change to a higher temp. thermostat which was nice.

Michelangelo's did a great job working with me and Chris Castro went out of his way to help me as well. Thanks to all parties involved!

[roguetoaster]

Glad you got it worked out. Now go enjoy your now legal car!