Emission fail 2nd time thru

Jacksone30 · Post by **Jacksone30** » Wed Nov 09, 2011 6:36 am

SO I had these readings first time on my 89 325ic - NJ Inspection results
Idle
HC 285 (limit is 220) Fail
CO 0.73 (limit is 1.20)

High idle
HC 94 (220 is limit) Pass
CO 0.68 (1.20 is limit) Pass

Car had a little sputter at idle (when warm only- smooth when cold) so i did the following:

I adjusted the valves and pressure cleaned the fuel injectors.
New pintle caps (not OEM ones with the barbs)
Did not replace screens in the injectors - but they were flowing good.
New valve-cover gasket - new breather hose (no leak n the old one)
I don't think i have a vacuum leak
BTW - Valves were tight and injectors were very dirty.

I had these readings the second time through
Idle
HC 252 (limit is 220) Fail - lower than first time so improved
CO .75 ( limit is 1.20) Pass - almost same as first time

High idle:
HC 221 (220 is limit) Fail (by one freaking point)
CO 0.62 (1.20 is limit) Pass

After adjusting the valves and cleaning the injectors the sputter at idle is all but disappeared - extremely slight can't feel it like before. Tailpipe sound is very smooth.

Q: So why did the HC at high idle go up so much on pass #2 ?
Q: How to get the HC down more at low idle?

Temperature is good - gauge in the middle
New O2 Sensor (Bosch)
Plugs a year old.
Air filter less that 3K miles
Car mileage is 103K ( ODO broke at 101)

Gonna check fuel pressure today.
I hope its not the cat -

Car was running rich for a while ( 1500 miles maybe) with the sputter you could smell the gas a bit at the tail pipe. No gas smell after the valve/injector service

At the moment i filled it with high test and am running a bottle of "Guaranteed To Pass" hoping for a miracle.

If its a vac leak -dammed if I can find it.
Any ideas would be much appreciated.

Thanks

victory1auto · Post by **victory1auto** » Thu Nov 10, 2011 7:08 am

As evidenced by the CO reading, the motor is running rich. Don't let the fact that the CO passed fool you [The standard used to be 0.5%, and even that was very lenient for a car with a catalytic converter.].

You do have the classic emissions signature of a motor with a vacuum leak. The M20s are known for leaking intake-manifold gaskets at the individual runners. So check this out very carefully with an unlit propane torch or other suitable vacuum-leak finder.

Have you checked the fuel pressure?

If you know of a shop that has a "smoke tester", have them check the intake tract for leaks.

Vic

m20power · Post by **m20power** » Thu Nov 10, 2011 7:24 am

Inspect the plugs, looking for signs of a misfire. If they look OK, then I suspect that you have a bad/leaky injector. Perhaps a problem that was worsened by the cleaning process. You could pull them and leak test, or swap in known-good parts.

HTH, Bob

Jacksone30 · Post by **Jacksone30** » Sun Nov 13, 2011 8:05 am

victory1auto wrote:As evidenced by the CO reading, the motor is running rich. Don't let the fact that the CO passed fool you [The standard used to be 0.5%, and even that was very lenient for a car with a catalytic converter.].

You do have the classic emissions signature of a motor with a vacuum leak. The M20s are known for leaking intake-manifold gaskets at the individual runners. So check this out very carefully with an unlit propane torch or other suitable vacuum-leak finder.

Have you checked the fuel pressure?

If you know of a shop that has a "smoke tester", have them check the intake tract for leaks.

Vic

Thanks guys - I took it to a local shop that does inspections. A tweak to the AFM passed it and I got the sticker. Good for 2 more. I'll continue to look for a vac leak-fuel pressure was spot on. His reading was like 225 before the tweak so it wasn't much of a cheat.

There is just a tiny bit of roughness and intermittent stumble in the idle. Wife thinks I'm crazy.

I'm betting on the intake manifold gasket or the oil drain tube. Since the plugs are gray it is most likely a lean misfire. I'll keep searching. I read it's not so difficult - just a PITA to get the oil tube set on re-install.

Need To replace the ps pump getting noisy and weak power steering. Anyone have a vickers pump?

victory1auto · Post by **victory1auto** » Sun Nov 13, 2011 11:14 pm

Thanks for the follow up. Can you please post the final emissions numbers for CO HC O2 CO2?

Thanks.

Vic

Jacksone30 · Post by **Jacksone30** » Thu Nov 17, 2011 5:42 pm

victory1auto wrote:Thanks for the follow up. Can you please post the final emissions numbers for CO HC O2 CO2?

Thanks.

Vic

Sorry VIC i did not get the final numbers - just the sticker.
I'll call him and ask if he retained them.

Tim

victory1auto · Post by **victory1auto** » Fri Nov 18, 2011 6:29 am

I am told that if you go to the NJMVC website, you can enter the VIN of your car and get the inspection report.

Vic

Jacksone30 · Post by **Jacksone30** » Tue Nov 29, 2011 11:33 am

victory1auto wrote:I am told that if you go to the NJMVC website, you can enter the VIN of your car and get the inspection report.

Vic

Took a bit of stumbling around on the DMV website but I found it

http://njvir.appsolgrp.com:8010/VIRPrin ... Search.jsf

Mode: IDLE - PASS TEST RESULT:
HC ppm 152 (220 -standard)
CO% 1.14 (1.20 -standard)
CO2% 13.2
O2% 1.8

Mode: HIGH IDLE - PASS
HC ppm 54 (220 -standard)
CO% 0.50 (1.20 -standard)
CO2% 13.9
O2% 0.6

So i am told (bimmerforums) the tiny little bit of stumble in the idle may be attributed to the platinum plugs i am running - and i should run NGK copper plugs. Cap and wires are new, certainly not the trouble.

Just for the hell of it i will soon replace the intake manifold gasket and oil tube o-rings since they may be leaking.

Then i will move to rebuilding the rear end sometime this winter. The gasket on the pumpkin (pass side) has a slight leak. There is some whining noise back there too- not sure - might be the fuel pump.