reducing emissions

Sun Nov 20, 2011 10:38 am

Hey as some of you may know one of the fails frm my mot was the emissions. How do i lower them?? Its a 87 325i so no CAT. Just had front silencer replaced too. only thinkg i can think off ig a good blast up the road and some sort of petrol addative.

Sun Nov 20, 2011 10:55 am

Chances are it's running a bit rich. Grab a cheap multimeter and test your Blue Plug:

http://www.e30zone.net/e30zonewiki/index.php/Blue_Plug

It could also be leaky or dribbly injectors

Sun Nov 20, 2011 11:13 am

Short answer is keep it in good condition. An E30 should have no difficulty in clearing the emissions hurdle by a mile.
If it fails, or comes anywhere near failing, it's a very sick E30 in need of attention, and almost certainly not delivering its potential in either MPG or performance either.

Sun Nov 20, 2011 5:09 pm

the co level was 3.60%. Last year it pased at 1.27% with a head gasket leak. but i have changed the engine since then, so as you say brian its sick.

Just changed the blue plug. Was serviced in the summer with all new stuff. oil/filter, plugs,leads, air filter ect.
I do suspect a injector or two not working properly tho. What other things need looked at to bring down the emissions?

Sun Nov 20, 2011 7:36 pm

Compression/leakdown test to check on the mechanical condition of the engine, rebuilt injectors, clean air filter, check the blue temp. sensor and its wiring, check the TPS is working correctly, and that the throttle stop has not been altered, then get the CO set to 1%.

Sun Nov 20, 2011 9:07 pm

Cheers again brian. I'll get the compression done tommorow. the injectors rebuild sounds a bit expensive :S need to get that done in a week for retest or i'll have to frk out again. defo need to check the tps and the blue temp sensor/ wiring i'll borrow someones multi meter. And the throttle stop should not have been touched as its the same inlet ect but i'll still check it out. thanks always a great help.

Sun Nov 20, 2011 9:14 pm

mosh86 wrote: the injectors rebuild sounds a bit expensive .

£60 plus carriage, if you look in our traders section!
TPS on an E30 can fill up with oil, which stops the idle switch working.

Sun Nov 20, 2011 9:24 pm

Thats actually not to bad. i was thinking around £20 per injector. Just read up about the tps. will try test it tommorow.

Sun Nov 20, 2011 11:39 pm

For the TPS have a quick look at my thread in the tech help section, Mr Moore, Pacerpete plus others put some really good advice on there for diagnosing issues.

Mon Nov 21, 2011 6:04 pm

Rtaylor2208 wrote:For the TPS have a quick look at my thread in the tech help section, Mr Moore, Pacerpete plus others put some really good advice on there for diagnosing issues.

Cheers i'm sure i was reading your thread as you wrote that.

Injectors being sent off tommorow morning.

Might have to wait till the weekend where i have decent light to do the compression test ect

Tue Nov 22, 2011 6:19 pm

Just done the compression test all were in between 11 and 12 bar. i'm sure this is ok.?? should be getting a multi meter tommorow

Fri Nov 25, 2011 4:39 pm

tested my blue plug. 3.605 k ohms when cold and think it was 455.5 when warm.

Fri Nov 25, 2011 4:47 pm

Blug Plug reading sounds about right, Did you check at the ECU end as well as the sensor on the engine.

Fri Nov 25, 2011 6:19 pm

That's too high for the hot reading, assuming the engine was fully up to temp.

Fri Nov 25, 2011 7:04 pm

it may not have been entirly up to temp. might have been 355 but i was frozen from work and rushed it. was thinking to myself that 455 sounded a bit high thats why i posted. checking the ecu plug tommorow tho so i'll double check the blue sensor.

Sat Nov 26, 2011 4:06 pm

checked the plug when the engine was up to full temp. was around 260. several mins later found out what pins to connect on my ecu (motronic 1.1) it was reading 385 then quickly went to check plug again o get accurate reading and it was 390 there so i assume the ecu is picking up the signal.

Sun Nov 27, 2011 6:15 pm

fitted cleaned injetors today and drilled a hole in he bottom f the tps to get gunk out. None came out so gave it a wee spray of cleaner. Filled up coolent again got all the air locks out (i think) took it for a short drive and its idleing at 800 rpm for the first time since i got the car. Must of done something right i hope. i'll get the garage to look at the other hings i nees for the mot then hpefuly get it passed.