failed MOT on emissions

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big red bus
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Post by big red bus »

have checked autodata and here is the steps to adjust co%,
For adjusting co and idle speed you must first disconnect crankcase breather hose and clamp it of (use brake hose clamp). Then disconnect idle speed stabilisation connector at the coil (single terminal, trace wire from isv valve to plug and disconnect) Then disconnect DIS unit plugs and join together (think its the unit attcached on th n/s by the igntion amplifier. Then under these conditions adjust the co by turning screw on airflow meter and also idle speed may need adjusting to compensate for co level being adjusted. this is a large flat headed screw on the throttle body. Hope all this helps, cheers.

KarlT
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Post by KarlT »

I think your problem will be the 2.1 injector system. Too much fuel.

Friend just tuned mine. As BRB says.

Mine was reading 4.6, MOT pass might be 3.6 but Haynes says it should be 2.0 +/- 0.5
Adjust at air-flow meter screw. Friend says it is common for this be faulty & adjustment impossible. Then new air-flow meter needed.

Make sure you've got the three point spark plugs & new air filter.

Good luck.

Simon Baxter
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Post by Simon Baxter »

don't go turning any screws if you don't understand what you are doing or if you dont have a gas anylyser to check the results of your actions, thats just daft.
Why not just let the garage sort it?
If the CO is out, chances are there is a problem as CO readings don't go sky high on their own, it will be due to an underlying fault, probably coolant temp sensor, dodgy wiring etc.

Fix the fault, don't remedy it's effects.
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bigfish
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Post by bigfish »

I'm booked in for a tune first and formost this coming tuesday at Injectors in Stockport, then back for the ticket after getting back to Preston :D

the van seems to be running fine, no hesitation in acceleration, no flat spots, not that bad consumption. the reason i need to know about the screws etc is to get the analyser value down to pass the MOT, obviously i'll take note when adjusting things if req'd and undo everything back to as is after i get the ticket.

But you are right, i'm not just gonna keep tweaking until it runs like a bag of spanners. :rollin

cheers
Brad
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bigfish
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Post by bigfish »

:D happy days. I got it tuned at Injectors in Stockport and they got the emmisions down to 2.0, so it flew threw the MOT, bit more sluggish if that's possible, but the fuel consumption has improved, so bring on the summer!! 8)

thanks for the help

Brad
take it easy - 3447

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