Mazda Rotary Club

General => General Technical => Topic started by: johnm on April 24, 2009, 09:37:33 PM

Title: MOT testing in Aberdeen
Post by: johnm on April 24, 2009, 09:37:33 PM
Hi all

I have an FD, Nov 1995 (full cat test) it has failed its MOT and retest, my attempts failed on either high CO or high lamba depending on revs, have replaced plugs, CO sensor, swopped cat etc, but nothing allows it to pass.  Going to set throttle position sensor, but not hopeful that will make any difference.

Any advise on a GOOD MOT garage near Aberdeen?

John
Title: MOT testing in Aberdeen
Post by: RotorHeid on April 24, 2009, 10:09:26 PM
Filik John,
it\'s difficult to tell what\'s cause your failed, try Taylor at lang Strach, they might able to analyse the problems.
maybe a wee fault like air pump!!
Title: MOT testing in Aberdeen
Post by: philiwily on April 26, 2009, 12:28:00 AM
How high is your co & hc. what mods you got?
Phil
Title: MOT testing in Aberdeen
Post by: the hat on April 26, 2009, 09:32:37 AM
hey buddy take it to mmc in culter just book it in for the test my emissions sheet for my s13 cofirmed that my car never saw a probe up the exhaust
Title: MOT testing in Aberdeen
Post by: johnm on April 26, 2009, 09:48:05 AM
CO 2.5 to 3.4 at 3000 rpm, HC 116 (within limits).  Had a retest and got them down within limits, but lamba was at 1.4, so failed.

Mod - cheap bast**d intake (RX7.com), racing beat cat back, standard ecu.

Will book in at MMC, see what comes back.

Made a few changes this weekend, ensured throttle butterflies were fully closing - they were not, idle speed had been set with using the screw on the side of the throttle body, now set with the by-pass system under the throttle body, disconnected the petrol catch tank under the throttle body, just going out to ensure the secondary injection and check valve are ok.  Have also confirm O2 sensor is working in closed loop control, on disconnect of the probe voltage is 0.998, over a period of 20 seconds, the voltage creeps down to 0.8, reconnect, leave for a minute and recheck voltage has again stabilised at 0.998.

John
Title: MOT testing in Aberdeen
Post by: johnm on April 27, 2009, 08:00:38 PM
Now have an mot certificate.

CAT test initially failed on lamba, asked the tester to take a look at the spec for a uk model rx7, loaded details in to the test unit manually, tested using those setting passed with ease, due to the extra allowance on the lamba.  Results of cat test, CO 0.03, HC 26 and lamba 1.2 (which is above the normal limits).

Things different from first test

1.  disconnected fuel fumes collection tank - mounted to the bottom two throttle body nuts, ran a pipe below the engine, blanked of the feed to the solenoid valve.
2. Cleaned the area around the throttle body butterflies to ensure throttle plates completely close, not closing seemed to stop the CO2 sensor going in to closed loop - no idea why???
3. Item not fixed - Also spotted the air injected directly in to the CAT (split air) was not was not flowing when removed from the CAT.  Went to check out the split air by-pass solenoid, normally mounted on the air control valve - but nothing was mounted nor did it look as it ever had, this may explain the slightly elevated free idle emissions.  If anyone has any ideas how this controlled, on a late 95 auto feedback would be welcomed.
4. Also found a small exhaust leak, this was also repaired, which will have helped bring down the lamba from the first test.
5.  Also modified the control of the air pump so it runs all the time, not certian if this helped or not

Used 5 Mile Garage at Kingswells - very helpful, went out of their way to help, even adjusted head lamp aim free of charge, did even mention there was an issue, just fixed it.

John
Title: MOT testing in Aberdeen
Post by: RotorHeid on April 27, 2009, 09:45:44 PM
f\'lik,
great news and start of happy summer motoring.:)
Title: MOT testing in Aberdeen
Post by: philiwily on April 27, 2009, 10:13:33 PM
Nice one mate.