MOT fail

[Kevin Garrod]

It failed on handbrake efficiency which I should be able to sort out and emissions, way over the 4.5% allowed (7.2% I think)

I've never had problems with emissions before I wonder if Stagdad's airbox is causing a restriction? What else should I look at? plugs? timing?

(Bear in mind I have a four barrel weber, they are not supposed to go out of tune)

[Andy Rundell]

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sorry to hear about that Kevin...... i'm not very well up on mixture adjustment of 4-barrel Holley/Webers but i'd have thought there must be some lean/rich adjustment available.

My usual quick fix would be to run without an aircleaner just for the mot, the extra air usually helps, what are your plug gaps ? - if you are running electronic ignition and a coil that isn't on its last legs try opening out the gaps by another 5 thou, the bigger spark should give a slightly more complete burn.

i'm sure others will have some better advice re the Weber

cheers..........Andy

[dasadrew]

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If the value is measured at idle in UK, just weaken the mixture with th adjustment screws on the Webers. It only affects the idle mixture as the fixed jets do the rest, so you won't be burning holes in pistons or whatever.

[Stagdad]

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Hi Kev,Just to let you know mine cruses at 16:1 with the airbox so no problem getting enough air in it and pulls well up to 100mph(didn't want to go any faster).

Cheers Steve

[flying farmer]

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The airbox will not be causing a restriction at idle, or it wouldnt go at all at revs.

Don't know about the weber, but the holley had two idle mixture screws, one for each side. Another possibility of course is that it is suffering from a faulty needle valve and the float chamber fuellevel is too high, just like strombergs

Neil

[Kevin Garrod]

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Thanks for the input, I'm going to whip out the plugs, just to see what they look like.

I can't see why the emissions have changed so much since the last MOT, as I said the only thing that has changed is the airbox. Hopefully a fiddle with the mixture screws at the MOT station will get things sorted.

On the plus side my welding of the the floor pan passed scrutiny!

[stagmuffin]

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my h/brake is u/s also just bought new levers and self adjusters from robsport £70:shock:but worth it the old levers i welded up the profile twice .the stag h/brakes are **** any way.mixture cant be much though it is checked at idle so maybe som adjustment or as flying farmer said.

good luck steve.............

[staggering]

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Kevin - suprisingly i had emission fail on an MOT when all others were ok - turned out to be coil breakdown causing weak sparks and unburnt fuel - may be worth a check and simples to replace - good luck

[stagwingnut]

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hi kevin ,my 1996 merc sl 320 just failed mot on emissions ,it turned out to be a faulty ignition coil ,therefore unburnt fuel !! changed the coil , then passed no probs cheers Graham

[Kevin Garrod]

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Well I've sorted the brakes (I think) the self adjusters weren't self adjusting but it seems that's quite normal, a lot of fiddling around to get the handbrake working without binding.

The plugs were a little sooty so I gave them a clean up and checked the gaps (0.035"), I've ordered a sports coil from LD parts. I just hope I can find the time to re- test before the 10 days are up.:?

[Rubce]

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Hi All

Whats the cut over date from the simple "visible smoke test" to the % emisions test?

MY 1971 Stag used to just have the smoke test and so does our 1973 GT6. I notice that Kevin's 1977 Stag was failed on the % emisions.

When I finally take the 1974 Resto Stag along for its MOT which will be subjected to?

Cheers

Bruce

[Stagdad]

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Rubce wrote:

Hi All

Whats the cut over date from the simple "visible smoke test" to the % emisions test?

MY 1971 Stag used to just have the smoke test and so does our 1973 GT6. I notice that Kevin's 1977 Stag was failed on the % emisions.

When I finally take the 1974 Resto Stag along for its MOT which will be subjected to?

Cheers

Bruce

74 your ok Bruce .75 onwards for co test

Cheers Steve

[Rubce]

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Stagdad wrote:

74 your ok Bruce .75 onwards for co test

Cheers Steve

Great news:dude:. Thanks Steve

Bruce

[Bob Heritage]

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It's 'P' reg onwards- August 1975, my 'N' reg March1975 is exempt

[Ian B]

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Strombergs are easy to adjust and get through the MOT emission's test, mine have passed for 33 years (with adjustment admittedly)