Hydrocarbons

[minimatan]

Well, after a year (!) my car is on the road with new valves and a few other bits. Nothing fancy, but when your Dad's a mechanic, well, you sit at the back of the queue!

They have been adjusted and the emissions are 300 hydrocarbons, which apparently is very good.

Can someone explain to me what this means and how it translates to CO2 emissions that are now quoted with all new vehicles?

[pacerpete]

300 is actually not great . A good running 325 should have a HC reading of 150 or less and CO of 1% ish . Tight valve clearances, air leaks or a lean mixture will lead to a higher than normal HC reading.

[minimatan]

Oh. *bubble burst*

[minimatan]

Hopefully it'll clean up after a bit of running and some of the fuel injector cleaner added to the fuel tank by my cunning mechanic!

[Grrrmachine]

The only thing a fuel additive will clean is your wallet. Get the injectors removed and send them off to Injectortune.

[Brianmoooore]

The only thing a fuel additive will clean is your wallet. Get the injectors removed and send them off to Injectortune.

THIS!! The best investment, BHP/MPG for your £ you will ever make.

[minimatan]

Thanks guys, I'll get my head around the advice and where I stand in the general context of what needs doing to the car, and I'll take it from there.

A quite glance at their website makes it seem quite reasonable, so I may get it done soon, when the rear subframe mounts are being replaced.

[minimatan]

With regards to the injectors, would they be the reason that the sport is very 'jerky' at low revs in 2nd gear when keeping a steady throttle in traffic?

[Brianmoooore]

With regards to the injectors, would they be the reason that the sport is very 'jerky' at low revs in 2nd gear when keeping a steady throttle in traffic?

Very likely to be one of the factors involved.

[minimatan]

The kind of 'kangaroo' effect? Anything else that it could be?

[Brianmoooore]

Air leaks, TPS, and the effects of the uninitiated playing with every adjustment that they shouldn't be, to try and cure the kangaroo effect.
Injector refurb is the place to start.

[minimatan]

Thanks

[Speedtouch]

Alot of 1980s fuel injected vehicles have this 'kangarooing' effect, because they partially cut the fuel off when coasting along in traffic, so it is constantly pulsating the fuel flow.

A chip can help improve the driveability quite significantly, by eliminating the un-needed sections of the program on the standard chip.