Low revs stutter

[nickpan]

Hi,

I have a Tiger super cat with a 1.8 zetec engine w/ side draft webers. I believe it has an emerald ECU...

Only just purchased the car so still getting used to it - however, there's a distint rough patch/stutter in the low revs of each gear. Especially in gears 1-3. It does smooth out after about 4000 reves but prior to that, the engine is quite jerky and irregular.

I know this could probably be a million things but any general advice? Has the ECU not been configured properly? air flow issue?

Many thanks!

Nick

[Mr2Mike]

Have the carbs ever been correctly jetted and balanced? Most cars running DCOEs aren't IME.

[silverian535]

some one once said that 90% of all fuel problems are actually ignition problems, so I would start with bunging new plugs and leads on, and checking all the electrical connections.

Having said that, DCOEs can if not set up properly have a problem with transition from the idle jets (used up to 2000 to 3000 rpm) and the mains.

Also get the fuel pressure checked out as it could be over pressure, and hence over fuelling at low revs.

My idle jets are too rich, and have a slight stutter at about 2200rpm.

Could be worth checking the basics and then getting it on a rolling road.

[nickpan]

Excellent - thanks guys.

[funwithrevs]

Yeah, check the basics.

I had something similar when the main HT lead was falling out of the distributor, amazed a spark was getting to the plugs at all when I saw how wobbly it was but modern electronics can hide all sorts of woes.