Page 2 of 3

Re: very lumpy start in cold weather

Posted: 10 Dec 2012, 18:29
by bigherb
Work the throttle a bit to simulate like you are driving.

Re: very lumpy start in cold weather

Posted: 11 Dec 2012, 11:38
by stevo1980
Done the test today everything seems as it should. Proper frosty outside too and it startyed no problem so i think the choke is working ok. On further looking and a bit of studying articles on here and other sites have found my thernostat is goosed, i assume this is why its using lots of fuel as it is a cold engine. Also noticed they dont kake them anymore but have found them on Brickwerks for 38 quid. Jobs a good un.

Re: very lumpy start in cold weather

Posted: 11 Dec 2012, 13:05
by bigherb
Yep a working thermostat makes a big difference in cold weather. The carburettor inlet warm air is taken from around number one cylinder without the thermostat it takes longer to warm up the carburettors.
The next thing to check is the inlet air preheating flap is working assuming you still have the original air filter fitted.
Start the engine when it is cold and pull the rubber pipe of the pre heater flap you should hear the flap inside drop down and there should be a vacuum present at the end of the rubber hose.

Image

Re: very lumpy start in cold weather

Posted: 11 Dec 2012, 17:30
by stevo1980
Ok looking at the pic above, i dont have the 2 little pipes coming off the air box and also the idle stabilizer is disconnected and plugged together. whilst driving today i noticed a couple of times the engine appeared to be running away with itself whist stopped, a quick blip of the throttle took the revs back down.

Re: very lumpy start in cold weather

Posted: 11 Dec 2012, 17:47
by bigherb
Take a picture of the engine lets see what you have got and need to remedy.

Re: very lumpy start in cold weather

Posted: 11 Dec 2012, 18:08
by stevo1980
ok will get one up tomo as im off to work now.

Re: very lumpy start in cold weather

Posted: 12 Dec 2012, 16:11
by stevo1980
Here is the layout of the engine.
Image
Image
Image

Re: very lumpy start in cold weather

Posted: 12 Dec 2012, 17:21
by bigherb
The pre heater flap has been bypassed for some reason. The diaphragm might have split, connect a bit of tube to the flap and try sucking you should not be able to suck any air. If it is good reconnect it as in my picture above you don't need plastic tubing you can use 3mm fuel/vacuum hose. Check you have a vacuum at the end of the hose if not then the thermostat in the air filter is blocked or faulty.

Image

Re: very lumpy start in cold weather

Posted: 12 Dec 2012, 17:39
by stevo1980
Do i also plug the stabilizer back in too.

Re: very lumpy start in cold weather

Posted: 12 Dec 2012, 17:48
by bigherb
You can try it but will probably find it's faulty that's why they are usually bypassed, they will run ok without it.

Re: very lumpy start in cold weather

Posted: 12 Dec 2012, 18:05
by stevo1980
Thank you so much for all your help, i will get it all sorted very soon and keep you posted. Thanks again mate much appreciated.
Steve

Re: very lumpy start in cold weather

Posted: 12 Dec 2012, 20:34
by jason k
as herb says leave the idle stab plugs well alone,

i would re route the vacc pipes to how they should be and see how it goes.

Re: very lumpy start in cold weather

Posted: 12 Dec 2012, 20:40
by stevo1980
Where would i get the T piece from, any car shop, halfords etc?

Re: very lumpy start in cold weather

Posted: 12 Dec 2012, 20:55
by bigherb
Yes they are standard parts like these ones.
http://www.ebay.co.uk/itm/3mm-Plastic-T ... 4cf4c08418

Re: very lumpy start in cold weather

Posted: 12 Dec 2012, 22:21
by faggie
steve you will never get brilliant fuel consumption if you run the auto chokes, did you fit a new thermostat and cable