weber carb

Honest John Back Room » Technical matters
View Threaded
Tue 8 Jul 2003 17:29
weber carb - triggermad
Hi guys, i have a '88 1.6 scirocco, which has just been fitted with a new weber 32/34 dtml. When trying to adjust the CO content, it jumps from 5% to -2% with a eighth of a turn of the mixture screw. Figuring it to be an air leak, i removed the intake manifold and replaced the gasket, but the problem is still there.Any ideas?
Reply | Report as offensive | Link
Tue 8 Jul 2003 17:50
weber carb - David Lacey
This is one for Adam (Tune-Up) but why has the carburettor been replaced? There might well be an underlying fault still present.
Reply | Report as offensive | Link
Tue 8 Jul 2003 18:27
weber carb - Adam Going (Tune-Up)
Thanks for that David - I think !!

Trigger,

Have never seen a MINUS CO reading - suspect the meter on that one ! However, the sysmptoms do indeed suggest an air leak. having replaced the manifold gasket the 3 favourites are
1. The rubber block mounting carb to inlet amnifold
2. The brake servo connection at N/S of inlet manifold
3. The distributor vacuum unit
Let us know what you find on those and we can go from there !

Regards, Adam
Reply | Report as offensive | Link
Tue 8 Jul 2003 19:42
weber carb - triggermad
Adam,
Have replaced the mounting block, the rubber pipe to the brake servo and sprayed easy start fluid around the distributor vac unit, which had no effect at all. The CO unit is just a Gunsons machine and not highly accurate but should do the job. Have noticed a good amount of water vapour coming out of the exhaust with it fully warmed up, but water level in the reservoir is not dropping. The carb was replaced due to the 2E2 giving me several problems, but the weber solved some, but not all. It will idle alright, but at part throttle it starts to miss and sounds like fuel starvation. I think theres more than one problem here. Any help will be gratefully received, or if not, any one fancy a bit of work!! Cheers
Reply | Report as offensive | Link
Wed 9 Jul 2003 08:33
weber carb - Adam Going (Tune-Up)
Well done for dealing with the mounting block and the servo hose, but please don't ever try testing a distributor vac unit by spraying anything combustable at it - you were very lucky not to have a nice little bonfire there, as the dizzy is just full of sparks looking for something to set fire to !! Test the vac unit by applying vacuum (either from a vacuum pump, or by sucking on an appropriate piece of rubber pipe) - you should see the baseplate rotate and it should hold vacuum indefinitely.

Wouldn't worry too much about the water vapour, so long as coolant level is stable. Does the engine rev freely to max (on the road, NOT at kerbside !!)on full throttle? If so fuel supply problem less likely than partial blockage of primary main jet. This can happen due to manufacturing swarf, and it is worth removing all accessable jets and giving everything (jets + drillings) a severe going over with aerosol carb cleaner. Also worth checking float level - if you need spec for this contact a Weber dealer.

If you do decide to call in some help, where are you geographically? I or someone else on the site may be able to recommend.

Regards, Adam
Reply | Report as offensive | Link

From which small car to buy at which price point to the best UK-built cars, our Top 10s have the lot. Click now for your shortlist.

Unsure of what to buy? Our Top 10s are here to help you....