flat spot problems

Need some help with a technical problem - ask away and let's see if we can all help.

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green bogey
DDK Seasoned Poster
Posts: 28
Joined: Tue May 03, 2005 9:52 pm
Location: Worcestershire

flat spot problems

Post by green bogey »

hi guys
i have installed a 2.4t 911 engine in a baywindow camper but have flat spot trouble when the engine is idling on tickover it runs a treat but when i press the throttle a flat spot accurs for a split second then the engine revs quite happily also when i blip the throttle a couple of times it stalls , the engine has weber carbs that have been rejetted ,a bosch dizzy with a msd 6al box , a facet fuel pump set at 4 psi, new points ,new condenser,new rotor arm ,and cap all the plugs & leads are new
any help would be much appreciated
cheers
andy
Gary71
Nurse, I think I need some assistance
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Joined: Wed Mar 31, 2004 1:27 pm
Location: Cheshire
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Post by Gary71 »

Hi,

Sounds like the accelerator pumps are not working or are set up wrong. If you look down the carb throat (if possible in a camper installation?) you should see a squirt of fuel at each venturi when you open the throttle.

The other thing I found with my Zeniths (similar to the webers I understand) was that if set up too lean at idle it would fluff and almost die when you blipped the throttle. Open all the idle mixture screws a couple of turns and see how you get on.

Most likely it is the accelerator pumps though. Have a look at the Zenith info on my site and it should point you in the right direction for set up. 8)

Sounds like a cool camper, any pics of the installation? :)
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