unkown problem with car

[alicarv96]

i have a 1992 gt2 with ex engine and weber carb jetted correctly the fuel system is fine both fuel filters are clean and full and the tank is sealed but for some reason when going 60 or so the car will bog a bit sometimes it will be at a higher speed than that sometimes it will be much lower any help would be appreciated.

[MRMENDER]

I assume carb flange gasket is ok? Are you absolutely sure there are blockages in the fuel lines?
If so go back to basics. HT Leads plugs, Distributor cap & Rotor Arm, coil. The electronic Ignition module can problems similar to what you describe.

[alicarv96]

yeah fuel lines are fine we had them off stage by stage today to see

[duggers]

Speed is less relevant than throttle load, Bare in mind that fuel demand will be controlled by jets and possibly accelerator jets/pumps (don't really know webers that well).

[mark1gls]

Some cars seem to have problems with the Webber carb sending to much fuel back to the tank, try removing the fuel tank return and block it off, if any better it's worth restricting the flow back to the fuel tank, Ive read a welding tip placing in the fuel line works well. You do need to have fuel returning to the fuel tank so if you do remove it to test you must reinstall it.
Lots of threads on this site and the mk1 golf forum about doing this.

[gt11rocco]

Had the same problem especially on left hand going up hill corners (no idear why) but fully disconnected fuel return line and fuel vaporiser and now works a dream. All I did to try was joined the line going into vaporiser to the line on carb with 8mm copper couple clips small drive to see if any change and in my case jobs a good 1

[unknownmale]

Yeah, what mark said! Run a line from the pump straight to the carb and see if that helps. I added a t piece and put a schrader valve in the return line so that I could meter the amount being returned. Mine used to fall over itself when underload at about 3000rpm.

[alicarv96]

Can anyone post or link a picture as to how they have solved the problem so I can have a better idea of what to do

[mark1gls]

Found this.
viewtopic.php?f=12&t=15397&p=108440&hil ... rn#p108440

Any help?
viewtopic.php?f=12&t=12885&hilit=restri ... n&start=30

[Nate]

If the weber has been in service for any length of time, check the inlet filter (17mm nut directly under the fuel inlet) these are meant to be cleaned at service, but from the cars I've seen over the years, I don't think they are very often. Possibly due to the number of people who confuse "service" with "oil change"

[alicarv96]

does anyopne know the inside diameter of the small fuel return line is?

[go-for-it1]

The return line restrictor which is built in to the swirl pot return spigot is about 1.2mm, so the pipe diameter is irrelevant so long as the restriction is about this figure. New swirl pots from after market sellers don't generally have the correct restriction size so allow more fuel to return which starves the carb when under load.