[dubsteez79]

just got my 84 mk1 GTI carb swap complete. It will crank and idle fine. I am having a really bad bog when I give it throttle. If i pump it a couple of times and keep the rpms up it will rev like normal but from idle, it wants to bog and die. It does idle pretty solid but isnt as smooth as I would like at the moment. Its a weber 32/36 with a 'magnum flow' intake that looks similar to the redline setup. The carb was purchased new and put on a 1970 toyota 1.9L engine and it ran fine while it was on that. I have cleaned the carb out by completely disassembling and cleaning with carb cleaner and air. Nothing was plugged. The accel pump ball is moving freely. Replaced the accelerator pump but initially tried to install backwards which made it stretch. After I took it back off, it didnt look like it was leaking behind it but im still uncertain as to whether it is ok. I have checked for vacuum leaks with smoke and cant find any. the injector shrouds are tight and new seals on the injectors(for sealing off holes in head). Is there anything other than the accel pump that could be causing this? Im out of ideas until the new accel pump comes in.

 

[DbilasTDI]

Lack of fuel in secondary circuit?

What is your initial timing set at? I would go for 8-10° initial

What cam?

what fuel pump

fuel pressure?

 

[dubsteez79]

The bogging is happening on initial throttle,way before the secondaries open. when they open its a little lean but not terrible. I have an AFR gauge set up. When I blip the throttle, there is a delay and it catches up in a second or so and revs like it should. I have been reading that it may need some more timing.

Cam is a G grind.
Timing is at stock CIS setting.
Fuel pump is a summit low pressure pump set at 2.5-2.75 psi with summit regulator.

 

[dubsteez79]

advancing timing to around 10 degrees helped quite a bit. the dead spot is smaller and it drives without falling completely on its face. The main circuits are definitely too lean too. AFR around 17 and 18 when the mains take over. primary and secondary. They are 130 primary and 140 secondary now. air correctors are 165 primary and 160 secondary.

 

[dubsteez79]

any more input would be appreciated. im planning on getting the 20pc number drill set from harbor freight and redrilling my mains. only hoping that this will be the cure.

Sent from my SM-G930V using Tapatalk

 

[DbilasTDI]

I would call Pierce manifolds and

#1 see what they say

#2 buy a jet kit from them

drilling jets does not produce a perfect hole always - difficult to smooth out passages.

 

[srgtlord]

Im thinking fuel pressure is incorrect. Carbs need proper pressure to operate.

 

[DbilasTDI]

you need enough pressure to keep the bowls full. If that is not happening, you run out of fuel at some RPM, not idling and initial take off.

I would call Pierce manifolds and

#1 see what they say

#2 buy a jet kit from them

 

[Alderstorm]

Perhaps your pump jets are too large and you're getting too much fuel on throttle initially which is bogging it down?