Jump to content

Mysterious bogging down


Recommended Posts

Hi all,

I have a mystery for rollaclub's finest...

I've just dropped a freshly rebuilt 5k into my KE55, and had success for the first night of driving (about 45 km). Then I noticed a flat spot under medium acceleration. This got worse and worse, to the present, where it is undriveable--bogs down and shudders when trying to accelerate past 20 km/h in any gear, but will go ok with my foot to the floor. 

I've taken the carb (Weber 32/32) apart and cleaned all the jets, adjusted the flat level and checked the needle and seat. I've also changed the ignition points and checked gap and ignition timing. Initially I suspected water in the petrol tank, but having filled a bucket from the carb inlet hose, and inspecting the fuel being pumped through, it seems completely normal and un-gunky.

I'm a little lost as to what to try next--I thought of changing the ignition coil? But I'm not totally sure what these symptoms would point to as the next step. Any help would be much appreciated!!

Cheers

Jasper

Link to comment
Share on other sites

Members dont see this ad

Hi Jasper,

                  It could well be ignition or carburation, but it is a bit hard without hearing the motor under load.

1.  Does the flat spot feel like it is load related ?.  If so, it could be running on 3 cylinders, or a spark plug or lead breaking down under load.

2. Does this shudder feel like the ignition cutting out altogether, intermittently ?

3. If it is fuel related, it will feel more like a "starving" condition, without jerkiness (dying sound).

Have a look at the engine HV electics in the complete dark,, & look for any break down around or inside the leads.

Have a good look for leaks in the inlet manifold, where it may be leaking more air in.

Cheers Banjo 

Edited by Banjo
Link to comment
Share on other sites

Thanks for the responses guys! I ended up changing points and condenser chasing an electrical issue, and swapped the leads with a spare set I had, all to no avail. 

It did end up being a fueling problem, albeit a bit of a curveball! I posted the details with pictures in the thread below, but basically the little brass tube insert in the primary auxillary venturi had slid half a cm toward the air corrector jets, and was all but blocking fuel supply to the primary throat--I could only get the car going by pumping the throttle and so shooting fuel from the accelerator pump. 

Thanks again! The new 5k is running a beaut!

Edited by Wingsforwheels
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...