Technical Panda lack of power and juddering

[Torridon1]

Hi,
It's been a while since I bothered the forum with panda problems...
My 1992 Panda 999 CLX (non fuel injection) has started running very "lumpy" and struggles and judders under acceleration, with not normal rattles from the engine area and exhaust.
I would describe the car as feeling very " out of tune" almost like the timing belt has slipped a bit.
I found a leak in the fuel line between the fuel pump and the carburettor which I thought might have caused the problem, but that is replaced and the problem persists.
I suspect the car is using more fuel than it normally does, maybe as I have the choke out more to keep it going when stopped at traffic lights when the engine is only warming up.
I would be grateful for any advice on where to start investigating
Many thanks

 

[Torridon1]

Hi,
It's been a while since I bothered the forum with panda problems...
My 1992 Panda 999 CLX (non fuel injection) has started running very "lumpy" and struggles and judders under acceleration, with not normal rattles from the engine area and exhaust.
I would describe the car as feeling very " out of tune" almost like the timing belt has slipped a bit.
I found a leak in the fuel line between the fuel pump and the carburettor which I thought might have caused the problem, but that is replaced and the problem persists.
I suspect the car is using more fuel than it normally does, maybe as I have the choke out more to keep it going when stopped at traffic lights when the engine is only warming up.
I would be grateful for any advice on where to start investigating
Many thanks

Whoa there! I am reading Dragon Mans FAQs and have plenty of checks to do before updating you on this post.
Apologies for not checking the FAQs first

 

[Dragon Man]

to me it sounds like the vacuum advance diaphragm has failed on the distributor. usually you can rule out blocked jets in the carb if the choke affects the acceleration (usually it accelerates better with the choke pulled out if the jets are blocking up)

 

[Torridon1]

to me it sounds like the vacuum advance diaphragm has failed on the distributor. usually you can rule out blocked jets in the carb if the choke affects the acceleration (usually it accelerates better with the choke pulled out if the jets are blocking up)

Thanks.
So I have checked the vacuum advance diaphram by sucking air (no pipe handy so was lips to metal). My lung/spit capacity ran out before I could stop sucking air, so I assume this has failed and I am ordering a replacement.
I did also look/feel both the pipes described in Dragon Man's FAQs and they both seemed intact and not split (but I confess they looked tricky to take off from the back of the carburettor so was not a forensic check)
Is it safe to assume that replacing the vacuum advance part is straightforward? Anything I need to look out for?
Many thanks

 

[Dragon Man]

nothing really, you just kinda need to access the inside of the distributor to change the vacuum solenoid over. i will tell you that its more easy to do if you take the distributor off. just mark its position before undoing the 2x 10mm nuts that hold it on. that way you dont loose the timing. just be aware that the O ring seal will be quite old and its advisable to change it. though you can keep using the old one if its not split.
the arm on the end of the distributor shaft can be hard to pull of, but a good tog usually makes it come off.

hope this helps

 

[Torridon1]

nothing really, you just kinda need to access the inside of the distributor to change the vacuum solenoid over. i will tell you that its more easy to do if you take the distributor off. just mark its position before undoing the 2x 10mm nuts that hold it on. that way you dont loose the timing. just be aware that the O ring seal will be quite old and its advisable to change it. though you can keep using the old one if its not split.
the arm on the end of the distributor shaft can be hard to pull of, but a good tog usually makes it come off.

hope this helps

Thanks. I am waiting for the part to arrive and I'll report back on the outcome. Thanks again

 

[Torridon1]

Thanks. I am waiting for the part to arrive and I'll report back on the outcome. Thanks again

New vacuum component fitted and problem solved.
Do these fail gradually or instantly? I ask as the car seems more responsive now than it did before the very noticeable loss of power etc that caused me to post here originally. So maybe it was on the way out for a while or just some rose tinted recollection?
I think I now need to adjust the idle revs as it feels like it is revving a little high now
Thanks for your help on this. Much appreciated.