loss of power

[avant-garde]

Hi all, I know that this has been talked about a lot. I've read the forum posts and I still need help.

I have a 2.0l CU engine air-cooled 1982 bus and I am still having trouble getting up hills and accelerating etc. I've had my VW mechanic for the last year trying to sort the problem out and still no joy.

When I put my foot down on the gas pedal when going up a slight hill the van doesn't want to know. I'm lucky if I can get 20mph with my foot to the floor. If I lift my foot slightly off the pedal then it seems to want to 'go' ...so I am constantly feathering the accelerator pedal - still can't get over 25-30mph though. All this in 2nd gear ...if I try putting it in 3rd gear with the momentem from 2nd the van just slows right down...back into 2nd.

The butterfly flap on one of the carbs is stiff and the spindle is slightly bent. The mechanic straightened it out the best he could.
Constant oil leaks from pushrods to oil pump to oil strainer. Constantly fitting new seals etc - but again no joy with the performance.
Drilled two small holes in the fuel expansion tanks to eliminate a possible vacuum problem but that has made no difference with the loss of power/acceleration.
Fuel filter replaced.
Timing checked and carbs checked by the mechanic and as far as he can tell - no fault there.

He thinks it's a fuel starvation problem.

I've replaced the fuel pipes, in-line fuel filter etc - no joy.

When I pull off the fuel pipe from the tank there is no petrol coming out even though the tank is 1/4 full. Is that normal or should the fuel be gushing out?

I was told to try fitting the fuel pipe to the other outlet pipe on the fuel tank to see if that makes any difference. Before I pull off the bung on the 'pavement' side of the petrol tank can you just confirm that that outlet pipe is indeed an outlet pipe and not an inlet pipe?

I don't know what else to do - any advice will be greatly appreciated and in turn passed on to my VW specialist mechanic.

Many thanks.

[avant-garde]

Sorry forgot to mention a new fuel pump also fitted next to fuel tank - 3psi.

[dplum]

did the mechanic check the little fuel filter inside the carb? it doesn't seem like it will take much to block this up a bit

[fullsunian]

did the mechanic check the little fuel filter inside the carb? it doesn't seem like it will take much to block this up a bit

I dont think you will find said filter on a 2 litre air cooled carb set up...
It sounds like you need to get back to basics....Compression test first, then if all good check and set your igintion timing. After that its time to sort the carbs, clean them out, balance them and reset the mixture. Once that's all done correctly it should run fine

[avant-garde]

Hi dplum, the carbs are solex and they don't have them...only the Pierburg ones have them.

I've stuck a screw into the inlets and couldn't get anything out so I guess the little cone filter is just on the Pierburgs.

[avant-garde]

Been advised to buy DLRA 36 or 40 carbs. Has anyone any experience of these carbs?

[81AirCooled]

I don´t know if you´ve read my thread on power loss but make sure the timing is right. The garage that rebuilt and balanced my carbs insisted the timing was right despite power loss and my request to check over the phone. It´s appears they were trying to con me into an engine rebuild so ask the mechanic to check it´s at 5° ATDC and that it advances properly to around 40° BTDC - all vacuum hoses attached.

It wasn´t until I actually insisted on those settings that I actually had any power back.

[avant-garde]

I will mention that to him when I take the bus over on Thursday. I called him today and asked him about starting again from the basics - compression tests, timing etc and he told me that they had it all set correctly. I shall ask him again to check before I spend my money on carbs.

Thanks for that.

[kevtherev]

Dellorto DRLA carbs are the rolls royce of carbs and because of that command a high price... even second hand.

36's would be my choice, though gsmoke suggests 30's for a more usable power band lower down the rev range.

[sarran1955]

Hello,

Check your dizzy diaphragm.

I won't go into it,

Hew one not dear

Make sure the new one has the same number of fixing holes.

Cordialement,

[jason k]

Dellorto DRLA carbs are the rolls royce of carbs and because of that command a high price... even second hand.

36's would be my choice, though gsmoke suggests 30's for a more usable power band lower down the rev range.

i ran 36mm dells with no issues whatsoever. if you need any info just ask

[john1]

I don´t know if you´ve read my thread on power loss but make sure the timing is right. The garage that rebuilt and balanced my carbs insisted the timing was right despite power loss and my request to check over the phone. It´s appears they were trying to con me into an engine rebuild so ask the mechanic to check it´s at 5° ATDC and that it advances properly to around 40° BTDC - all vacuum hoses attached.

It wasn´t until I actually insisted on those settings that I actually had any power back.

Can I jump in for a wee steal on this thread as Im just going to set my timing?
Can I just confirm all Vac hoses should be attached, is this on the Dizzy also?



I had a problem with my Vac advance that gave sim problem, hope you get it fixed mate, keep us posted please?

[81AirCooled]

All vac hoses have to be attached and the vac can needs to work too though. If it doesn´t then the timing needs to be set differently but someone else´ll need to tell you what as I don´t know.

[LeeCarey]

Had the same problem, after replacing the diaphragm in my weber carb all was back to normal

[elmo makaroy]

BEFORE you try anything that has been mentioned can i just say that i had this same problem,

your tank outlet pipe is blocked! if you disconnect the fuel pipe coming from the tank fuel should pour out averywere!

i had the same problem after running low on fuel, i have swapped the fuel pipe to the otherside outlet from the tank and the problem is now sorted but i know that i need to get a new tank when i have the money!

please try this first as i drove my Aircooled for 5 months with nearly no power at all untill i did this, now i cruise at 75mph easily