cold start / rough on acceleration

[paul_jw]

hi, my 200 has a problem which i thought would go away with the replacement of the fuel filter but hasnt.

on a cold start, it takes a good few cranks to get it going, and will cough and fart until it eventually catches. then when it does go it will idle, but as soon as you put your foot on the accelerator it dies.

it seems as soon as i introduce air into the equation thats when it cuts out.

after about 5 minutes of gentle throttling it will run fine, and gets up to temp fine too.

ive replaced plugs, air filter, rotor arm, coolant, thermostat, fuel filter and ive put an inline filter next to the carb to monitor the condition of the fuel.

can anyone give me any ideas?

 

[paul_jw]

bump anyone?

its a pierburg carb.

unplugging cts makes no difference.

took the autochoke apart and moving the rod makes no difference.

im at my wits end!

 

[Brian WH]

Sounds like fuel starvation. Have you tested the fuel lift pump and checked the fuel lines for signs of air leaks?

 

[paul_jw]

I fitted an inline fuel filter just before the carb so i can monitor the fuel, and its clean, always full, and i cane see any bubbles.

Should these filters be primed before fitting or will it prime itself?

Ive had the carb off today and had a play with the autochoke to see if its at fault, seemed ok so its going back on in daylight tomorrow.

 

[paul_jw]

Sounds like fuel starvation. Have you tested the fuel lift pump and checked the fuel lines for signs of air leaks?

Ive just put some clear pipe between the carb and the bay inline filter and its not a continuous supply of fuel, more like fuel-gap-fuel-gap etc etc.

How do i check the lift pump?

Ive had a good look round the hoses and all the clips are tight, but i would have thought air getting in would equel fuel coming out?

Thanks
Paul.

 

[Brian WH]

Ive just put some clear pipe between the carb and the bay inline filter and its not a continuous supply of fuel, more like fuel-gap-fuel-gap etc etc.

How do i check the lift pump?

Ive had a good look round the hoses and all the clips are tight, but i would have thought air getting in would equel fuel coming out?

Thanks
Paul.

I would firstly removed the inline filter to give a clear run from pump to carb, thus eliminating any restrictions.
Air in the pipeline drains the pipe overnight leading to starting difficulties as air/fuel is being delivered to the carb. The air leak could be in the pipes or in the carb itself, due to bad seals. Once the engine has warmed up and the fuel is flowing properly then everything runs OK.
The lift pump you can check as you did before without the filter it should deliver a constant flow.

I don't want to say this but constantly taking off and putting back carb and fuel pipes is what causes air leaks.

 

[fisheggs]

Sounds like air/vaccum leak.Un metered air either from a leaky servo and or vac pipes.

 

[paul_jw]

Big thanks for all your replies.

Ill replace the pipe to the carb today. I realise taking them off and on isnt great but i need to find why this car isnt running right.

Im going to take the diaphragm off later and see if thats the problem.

Should i just look at the air hoses that come from and to the carb for leaks? or just anything coming off the inlet manifold that holds air?