Solex 4A1 E12 520 Auto

[rh306]

..just wondered if there were any Solex 4A1 geniuses on here My newly painted E12 has a mysterious fault which I've not been able to get to the bottom of.

The car runs fine, virtually all the time. The problem occurs on long motorway journeys of about 140 miles. I take a break half way through the journey about 80 miles in, the problem starts without fail about 130 miles into the journey. Suddenly the accelerator stops responding and the car slows down to about 40mph (not ideal on a motorway ), you can just about keep momentum going with the accelerator floored but the power only comes intermittently. It eventually seems to recover, although I usually turn off onto a B road... Any ideas on this would be gratefully appreciated.. We've tried all the likely solutions, like new fuel filter, fuel pump is recent.. Carb icing was one idea... The way it happens at virtually the same time on each journies is puzzling though

Keen to make the sharknose meeting this year, this fault is kind of holding things back though

[Peter V.]

The problem only comes with driving 130 miles on the motorway ( constant speed and RPM then). If you drive the backroads with variable speed and rpm's then you have no problems?

[e21-Mark]

I hate Solex carbs. I'd bin it in favour of a Weber replacement.

Your e12 looks gorgeous.

[Jeroen]

Great that Peter already found your topic, he knows these carbs pretty well.

And my oh my what a beautiful E12! Hope you can make it to this year's Sharknose Meeting!

[rh306]

The problem only comes with driving 130 miles on the motorway ( constant speed and RPM then). If you drive the backroads with variable speed and rpm's then you have no problems?

..yep, it's only ever done it on long motorway journeys. Pootling around London and B roads in Herts is fine. Because of this issue though, it's being a bit underused and my 318ti seems to be getting more miles put on it than this one

Thanks for the comments chaps

[rh306]

I hate Solex carbs. I'd bin it in favour of a Weber replacement.

My mechanic is keen to keep the originality because the car is a low miler, one owner etc. I'm tempted by the Weber though, can always keep the Solex in a box, if anyone in the future ever want to put it back on

[e21-Mark]

Where abouts are you in London?

[Peter V.]

Just a simple thing maybe, Have you checked the vent of your fueltank.

When you ask a large amount of fuel for a long time it could be that your fueltank is going to create a vacuum.
With driving in town or backroads at various rpm,s and speed your fueldemand is not so high for a long time that you create it so much.

[rh306]

Just a simple thing maybe, Have you checked the vent of your fueltank.

When you ask a large amount of fuel for a long time it could be that your fueltank is going to create a vacuum.
With driving in town or backroads at various rpm,s and speed your fueldemand is not so high for a long time that you create it so much.

...ah I hadn't thought of that, I'll have a look, thanks

[rh306]

Where abouts are you in London?

you have PM

[jimbob]

My friend had this kind of thing with a jaguar.
A leaf inside his fuel tank would stop the flow of fuel
Then when the pressure dropped after he left it for a
While the leaf would move and all would be o.k.
Took him ages to find out what it was

[Peter V.]

Just a simple thing maybe, Have you checked the vent of your fueltank.

When you ask a large amount of fuel for a long time it could be that your fueltank is going to create a vacuum.
With driving in town or backroads at various rpm,s and speed your fueldemand is not so high for a long time that you create it so much.

...ah I hadn't thought of that, I'll have a look, thanks

Whenyou are driving he car for a while you must remove he fuelcap andere listen if you her the airflow then.