clubstylus

Im unsure if you can recall but last summer I had trouble with the engine cuting out after it had run for about 10 minutes, ie half a lap. When the engine cooled down the car would run again for 10mins.
It turned out to be the fuel pump was siezing up when it got hot. I fitted a new pump for the Llandow day (the management had not been adjusted for the new fuel pressure). Well that was the last time I used the car. It has been away waiting for the new garage. The car is back in its new garage, started it up & the usual spring check over, and the pumps gone the same way!.

The pump sits in a small swirl pot (VW) in the engine bay on the bulkhead under the pedal box. So not the hot side. I know the fuel keeps the pump cool & is constantly circulating. It has not run dry.

Any ideas as to why or how to overcome the problem, otherwise its a new pump every few drives!.

Hope you enjoy your easter eggs.

You are using a low pressure pump to feed this from the tank?

Yes. I have a small feeder pump.

Kevin , try a PM to ''babybertha'' on this members list . He's a good engineer and if you give him all the info on past history (pipe size/pump psi/filter/layout) I'm sure he'll come up with an answer we all haven't thought of

Do you have a photo of the accumulator in place?

I had the same problem and had the swirl pot in the same place as you.
Fixed it by insulating the swirl pot with aluminium/glass fibre type material.
Nevr had a problem since.....

Hi. Thanks for the comments so far.

Possible causes are;
Heat - insulate the swirl pot. I am unsure that this will help much. The pump is in the shade and the fuel is running around the injectors & back to the tank. This should keep the pump cool. Also the problem happens almost exactly after 10minutes, the engine has only just got to temp & the fuel temp would not have risen that much.

Pressure - perhaps the regulator is set to high & the pump is forcing against it. The injection timing is set at 2.05 m seconds on idle. This does seem to be a short duration looking at other maps suggesting a high pressure.

Incorrect plumbing - It’s a VW accumulator. From the pump the high pressure returns to the top of the swirl pot next to the pump. The low pressure feed enters the rear chamber & the return to the tank also runs from a rear connection.

Over voltage - I feel this is unlikely as the battery only ever gets up to a max of 13Volts. Also this would shop up as a blown fuse or melted pump.

Rob I will pm BB, Thanks

An Update.

Today I have an expert (well it cost a lot so he must be) look at it.

The fuel regulator was all over the place, but mainly off the scale. So the pump was working at over 100psi (should be 40-45psi). 1 injector does not seem to be working correctly & the throttle linkage is not smooth at idle. He checked the ignition & cam timming - this was OK.
We tried a regulator from another car (Porsche 911) but the pressure was still 60psi. Its possible the injectors I have cannot run at that pressure & are having trouble closing.

I need to get the injectors flow tested & sort the regulator out. Then its back for another go.