Stalls when in long fast corners like entry to highways

[Dimi 7 1 Cars]

Hi All,, on the weekend I went for a 60km drive to check if the car will stall randomly, after Damir helped with pointing to the dual outputs relay for the fuel pump and I installed the new one.

It seems that this resolved the random stalls due to the pump stopping working. However...., On long sweeping corners when I keep a good speed (entry onto a highway type), after the half of the turn the gas pedal becomes unresponsive and two seconds later the dashboard lights up, indicating stalled engine. I put it in neutral, ignition Off and On, the car starts, into gear and off I continue.

What is this? This existed before the random stalls one day at stop lights or just cruising at low speed (the car did not want to start) that the new relay took care of apparently.

I figured, all of you are doing spirited driving on track or otherwise, so this must have happened on long sweeping corners. I read on this forum of random stalls but seems like there is no known culprit. Please give some suggestions, so I test. My next test will be lowering the speed in the corner to "grandma" level and see if it stalls then. It feels to me now that the centrifugal force in the long turn is depriving something of fuel flow. I had a half full tank. I will do tests with a full tank too.

Cheers!

[welshpug 1,661]

Its fuel surge, it seems to vary massively, there is no real pattern to it with regards to phase of the car, pre and post 90 have different fuel pumps but I have seen it happen with both.

[Anthony 1,003]

As Mei says, fuel starvation seem the most obvious culprit here, particularly if the tank was comparatively low on fuel at the time and it was a right-hand turn (position of the pickup toward the left of the tank means that starvation is much more prevalent on turning right than it is turning left).

 

Only thing that I would say is that fuel starvation should behave like you'd just taken your foot off the accelerator - the car would slowly lose speed, but assuming that it's a manual gearbox ("stick" on your side of the pond) car you've got, with it in-gear and the clutch pedal not depressed, the engine should keep rotating through the wheels turning gearbox (meaning the tacho keeps reading) and there shouldn't be any lights on the dashboard.  Fuel starvation should clear itself as you straighten out at the end of the turn or slow sufficiently to reduce the forces moving fuel away from the tank pickup - you shouldn't need to switch off the ignition and restart the engine.

 

I have seen similar behaviour before with a broken wire in the engine loom - forces from a sharp turn moved the loom enough to break the connection and kill the engine.  Stop the car, and the loom moved back to the original position, the broken wire would make contact again and the engine would restart.  Easy enough to replicate with the engine running and bonnet up, as wiggling the affected area of the loom would cause it to stall.

[Dimi 7 1 Cars]

I appreciate your replies, Welshpug and Anthony. Will try to replicate in different scenarios and long left turn too and post again. I am away till the 8th, so it will take some time to put my hands on it. 

[soundguy 13]

Take the fuel pump + housing out of the tank, have a good look inside the tank for an old fuel pump filter that might have come off over the years - it might end up getting stuck under the pump inlet when you're hitting certain cornering forces..

[Dimi 7 1 Cars]

Wanted to update you all that apparently the stalling in long sweeping corners is due to fuel starvation. I will keep testing, but for now I can confirm that if I have 3/4 full tank the engine did not stall on the long right sweeper.

This is what happened beforehand. I took the fuel pump out again to look inside the tank when the fuel was very low and all was good. However, after starting the car and going a few meters uphill, it died. Then restarted fine and idled at a traffic light on level ground, only to die again 50m into a slight hill, then restarted fine and by that time I knew I had to go back as now I had only downhill in case of a stall again. So, took my daily to the gas station and filled a can of 25L and refilled the 205. Now, I will be taking notes on the amount of fuel indicator if and when it stalls again.

Enjoy to Sunday!

[PhilNW 44]

What are the fuel pressures like when stood still, at idle and being revved?

 

Is anything stuck in the pump inlet behind the filter?

 

If i remember right there is a small circular sump/depression in the tank base just below where the pump sits to allow the pump to get the lowest bit of fuel out of the tank. Is that damaged obstructing the pump? How close is the pump to that sump? should be a few millimeters at most.

Edited October 18, 2023 by PhilNW