Desperate for advice! Car stalls when braking, but not in reverse

Fingers crossed that's it mate!  

did it fix the issue?

jaaquo said

did it fix the issue?

Sadly, it doesnt appear so.

The mechanic I took it to replaced the lifter pumps worn rubber O rings and I took it for a quick drive. I tried stopping again and the engine still cut out.

Then barely a few secounds in I noticed smoke from under the bonnet. Busted fuel line spraying fuel everywhere.

Its not a fuel line that goes to the injectors, its one of the metal braided ones that goes to a device at the front of the engine - Im not sure what it is.

So that *could* be the issue, but it only started leaking seriously now. I know I'm clutching at straws but it could have been a loss of pressure in this line that some how does it. Or even fuel dripping on a connector.

I also have a new theory: Since getting the car I have not actually replaced the battery with a proper battery thats meant for that car. Both the mechanic and I have used generic batteries from other cars. It might be worth getting the proper battery in.

Again clutching at straws, but this really has be dumbfounded!

That could be your WUR mate at front off engine for the fuel lines 

Swerve said

That could be your WUR mate at front off engine for the fuel lines 

Yeah Im pretty sure it is.

Would you know if the WUR could be causing my issue (the engine cutting out for no reason)? As I said I'm running out of ideas    

Hi mate
Well it might not be helping but to be honest I'm not to hot on stuff like this, I'm sure rubjonny or mark1gls  who have already commented will give you some more pointers, hope you get it sorted soon mate 👍

my first thought would be no, as i would assume any leak that was enough to affect it would have been obvious with fuel seepage/smell. but you never know, you do at least have a definite problem that you can fix so thats some good news at least

rubjonny could it be a problem with the pressure in the fuel system when he is stopping ? And the WUR connection finally gave up with pressure caused?

yeah for sure, but my thoughts were if it was a loss of pressure to the wur you would have seen leakage/smell of fuel?  may have only been a small amount so not really noticeable like…

If the rubber seal at the pumps were at fault, I would have thought it would have a permanent effect making the car die when trying to drive it under any load, rather than just under braking, so not surprised that it didn't fix the issue.

The WUR normally causes issues at cold running if it isn't functioning properly, IE; not opening up to add additional fuel.
Once the block is warmed up, the WUR shuts off and this circuit is out of the equation so-to-speak.

I am guessing you have this issue when the engine is both cold and warm after being allowed to idle for a longish period of time?

As long as the battery is good (not old and dry/knackered), then as long as it has enough power to crank and start the car, I can't see this being the cause either.

I am starting to think that this a practical joke - the seller of the car has rigged up some dodgy wiring earthing out a live feed somewhere if the brake is pressed, though even this would be difficult to do on purpose for it only to happen when traveling forwards!

the wur is always part of the equation on kjet, it constantly sets the control pressure in the metering head as it is heated up by the engine block and the wee electric heater inside. even when fully warm it is still responsible for keeping the control pressure set correctly

so if pressure to the wur was lost from a leak this could well explain it, I just woudl assume that a smell of petrol would have been noticed as well as evidence of a leak as we're talking 3-3.5bar of pressure on the output side and 5bar on the input side

rubjonny said

 I just woudl assume that a smell of petrol would have been noticed as well as evidence of a leak as we're talking 3-3.5bar of pressure on the output side and 5bar on the input side

To be honest I think could have missed the leak if it was small enough. The leak is underneath the air intake piping between the air box and the throttle body and engine bay hasnt been cleaned in ages so grease and oil smell everywhere.

Also, I guess I havent really tried testing the car when the engine was properly warmed up. It was always fiddle with something, start, test, nope! fiddle with something, start, test, nope! etc.

Haha look at me hoping against hope that replacing this fuel line will solve all my problems!

Its not a test I've ever tried but does anyone know how long the engine would carry on running for if you just killed the fuel pump?
Or in other words would the engine die as soon as power to fuel pump is switched off or would residual pressure in the lines/accumulator keep it running for a few seconds? Obviously dependant on load but say if it were just idling?

It seems odd that if it were fuel related it dies so quickly.

Does it re start straight away on all four cylinders or does it splutter back into life. If it fires straight away on all four then its not fuel related and I would say its a wiring fault somewhere on the ignition side or earths. I've even known a loose distributor not being well earthed to give similar issue.

 If it splutters into life when restarting up then I would say its fuel related.

Well I think I can answer that question Yomp ,
 
First of all mines a 1990 with fuel injection.
The alarm system is rigged up to cut the power to the fuel pump and not the battery.
So if I disarm the alarm and get in the car, the system will re-arm itself again if I don't put the key in the ignition within ten seconds.
If I now put the key in and start the engine (without disarming it again) the engine will start instantly but run for 3 seconds and stop dead. (the car is stationary of course and not under load)

So with that all that in mind, I'd say that with the car in motion (unlike above) it would feel almost instant to the driver because the engine is under load and using that spare fuel faster!    

I'm no electrical expert.
But I don't suppose some Nutter has been messing with the electrics and wired in the brake lights to use the same power feed that the fuel pump uses? Therefore starving the pump of power the instant the brakes are applied. Or something similar!
A quick test would be start the car and whilst stationary apply the brakes and see what happens.  

Just a thought because this problem is getting really annoying now!  

golfcabrio

When you restart the car after the 3 second run does it splutter into life or fire up crisply? Although I guess if the main pump is priming upon "ignition on" then it would start cleanly.

3 seconds isn't long but under braking the engine isn't under load so I would say about the same time.

I'm just thinking out loud!!

Yomp said

golfcabrio

When you restart the car after the 3 second run does it splutter into life or fire up crisply? Although I guess if the main pump is priming upon "ignition on" then it would start cleanly.

3 seconds isn't long but under braking the engine isn't under load so I would say about the same time.

I'm just thinking out loud!!

Yomp
When I press the button to dis-arm the alarm it's starts instantly, no hesitation!  
It's Milliseconds.  

Hi all,

I know I've said this before but I think this time I've got it!

I replaced the fuel lifter pump and did a test run and it was fine. Unfortunatly the car isnt registered yet so I cant do a proper run.

I hope I'm not jumping the gun but I guess the issue had something to do with fuel pressure, or lack there of.

Or maybe the faulty old pump was causing some sort of electrical shortage as well (the fuel pump fuse blew early on when I was testing)?

Anyway, many thanks again to all those who commented! Fingers crossed!

Fingers crossed!