Why does my car still run when i clamp the return?

1. Princey_vts Regular Poster Joined: Jan 2008 Lichfield Posts: 378 MK2 VTS, MK2 VTR

   #1 26th June 2010, 14:36

   Seriously, thought my fuel pump had gone this week. Car not running. Just starts and then cuts out. Well now, iv clamped the return pipe that connects to teh fuel pump and the damn thing runs as sweet as a nut? Would a new fuel pump sort this or can i run it like this long term?
   
   I dont see the point in having a return on the fuel pump now? What is its use?
   
   Cheers
2. Saxo-Guy Regular Poster Joined: Dec 2009 Posts: 477

   #2 26th June 2010, 17:02

   Im not really into all this but my guess would be that if there is a valve that monitors the presure in the fuel rail and this is broken so there wont be enought pressure for the injectors to squirt the right amount of petrol into the engine, which i assume is why it cuts out. Therefore when you block the pipe your allowing the fuel rail to build up its pressure without it escaping through the valve if there is one. So my guess is that is why it runs when you clamp the return. I might be completely wrong though !!
3. Princey_vts Regular Poster Joined: Jan 2008 Lichfield Posts: 378 MK2 VTS, MK2 VTR

   #3 26th June 2010, 17:56

   Quote:

   Originally Posted by Saxo-Guy Im not really into all this but my guess would be that if there is a valve that monitors the presure in the fuel rail and this is broken so there wont be enought pressure for the injectors to squirt the right amount of petrol into the engine, which i assume is why it cuts out. Therefore when you block the pipe your allowing the fuel rail to build up its pressure without it escaping through the valve if there is one. So my guess is that is why it runs when you clamp the return. I might be completely wrong though !!

   funnily enough, my old mans the mechanic and he says the same. Nice one buddy. Just need to get the name of that valve now. I know which one it is. Cheers
4. Saxo-Guy Regular Poster Joined: Dec 2009 Posts: 477

   #4 26th June 2010, 19:03

   ha Thats good news then ! Maybe get a pic up so someone can tell you on here ? Glad i could help
5. lisavts Infrequent Poster Joined: Mar 2004 Stocksbridge, Sheffield Posts: 182 Mercury Grey VTS 1998

   #5 26th June 2010, 19:15

   
6. lisavts Infrequent Poster Joined: Mar 2004 Stocksbridge, Sheffield Posts: 182 Mercury Grey VTS 1998

   #6 26th June 2010, 19:22

   
7. lisavts Infrequent Poster Joined: Mar 2004 Stocksbridge, Sheffield Posts: 182 Mercury Grey VTS 1998

   #7 26th June 2010, 19:24

   09
   
   1985 32
   
   PRESS REGULATOR
   
   is this what you folks mean
8. Princey_vts Regular Poster Joined: Jan 2008 Lichfield Posts: 378 MK2 VTS, MK2 VTR

   #8 27th June 2010, 13:48

   i believe so, its like a metal circle thing on the right of engine bay just underneath the throttle body. Think thats the one. Im not mechanical savvy so just going on what people are saying. Im driving in it today with my back seats out and a clamp on the return. its still moving. lol