Alex Posted May 30, 2002 Share Posted May 30, 2002 I know its a wussy pile o' poo but could it flow enough for 8 440cc injectors? Whilst running at WOT at about 1.3bar+ on stock j-specs I doubt it, but when have I shyed away from wringing every last drop of performance out of my car! Quote Link to comment Share on other sites More sharing options...
Adam W Posted May 31, 2002 Share Posted May 31, 2002 Arrrrggghhhhhh! Alex! Do it properly! I'm picking my new fuel pump up from Chris next week - guaranteed 600bhp, very reasonable price. Quote Link to comment Share on other sites More sharing options...
Gareth Davies Posted May 31, 2002 Share Posted May 31, 2002 Alex, your car will end up with and engine build one way or another... so don't worry about it I think the cheap lame way to do it is with an FSE valve, they're pretty cheap really - and if you don't mind a both rather than a fix a good way to go. I think the equations for working out pump capacity are pretty simple, and i've seen them posted here before. Might be worth a search? I think the stock j-specs really aren't good for over 1.2. Quote Link to comment Share on other sites More sharing options...
GavinL Posted May 31, 2002 Share Posted May 31, 2002 Originally posted by Gareth Davies I think the cheap lame way to do it is with an FSE valve, they're pretty cheap really - and if you don't mind a both rather than a fix a good way to go. I think the equations for working out pump capacity are pretty simple, and i've seen them posted here before. Might be worth a search? I think the stock j-specs really aren't good for over 1.2. My understanding is that s FSE valve increases fuel line pressure and therefore forces more fuel thorough the injectors. I don't think that an FSE would help run more injectors if the pump is close too being maxed out. The TDI web site has the pump output chart as I recall. Quote Link to comment Share on other sites More sharing options...
Gareth Davies Posted May 31, 2002 Share Posted May 31, 2002 Ha ha, i'll learn this all eventually... one mistake at a time. Just thought of it regards to IanC's mod level. Since his turbos are considerably more powerful and they ran at a highish boost on the stock system, it's destruction probably being related to the FSE valve... So by GD logic that ment Stock+FSE = plenty of botched power. I think i'd take a TDI chart with a grain of salt. I just can't remember where the earliest point of failure is, the pump or the injectors. Quote Link to comment Share on other sites More sharing options...
Adam W Posted May 31, 2002 Share Posted May 31, 2002 The pump will be rated at gallons per hour (gph) at a certain pressure. Increasing the fuel line pressure will mean more fuel is squirted through the injectors as they open, but if the pump can't supply that volume of fuel at that pressure you'll still lean out. Work out how many gph you need to attain your horsepower goal, work out what line pressure you will need to squirt that much through your chosen injector setup at 75-85% duty cycle, and then choose a pump that will flow that much fuel at that much pressure. Calcs are available on the RC engineering website, but remember they will be talking about american horses so leave yourself some headroom. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted May 31, 2002 Share Posted May 31, 2002 With a fuel pressure gauge I could actually see the pressure drop of with an FSE, 2 additionals & 6 x 430cc's with a J spec pump. Pay the money. Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 31, 2002 Share Posted May 31, 2002 Agreed. Show us the money! Show us the money! Not sure how you were using me as an example, GD I think the earliest point of failure was the tuning company... No, but seriously folks, some people have used FSE valves on stock j-spec injectors and pumps (i.e. RC Developments) - make your own minds up on the success of that. Others have uprated the fuel pump, some done the FSE valve *and* fuel pump. Me, I'll go for the injectors and pump - no botch factor! Providing you get a brand new pump that works!!! Gngngngng. -Ian PS I heard that too much line pressure can lock the injectors open. Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted May 31, 2002 Share Posted May 31, 2002 Originally posted by Ian C PS I heard that too much line pressure can lock the injectors open. Or closed. Quote Link to comment Share on other sites More sharing options...
paulrenn Posted June 2, 2002 Share Posted June 2, 2002 Guys, How easy/difficult is it to access the injectors and pump for replacement? What do you have to remove from the engine to reach them (if anything)? Anyone know what type of injectors (top feed, side feed, size) are needed, and ditto with the fuel pump? Paul Quote Link to comment Share on other sites More sharing options...
GavinL Posted June 2, 2002 Share Posted June 2, 2002 Originally posted by paulrenn Guys, How easy/difficult is it to access the injectors and pump for replacement? What do you have to remove from the engine to reach them (if anything)? Anyone know what type of injectors (top feed, side feed, size) are needed, and ditto with the fuel pump? Paul are you talking uk spec or j-spec? Quote Link to comment Share on other sites More sharing options...
paulrenn Posted June 2, 2002 Share Posted June 2, 2002 For removal, aren't they both in the same location? For sake of argument, let's talk jspec... Quote Link to comment Share on other sites More sharing options...
GavinL Posted June 2, 2002 Share Posted June 2, 2002 Originally posted by paulrenn For removal, aren't they both in the same location? For sake of argument, let's talk jspec... I understood by reference too pump and injectors only you were referring to 440cc to 550cc conversion of the j-spec. Are we talking about general fuel system upgrades which would include the fuel rail and regulator etc Quote Link to comment Share on other sites More sharing options...
paulrenn Posted June 2, 2002 Share Posted June 2, 2002 I just wanna know, how difficult it is to remove the stock ones. Why would I want to change the fuel rail? Does the stock design cause some cylinders to run lean? Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted June 2, 2002 Share Posted June 2, 2002 Stock injectors are side feed, most aftermarket injectors seem to be end feed which necessitates changing the fuel rail. I'm pretty sure you have to remove the intake to get at the injectors. To access the fuel pump; remove your spare wheel (errrr well space saver) undo the cover plate and you will find access to the top of the petrol tank. You will find a plate bolted to the top of the petrol tank with the pipes and wires going through it to the in-tank fuel pump. Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 5, 2002 Share Posted June 5, 2002 Access to the injectors requires removal of the top part of the intake manifold. It took me about 3-4 hours to swap injectors from j-spec to uk spec. I have pictures of every stage but I haven't uploaded them or written up the install yet. The fuel pump is under the metal plate in the boot, as Martin describes. What he doesn't mention is the plastic screw-threaded ring that holds it all in place and is a b@stard to remove! You'll know what I mean when you get to it... -Ian Quote Link to comment Share on other sites More sharing options...
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