Supra ST Myster Posted January 6, 2004 Share Posted January 6, 2004 Is it ok to do the 12V relay mod that i have made on a standard J-spec Fuel pump?? been asked the question. Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 6, 2004 Share Posted January 6, 2004 No, it can cause idle issues and serves no useful purpose whatsoever, anyway. Link to comment Share on other sites More sharing options...
Guest Terry S Posted January 6, 2004 Share Posted January 6, 2004 I agree with Chris. I can see no reason to do the mod as the JDM cars switch to 12v as soon as positive boost is made anyway. Now if you could switch it from 9v to a constant 14v, that would make a difference..... Pete Link to comment Share on other sites More sharing options...
Branners Posted January 6, 2004 Share Posted January 6, 2004 Didnt realise that, so are the UK specs different in that they only switch to 12v at a certain RPM? JB Link to comment Share on other sites More sharing options...
Guest Terry S Posted January 6, 2004 Share Posted January 6, 2004 They seem to be. It really needs someone with a fuel pressure gauge on a UK car to check. On mine ( J Spec) prior to all the work, you could visibly see on the gauge the jump as soon as the car made positive boost. I think Chris confirmed this some time back. Link to comment Share on other sites More sharing options...
Supra ST Myster Posted January 6, 2004 Author Share Posted January 6, 2004 thanks for the info, i didnt realsie that there was a difference between the U.K spec and the Jspec apart from the size of the pumps..?? So is it a waste of time then to do the mod on a Jspec when you have a walbro fitted or is that not the case?? Link to comment Share on other sites More sharing options...
Guest Terry S Posted January 7, 2004 Share Posted January 7, 2004 Yes. The walbro also flows more fuel than the Denso's at low voltage. Link to comment Share on other sites More sharing options...
GavinL Posted January 7, 2004 Share Posted January 7, 2004 Originally posted by Terry S They seem to be. It really needs someone with a fuel pressure gauge on a UK car to check. On mine ( J Spec) prior to all the work, you could visibly see on the gauge the jump as soon as the car made positive boost. I think Chris confirmed this some time back. I have a gauge fitted and I believe that I am still 9v/12v. I'm assuming my Walbro and FSE will not give the same result as the stock regulator? Link to comment Share on other sites More sharing options...
Steve W Posted January 8, 2004 Share Posted January 8, 2004 Terry, I was told that the Walbro doesn't "like" running at 9v ?? ALL TDi Walbros come with the 12v/12v relay kit as standard, and give the "they-don't-like-it" reason....... ?? I thought the idea was, if you've De-Catted etc the 12v mod allows slightly (miniscule?) better pick-up by being on-the-ball BEFORE positive boost ??? [i DUNNO......... bleet.... bah:blink: ] FatS. Link to comment Share on other sites More sharing options...
Supra ST Myster Posted January 8, 2004 Author Share Posted January 8, 2004 thats exactly what i thought as well??? Link to comment Share on other sites More sharing options...
dude Posted January 8, 2004 Share Posted January 8, 2004 I would say the reason to do the 12v conversion is more safety as you are relying on a box of tricks to switch you to 12v , its a mini ECU and as such i suppose could malfunction and leave you boosting like mad with a fuel pump not running at full efficiency !! Dude:flame Dev Link to comment Share on other sites More sharing options...
Steve W Posted January 8, 2004 Share Posted January 8, 2004 " BOOSTING LIKE MAD ! " THAT'S IT ! ! new t-shirt slogan in the makin' Dude-me-boyo ! ! Link to comment Share on other sites More sharing options...
Guest Terry S Posted January 9, 2004 Share Posted January 9, 2004 I think the 12v mod has come from the US. I also suspect the JDM car behave different. I will see if the walbro chart shows 9v and get back to you. Link to comment Share on other sites More sharing options...
Guest Usmann A Posted January 9, 2004 Share Posted January 9, 2004 Also, when doing the 12V mod, does the fuel pump ecu have to go? As, Thier is no FP ecu in my dads car, and hes had the 12V mod done? But, surely by having the fuel pump on constant when the ignition is one, there is a danger factor to take into account aswell, what if one has an accident? U Link to comment Share on other sites More sharing options...
Guest Terry S Posted January 9, 2004 Share Posted January 9, 2004 Right the only charts I have start at 12v, so they may not like 9v. If that's the case, to me it's all the more reason to insist on a UK pump. Part #'s Denso 195130-1020 or Toyota 23221-46110 Link to comment Share on other sites More sharing options...
Supra ST Myster Posted January 9, 2004 Author Share Posted January 9, 2004 But what difference would that make having a U.K pump on a jap spec as when driving normally the voltages are around 8-9V ?? Link to comment Share on other sites More sharing options...
Guest Terry S Posted January 9, 2004 Share Posted January 9, 2004 The UK pump flows much more fuel than the JDM. What are you actually trying to achieve with the car? Link to comment Share on other sites More sharing options...
Dragonball Posted January 9, 2004 Share Posted January 9, 2004 Originally posted by Steve W Terry, I was told that the Walbro doesn't "like" running at 9v ?? ALL TDi Walbros come with the 12v/12v relay kit as standard, and give the "they-don't-like-it" reason....... ?? I thought the idea was, if you've De-Catted etc the 12v mod allows slightly (miniscule?) better pick-up by being on-the-ball BEFORE positive boost ??? Spoke to Walbro people today - who basically haven't taken the 341 down to 9V 'For every one volt drop you get a corresponding 20% decrease in pump effeciency' This suggest that you should run the 12 volt mod with a relay with a walbro BTW - we sell both - Walbro and Relay! Link to comment Share on other sites More sharing options...
GavinL Posted January 9, 2004 Share Posted January 9, 2004 Originally posted by Paul E Spoke to Walbro people today - who basically haven't taken the 341 down to 9V 'For every one volt drop you get a corresponding 20% decrease in pump effeciency' This suggest that you should run the 12 volt mod with a relay with a walbro BTW - we sell both - Walbro and Relay! My Walbro runs fine in 9v/12v mode and you don't get to listen to the whining noise. Link to comment Share on other sites More sharing options...
Matt Harwood Posted January 9, 2004 Share Posted January 9, 2004 Originally posted by Paul E 'For every one volt drop you get a corresponding 20% decrease in pump effeciency' I thought this was whole the reason why Toyota actually did the variable voltage in the first place. When the car's not being pushed, the pump doesn't need to be flowing anywhere near as much fuel as at WOT... Hopefully increasing the life of the pump ect. Link to comment Share on other sites More sharing options...
dude Posted January 9, 2004 Share Posted January 9, 2004 Originally posted by GavinL My Walbro runs fine in 9v/12v mode and you don't get to listen to the whining noise. I converted back to 9v/12v to try and isolate a problem and was advised by a well known tuner to change it back to 12v asap , good enough for me , BTW the whinning noise is cool , normally the only whinning i hear is the uk owners saying they cant keep up !!!! Dude:flame Dev Link to comment Share on other sites More sharing options...
dude Posted January 9, 2004 Share Posted January 9, 2004 Originally posted by Usmann A Also, when doing the 12V mod, does the fuel pump ecu have to go? As, Thier is no FP ecu in my dads car, and hes had the 12V mod done? But, surely by having the fuel pump on constant when the ignition is one, there is a danger factor to take into account aswell, what if one has an accident? U Thats what the relay mod is for , contact Matt H and he will sort you out and be nice to you !!!!! Dude Link to comment Share on other sites More sharing options...
veilsideTT Posted January 9, 2004 Share Posted January 9, 2004 naaa, That'll be the UK owners Turbos Whinning as they blow past ya! :p :p Link to comment Share on other sites More sharing options...
dude Posted January 9, 2004 Share Posted January 9, 2004 Originally posted by veilsideTT naaa, That'll be the UK owners Turbos Whinning as they blow past ya! :p :p Not so far !!!!!! Wouldnt like a little wager on that would you ???? Dude:flame Dev Link to comment Share on other sites More sharing options...
veilsideTT Posted January 9, 2004 Share Posted January 9, 2004 ha ha! Ye Got Me! I'll pass on that one dude, I know whats under the Hood! Link to comment Share on other sites More sharing options...
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