Jake Posted July 10, 2005 Share Posted July 10, 2005 I've just noticed a disconnected vacuum pipe on my dead VVTi engine. Could this have been the cause of the engine going bang? http://img73.imageshack.us/img73/3575/p10100052an.th.jpg Quote Link to comment Share on other sites More sharing options...
LeeT Posted July 10, 2005 Share Posted July 10, 2005 could well be jake. thats the vacuum source for your fuel pressure regulator Quote Link to comment Share on other sites More sharing options...
Alex Posted July 10, 2005 Share Posted July 10, 2005 Yeah...could well be...if it was only getting a atmospheric source it wouldn't have raised the pressure for boost. It would have driven fine off boost. Shit, that's a real pisser if it was the cause. Quick Q. Had you tinkered in that area that you can recall? Even cleaning it? Toyota don't clamp it so it should be able to come off of it's own accord....unless the FPR was blocked and caused the pipe to blow off. WTF is T'd off it? Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 10, 2005 Share Posted July 10, 2005 Argh, that could well be it On-boost you'd have lost a lot of fuelling... I saw a drop from 10.5:1 afrs to 12.5:1 by dialling the static pressure down 4psi - so dropping it by 14psi would be disasterous I'd imagine it blew off while you were driving along, as it's difficult to start the car with it missing. -Ian Quote Link to comment Share on other sites More sharing options...
Alex Posted July 10, 2005 Share Posted July 10, 2005 I'd imagine it blew off while you were driving along, as it's difficult to start the car with it missing. -Ian I thought mine started without it attached... VVTI - that pipe goes the Fuel Pressure Up VSV (the one I want to borrow Jake ) Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 10, 2005 Share Posted July 10, 2005 Well, I can't really count yours as an example of normal behaviour, can I? -Ian Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 10, 2005 Share Posted July 10, 2005 Could this have been the cause of the engine going bang? YES. Having been experimenting with the vacuum of this hose (FPR compensation) I can say that without it at 10psi you're looking at AFR 15:1, and that's on a UK model. If you were doing 1 bar or more, I'd bet it went into 18:1 and beyond, certain meltdown. Quote Link to comment Share on other sites More sharing options...
tbourner Posted July 10, 2005 Share Posted July 10, 2005 Bummer dude, I may go and put a cable tie round mine as I've just put new hoses on there!! Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 10, 2005 Share Posted July 10, 2005 There is an overlap of half an inch at least there, it can't really be blown off easily by itself. I guess it doesn't hurt to use an 8mm hoseclip just for extra peace of mind. Quote Link to comment Share on other sites More sharing options...
Pete Posted July 10, 2005 Share Posted July 10, 2005 I'm off to find some clips too I think! Quote Link to comment Share on other sites More sharing options...
paul mac Posted July 10, 2005 Share Posted July 10, 2005 i started mine up the other day to move it into the garage with the boost controller head unit disconected which is connected to the FPR (so essentialy the same scenario) and the car would barely idle and was rough as hell, if you lost this pipe i would think you would notice Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 10, 2005 Share Posted July 10, 2005 i started mine up the other day to move it into the garage with the boost controller head unit disconected which is connected to the FPR (so essentialy the same scenario) and the car would barely idle and was rough as hell, if you lost this pipe i would think you would notice Like I said, you'd notice if it was off when you tried to start the car. Driving it is a different matter, it'd run over-rich on cruise but would still *run*. On boost it'd lean off though :thumbdown -Ian Quote Link to comment Share on other sites More sharing options...
Jake Posted July 10, 2005 Author Share Posted July 10, 2005 Quick Q. Had you tinkered in that area that you can recall? Even cleaning it? Toyota don't clamp it so it should be able to come off of it's own accord....unless the FPR was blocked and caused the pipe to blow off. WTF is T'd off it? Nope, no tinkering at all in that area. WTF is T'd off it? The GReddy PRofec E-01 boost controller's vacuum pipe. How gutted am I? If only I'd taken a look under the bonnet when the car started misfiring. I honestly thought it was bad fuel :KicksHimself: Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 11, 2005 Share Posted July 11, 2005 Damn Jake that is a shame bud. Quote Link to comment Share on other sites More sharing options...
Pete Posted July 11, 2005 Share Posted July 11, 2005 I've just twigged. That's K55 BYE isn't it? I guess the only redeeming factor is how cheap you got the car for in the first place. You can build it back up stronger and be like new for a fair price in total. Quote Link to comment Share on other sites More sharing options...
Jake Posted July 11, 2005 Author Share Posted July 11, 2005 I've just twigged. That's K55 BYE isn't it? I guess the only redeeming factor is how cheap you got the car for in the first place. You can build it back up stronger and be like new for a fair price in total. Yeah that's the one mate. Doesn't look like I'm going to actually make money on this one now. Quote Link to comment Share on other sites More sharing options...
SkyJawa Posted July 11, 2005 Share Posted July 11, 2005 What a complete ar$e mate Gutted for ya............. Quote Link to comment Share on other sites More sharing options...
Guest Usmann A Posted July 11, 2005 Share Posted July 11, 2005 Sorry to hear this Jake. you reacon shell be back up and running for JAE/TOTB? Quote Link to comment Share on other sites More sharing options...
Jake Posted July 11, 2005 Author Share Posted July 11, 2005 Sorry to hear this Jake. you reacon shell be back up and running for JAE/TOTB? Nah mate, not this one. I've got a replacement lump to go in it but I can't afford to have it fitted at the moment. Unless I fit it myself it'll have to wait for a while. My grey car is fixed now though (broken cambelt tensioner bracket) so I won't be Supraless for TOTB. Quote Link to comment Share on other sites More sharing options...
Willson Posted July 11, 2005 Share Posted July 11, 2005 I'd have thought there was some sort of emergency 'limp' mode that would be activated if something like this happened. Apologies for the mechanical retard post. Just seems surprising that a small air pipe coming off would have such immediate, terrible consequences. Quote Link to comment Share on other sites More sharing options...
Guest a71ak Posted July 12, 2005 Share Posted July 12, 2005 I think there's a missunderstanding here guys ... I hope I'm not wrong because you got me confused since every one agreed to this .... Jake this can't be the reason for the engine to blow ... because the disconnection of this vacuum pipe will increase the fuel pressure not decrease it ... Toyota re not that dump . Fuel pressure regulator is spring loaded to a certain pressure from factory the only time they need to decrease this pressure is during idle to have better idle, fuel consumption, emission control etc ... so to achieve that they connected it to the intake manifold to sence vacuum ... and this vacuum will suck the spring/diaphram down a bit to decrease the FB ... and since the only time you have vaccum is when your throttle closed at idle ... so in normal driving conditions the regulator well have no vacuum acting on it and the pressure will be higher. Sorry for the dump explenation but Hope this help !! Ali Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 12, 2005 Share Posted July 12, 2005 ..Jake this can't be the reason for the engine to blow ... because the disconnection of this vacuum pipe will increase the fuel pressure not decrease it ... Toyota re not that dump . Fuel pressure regulator is spring loaded to a certain pressure from factory the only time they need to decrease this pressure is during idle to have better idle, fuel consumption, emission control etc ... so to achieve that they connected it to the intake manifold to sence vacuum ... and this vacuum will suck the spring/diaphram down a bit to decrease the FB ... and since the only time you have vaccum is when your throttle closed at idle ... so in normal driving conditions the regulator well have no vacuum acting on it and the pressure will be higher. Sorry for the dump explenation but Hope this help !! Ali Dude, if you want to explain something, don't you think you first need to understand it yourself? Quote Link to comment Share on other sites More sharing options...
merckx Posted July 12, 2005 Share Posted July 12, 2005 Dude, if you want to explain something, don't you think you first need to understand it yourself? That was a bit of an unnecessary insult, why did you think he didn't understand it himself ? Have I missed something? Quote Link to comment Share on other sites More sharing options...
JohnA Posted July 12, 2005 Share Posted July 12, 2005 Well the last thing you need in the 'tech' section is technical 'explanations' that are wrong or incomplete, presented as 'facts'. Disconnecting that pipe will make it run lean as hell under boost. Below is a supra setup with that hose effectively disconnected under boost (the one-way valve allows vacuum though) http://www.max-boost.co.uk/stuff/FPR_fishtank_valve.jpg Do you want to know the AFRs seen under boost? Brrrrr... Quote Link to comment Share on other sites More sharing options...
merckx Posted July 12, 2005 Share Posted July 12, 2005 Below is a supra setup with that hose effectively disconnected under boost (the one-way valve allows vacuum though) http://www.max-boost.co.uk/stuff/FPR_fishtank_valve.jpg Do you want to know the AFRs seen under boost? Brrrrr... Why have they chosen to do this ? Quote Link to comment Share on other sites More sharing options...
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