I\'ve been having a fuelling issue with my RX7 since it\'s rebuild.
I\'ve checked everything that I can think of without stipping it back down to the injectors...
This reminded me, that when I was doing the rebuild there was an anomaly with the secondary fuel rail that I never did work out and I think I may have just put it how I thought just to get going...
Anyway, attached is a picture of the fuel rail (actually it\'s my spare fuel rail that I dug out for this pic), could someone that knows please make sure that I\'ve labelled it correctly. It\'s mainly the vac hose situation that I\'m confused about...
1 is obviously the fuel input (coming from the primary rail)
2 and 3 are obviously the injector holes
4 seems to be the fuel return hose
5 and 6 both appear to be vac nipples, but all the diagrams I could find only showed 1 vac nipple... so not really sure what to do with them, can\'t remember what I ended up doing in the engine bay either......
Thanks in advance and sorry for all the recent questioning
Looks correct to me.
Is that from a uk car?
I\'d certainly say that the end most vac line is the one that will correctly regulate fuel pressure.
On these rails with 2, I am not sure what the 2nd nipple is for.
Yes, it\'s a UK spec car... and I have 2 identical fuel rails.
I\'m not really sure what the lines are for either... I think they\'re both connected to vac (where the old tubes seemed to want to flex to) But I really don\'t see how having a vac tube on both sides is going to help anything... I would have though it would make it worse....
Maybe it\'s time for some aftermarket rails?
It\'s just possible that the UK car\'s had this extra nipple to work with the PRC valve - basically it cut\'s the vacuum to the fuel rail (raising the pressure at idle) when the engine is started warm, to prevent or reduce percolation of the fuel.
I have an S4 secondary rail on mine, it was modified to take aftermarket fuel components. The FPR part was removed - so I have an outboard one. I did check my old S5 one, and that had both nipples too. The PDF I have for the car is for the US model, and it only shows one vacuum nipple.
Do you think I could get away with only having the end most one attached? Because that\'ll probably be better for the car than having them both connected to standard vac fittings
I probably will get an aftermarket fuel rail and external FPR when I have a bit more money... I\'m also going to do a rats nest removal at some point, but I\'d like the car working properly 1st so that I know any problems haven\'t been caused by me fiddling.