mx5 fuel pipes

[RichardH]

can anyone tell me how to pipe up the fuel pipes please. im using a mk2 1.8 mx5 i forgot to take a drawing of the pipes, i have the standard mx5 sender/pump fitted in my tank. do i need two pipes to the front or one?

[garyt]

hi mine is a 2003 1.8 and if you look on my build you can see mine but here is a description.
The fuel system is pressurized , so 1 fuel line rear to front then flexi to the fuel rail in (its behind the throttle body and TPS wiring, points down wards )
right, from the tank sender unit, you have 2 pipes, 1 goes into the fuel filter (suitably mounted) the fuel filter outlet goes to a T piece, one side of the T goes to the main fuel line, the other leg of the T goes back to the sender unit (return).
Thus the whole system is pressurized and on start up when you turn the key the in tank pump pressurises the system and then cuts out until the fuel is required by the injectors/ ecu/ etc.
I put a plate on top of the chassis rails (o/s rear lower corner) and mounted my filter there.
if you need any help or clearer pictures I can get some tomorrow . also I would need to check which pipe is which on the sender top as I cant remember of the top of my head.

[Ianr]

Slightly different from mine which is a 1.6 Mk 2 based car so I will describe it just in case its similar to yours. Two pipes come out of the standard fuel pump/sender unit at the tank. One is a pressurised feed pipe and the other is a return. BOTH go to the fuel rail at the front of the car with one attaching to the inlet and one the return of the rail via a short flexi pipe. I did all mine in 8mm copper from the tank to the front of the car using some clips I have which take two 8mm pipes and one 5mm brake pipe. Cost about 40p each but I had to buy 100 :-)

[garyt]

before doing anything check your fuel rail and see if you have 1 inlet or 1 and a return as Ian said there are some differences between marks and models

[RichardH]

thanks guys i will look today and let you know, im sure mine was one pipe with various gubbins on the front inner wing, i can remember putting a grinder through the floor and fuel pipe when i cut up the donor and shitting myself !

[garyt]

haha grinder = sparks + petrol......... glad your still with us !!!

[RichardH]

so i have 2 8mm pipes that go up under the manifold at the front of the engine, looks like one is fuel rail and the other goes to a small round device that has a small pipe out the other end, im sure that went to the canister on the wing

[RichardH]

haha just remembered i have a photo of the car in half, this just confuses things more it shows three pipes so i guess mine needs ttwo pipes and the third must be a breather from the canister on the inner wing.

[garyt]

right did some searching through the piles o stuff I have on the mx5 and derivatives;
firstly;
" some have fuel return and these have regulator on end of fuel rail with a vac feed to inlet manifold which raises and loweres fuel pressure according to engine vac/pressue etc, this is system fitted to my jdm 1998 mk2 1.8, but apparently some other mk2 and mk2.5 have a returnless fuel system and on these fuel reg is in the tank and fuel pressure is static."

and secondly I think this is what you have as in diagram,

therefore pipe from fuel rail = fuel in, pipe from fuel pressure regulater (round thing) = RETURN line, smaller pipe from FPR (round thing) vac from inlet manifold

this would indeed agree with 2 x 8mm pipes and a smaller vac pipe, and so if this is what you have then 2 fuel pipes required front to back
hope this helps, good luck

[RichardH]

thats the very thing gary cheers !