EU-spec NB1 BP-4W Fuel pressure question
 

Hi guys, I know I am fortunate enough to have return-style fuel delivery but I got a Q
The vac-source for the FPR runs to a small solenoid? up to the left side close to the small valve to the coal canister, and then goes to the manifold.
Wth?

The only reason i'd figure is.
By cutting the vac source to the FPR it could manage the fuel and therefore AFR's "some more" than just controlling the injectors?

You see, this little electrical thing got me messed up.
Maybe Im on the wrong continent asking questions about EU-spec but I have learned almost everything I know thru mt.net and Im knee deep in my turbo build atm

For further refrence, I will run a ms3 basic from mslabs

Doesn't sound right. Truthfully, I have asked multiple forums for a picture of the FPR vacuum source on an un-molested, Euro-spec NB1, with no success.

Still, what you describe makes no sense at all. I'm fairly certain that the connection is direct between the IM and the FPR.

Picture(s)?

I don't have any good pics.
This is a zommed in view.
http://i63.tinypic.com/2vi5qwi.png

You can see the FPR hose running along the ccanister hose and the electric thingy sits right behind.

Will take better pics on Saturday if I find the time.
Going away for a week

Thanks. It does look like that is what's happening, unless there are some connections behind the throttle spring that cannot be seen in this picture.

If, indeed, there is some valve between the IM and the FPR, I won't be able to help. Sorry.

Interested in the answer, though.

Well, I marked the small hoses from the module and they say fpr and VAC.
Will check if air just rushes thru or its acctuly a stop.
I probarly just run it fpr -> manifold

Think the ms will manage

Oh, if that is the question, I just ran a short line from the capped port right on the top of the IM directly to the FPR (I got a European FPR from England). The one that your hose is passing right by.

This one:
https://cimg7.ibsrv.net/gimg/www.mia...26193fe885.jpg

Works fine. Then you can use the cap to cap whatever port you no longer use.

However, If you would be so kind, when you return, please take a picture that shows where the hose connects to your manifold now. For science, I may try that location directly to the FPR and see if I can detect any difference.

I have removed my charcoal canister + the electrics for it.

Fpr still has vacuum line to whatever is under the metal bracket behind canister (under where the canister connects to)
And back to the im

IIRC the 94-97 USDM cars have a cold-start solenoid which limits vacuum to the FPR in order to raise fuel pressure on cold starts. That could be hidden behind everything on some EUDM 99+ return-style cars. You can safely delete everything between the FPR and the manifold when going to MS.

Aaaaand we have a winner!
That sounds about right. Thank you!

Thanks for all input everyone

@DNMakinson , I'm sorry but the motor is already out and vac hoses pulled.
I'd figure, vac source, vac source, same same (at least almost) But I want to recall that it was connected on the left side just behind the throttle body.
Will just mount it like you did, clean mount! Thanks for the replies!

Old pic from when I had a JDM98.
https://www.miataturbo.net/attachmen..._vs_99eudm.jpg
So it's something that doesn't make sense in Japan, emission, cold start etc.
Should be included in an EU wire diagram if you can get hold of one.

The EUDM solenoid pictured above looks identical to the 94-97 USDM solenoid that's mounted to the intake manifold. :)