high fuel pressure hot start?

[mkiiichip]

In th process of freshening up my motor, while its out for a auto, to 5 sp swap. (which is a HUGE undertaking on a twenty year old motor, as most of you already know)

I found that one of the wires for the fuel pressure regulator vsv, was broken. (there were a few others broken wires but this was the only one i had no idea what the actual purpose was, on top of that, I have always had a heat soak problem since i bought the car).

After researching what the vsv was for, and finding that the fuel pressure was to be raised for a short while during hot start. i could not figure out what the purpose of this system was.

Why does it help hot start, to raise fuel pressure?

 

[mkiiichip]

no one knows?

 

[SupaMan]

im not sure why it helps, but i know when it doesnt work on some hot starts itll idle like complete dog shit. mine does it every so often.

 

[dumbo]

I thought it vented the regulator to atmospere so there was no vacum acting on it to keep fuel pressure at its highest for hot starts? I didn't think it had anything to do with idleing?

I don't even have one on my car, AFPR vacum line just hook right to the intake manifold. But cold starts sometimes i gotta crank for 10seconds before she fires...I think the CSI isn't working..

 

[SupaMan]

I thought it vented the regulator to atmospere so there was no vacum acting on it to keep fuel pressure at its highest for hot starts? I didn't think it had anything to do with idleing?

I don't even have one on my car, AFPR vacum line just hook right to the intake manifold. But cold starts sometimes i gotta crank for 10seconds before she fires...I think the CSI isn't working..

IIRC i asked jetjock about it and he said it sounded like the FPU VSV. i havnt looked into it as other things have been going wrong on the car and it happens randomly.

 

[dumbo]

IIRC i asked jetjock about it and he said it sounded like the FPU VSV. i havnt looked into it as other things have been going wrong on the car and it happens randomly.

Gotcha, whats IIRC mean?

 

[SupaMan]

Gotcha, whats IIRC mean?

If I Remember Correctly :icon_razz