Hey all I think I need a little help. What does an adjustable fuel pressure regulator do? Can it lower fuel pressure? Ever since I put this big Walbro in my car it has been running overly rich. The S-AFC doesn't seem to compensate enough for it. So before I throw more money at an adjustable FPR I need to know that it's going to do what I want it to do, which is, lower my fuel pressure. I'm looking at the Aeromotive A 1000 6 FPR right now which is supposed to be adjustable between 30-70 psi or something like that.



Thanks,

Michael

Yes, you can lower the fuel pressure with it, provided that you're not using the stock regulator as well. If you place the aftermarket FPR after the stock one then you can only raise the pressure.

umm that's the one i got. have fun hooking it up LOL

Can I disable the stock fpr by removing and capping the vacuum line nipples or do I need to remove the fpr completely from the fuel rail?



Why do you say that vosko? How hard could it be?

The only thing the vacuum line does to the factory regulator is raise the fuel pressure when decelerating for emissions.



But if you disable that I'm not sure what the factory ECU would do, might experience lean decelerating = backfiring.

Well my vacuum rack and emissions are ALL removed. So, I don't see how that would effect it. Not saying you're wrong I just don't see the relationship. Plus, the only connection to my FPR is a single vacuum line leading to the UIM.



If I'm missing something let me know.

So, it probably needs to be installed after the fuel filter but before the primary fuel rail?

On the 89-91 motors the stock FPR is welded to the fuel rail. Using an 87-88 TII secondary rail would be a better idea. Check out http://fc3s-pro.com/TECH/MODS/FUEL/fpr.htm for setup tips.

So, it probably needs to be installed after the fuel filter but before the primary fuel rail?[/quote]

NO, you MUST install it after the secondary rail. Installing it before the fuel rails will cause many problems. https://www.nopistons.com/forums/pub...DIR#>/wink.png

So, it probably needs to be installed after the fuel filter but before the primary fuel rail?[/quote]

NO, you MUST install it after the secondary rail. Installing it before the fuel rails will cause many problems. https://www.nopistons.com/forums/pub...DIR#>/wink.png[/quote]

Heh, good thing I don't give automotive advice for a living....Thanks for the link Ace. Now I see why putting that FPR in is somewhat of a major undertaking. I'll probably go back to a smaller pump for now.

So, it probably needs to be installed after the fuel filter but before the primary fuel rail?[/quote]

NO, you MUST install it after the secondary rail. Installing it before the fuel rails will cause many problems. https://www.nopistons.com/forums/pub...DIR#>/wink.png[/quote]

Heh, good thing I don't give automotive advice for a living....Thanks for the link Ace. Now I see why putting that FPR in is somewhat of a major undertaking. I'll probably go back to a smaller pump for now.[/quote]

Don't worry about the rich idle. It's not a big deal. A good fuel pressure gauge would tell you how your fuel pressure is.

Heh, actually I sold that Hi-pressure Walbro today and ordered the lo-pressure walbro at the same time. plus I took my injectors in to get cleaned, so I'll let you know how that works out for me.

BTW the engine was getting SO much fuel that it wouldn't start and lacked all power. I have an S-AFC to tune the injector cycle but if fuel is blowing by the injectors thats a problem.

Ok, you win. https://www.nopistons.com/forums/pub...#>/biggrin.png Let us know how it is when you get it back together.

Ok, you win. https://www.nopistons.com/forums/pub...#>/biggrin.png Let us know how it is when you get it back together.[/quote]

Yeah! hopefully I won a running T2.

Ok, you win. https://www.nopistons.com/forums/pub...#>/biggrin.png Let us know how it is when you get it back together.[/quote]

Yeah! hopefully I won a running T2.[/quote]

I tried a Walbro once, but it never seemed to work properly.

Ok, you win. https://www.nopistons.com/forums/pub...#>/biggrin.png Let us know how it is when you get it back together.[/quote]

Yeah! hopefully I won a running T2.[/quote]

I tried a Walbro once, but it never seemed to work properly.[/quote]

that makes two of us :unsure:

Ok, you win. https://www.nopistons.com/forums/pub...#>/biggrin.png Let us know how it is when you get it back together.[/quote]

Yeah! hopefully I won a running T2.[/quote]

I tried a Walbro once, but it never seemed to work properly.[/quote]

that makes two of us :unsure:[/quote]

It would hardly ever start on the first try. I think that the stock pump may have a valve that helps to maintain pressure in the fuel lines.

That didn't seem to be the problem here. I would pull the plugs after attempting to start mine and the plugs would be soaked in fuel.

I can't wait till I get the new pump tomorrow. Hopefully, it pops right over.

Hopefully it's not your stock FPR. My friend had one fail and it wasn't releasing any pressure.

mine starts on the second click with the walbro in it

So they're all like that?

Hopefully it's not your stock FPR. My friend had one fail and it wasn't releasing any pressure.[/quote]

I've been thinking it would be good to test the stock FPR as well. I just haven't had the time or tools. With the NA pump in the car ran fine, when driven around the block at low rpms. So, I'm hoping that means the FPR is fine. The new pump came in this morning and as soon as I get my injectors back, I'll let ya know what happens.

Hopefully it's not your stock FPR. My friend had one fail and it wasn't releasing any pressure.[/quote]

I've been thinking it would be good to test the stock FPR as well. I just haven't had the time or tools. With the NA pump in the car ran fine, when driven around the block at low rpms. So, I'm hoping that means the FPR is fine. The new pump came in this morning and as soon as I get my injectors back, I'll let ya know what happens.[/quote]

The best way is to get a fuel pressure gauge.

So they're all like that?[/quote]

i dunno. maybe mine is *special* https://www.nopistons.com/forums/pub...>/rolleyes.gif

So they're all like that?[/quote]

i dunno. maybe mine is *special* https://www.nopistons.com/forums/pub...>/rolleyes.gif[/quote]

Yes, special. :P

"Special" like the little bus....



Yea! my car runs again!! I put the low pressure walbro in and it starts up fine. I have a power issue, but I think its still running rich. I pulled my plugs and the front rotors plugs are black i.e. rich condition. The rear rotors are spotless however ?! Also, boost is low, maybe around 6psi at WOT. I attribute the low boost to the rich condition =, but the rear plugs looking spotless while the fronts are black puzzle me. Surely, I connected the injectors back correctly?? Correct me if I'm wrong but the injector plugs are wired by rotor and not by primary/secondary right?



And "yes" the timing and coils are good.

Nevermind that last post. It all works now! All I can say is OMFG! so much better than the stupid NA!