Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: 86cougar on October 02, 2012, 02:01:56 PM

Title: Fuel pressure regulator
Post by: 86cougar on October 02, 2012, 02:01:56 PM
I got everything hooked up this morning and when I went to start the car it took a while to start. I realize that it would take a while for gas to reach the injectors. When it finally started, it was running rough (understandable). I turned it off and went to check the engine compartment and that's when I noticed some fuel on my manifold. I checked all the injectors and they seem alright. I have been known to reverse the fuel lines, so I reversed them hoping it would fix the problem. Now it won't start, so I'm going to put them back the way they were but I did not get any gas on my manifold either (probably from no fuel). The only gas that did come out was by the fuel pressure regulator. When I switch the fuel lines back, should I try to start the car and let it run until it settles down or do I have another problem? Why would I have a high fuel pressure problem if I've never had one before? Thanks!
Title: Fuel pressure regulator
Post by: 86cougar on October 02, 2012, 04:42:45 PM
I'm going to take the upper intake manifold off and check all the connectors to my fuel injectors. Yesterday I noticed one that was bent up maybe 1/16". I figure if I have one or two injectors not firing, that could be why I have high pressure. They would not be opening up and allowing fuel into the cylinder, also the reason it would run rough.
Title: Fuel pressure regulator
Post by: 86cougar on October 02, 2012, 05:23:08 PM
I took the upper manifold off and I found the problem. The fuel pressure release valve has been bent and has a crack in it. So, Now I need to find a new part. I'm sure I did it with as many times as I have taken the upper manifold off, I just wonder how long it's been like that. Should I plug it and buy an aftermarket fuel regulator or does this one have to be inline?
Title: Fuel pressure regulator
Post by: 86cougar on October 02, 2012, 05:48:34 PM
Looks like I'm talking to myself.... that's ok, I do it at home anyway. So, I don't quite get the purpose of this valve. It appears to be no different that a bicycle tire valve. You have to manually push it in in order to release pressure. As usual it is part of our emissions, so I can't remove the fuel regulator, but I can just put a bolt in place of this valve and run an additional fuel regulator in line.
Title: Fuel pressure regulator
Post by: 86cougar on October 02, 2012, 07:29:30 PM
Looks good! But of course I found another problem.
Title: Fuel pressure regulator
Post by: nbzimmer on October 02, 2012, 08:11:54 PM
I have no idea about this problem.  I am just posting to break up your string of consecutive responses to your own post.:)
Title: Fuel pressure regulator
Post by: 86cougar on October 02, 2012, 08:33:19 PM
(lol) I appreciate it! Nobody's going to talk to me today... They are thinking the same thing I am. I got a dead engine on my hands. Thanks for the laugh, I needed it!
Title: Fuel pressure regulator
Post by: Beau on October 02, 2012, 10:57:04 PM
Pretty sure there's no way you can hook the fuel lines up backwards, as one connector is bigger than the other.

Is your filter old? New ones aren't that much, although can be a PITA to replace if there's rust.
Title: Fuel pressure regulator
Post by: Haystack on October 03, 2012, 07:56:59 AM
Test your pressure, first.

If the fuel rails are bad, replace them. There cheap at a junkyard, and a new regulator used to be about $10. Fic it right the first time, so you can enjoy your car.
Title: Fuel pressure regulator
Post by: 86cougar on October 03, 2012, 10:07:26 AM
I put an NAS bolt with teflon tape in place of the valve. They sell the fuel regulator but not the valve. No big deal I would rather have a fuel regulator in line that has a gauge.
Title: Fuel pressure regulator
Post by: Beau on October 03, 2012, 12:04:33 PM
I wouldn't even bother with the hassle of an AFPR unless you've went to carb but kept the in tank pump, or have installed a high flow pump in a more stock car. Parts store regulator would be a better, not to mention cheaper deal, in my opinion. :)

And if your stock regulator is bad, it'll run decent at WOT, butt the idle will be piss-poor and you'll have a rich condition...basically there's a diaphram in the reg, it gets a hole in it, and raw gas goes through the vac line directly into the intake.

They're a little bit a pain to put on unless you take the rail off, but I wouldn't bother with an adjustable if the engine is all stock. I've got a 255lb/h Walbro in my Sport with a stock 5.0HO, and haven't had any problems with fuel issues in over 2.5 years.

Even then, I'd probably only use one if the fuel lines were different than stock, so as to keep the proper amount of PSI....our fuel systems are based in psi, not so much pounds or gallon per hour. Even a couple pounds less than what is ideal will cause weak starts, loss of power, etc on these engines.
Title: Fuel pressure regulator
Post by: 86cougar on October 03, 2012, 08:26:19 PM
TBS302,
            Presently, I have no way or telling what my fuel pressure is. That's why I'm thinking about buying one with a gauge. I need to know where it's at. Just about everything I have bought for this engine I can transfer to my next engine, so I don't worry about that. Even my old "62" Willy's has a fuel regulator and gauge (lol). Thanks for your help!