Fuel pressure issue, multiple potential causes
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,309
Likes: 20
From: Woodstock Georgia
Fuel pressure issue, multiple potential causes
Ok, so the car has begun to idle high after traveling down the highway. I'm talking in the 1000-1100 rpm range when stopped, but I can feel it pushing the car when I left off the gas. I suspected the pcv or IAC. Upon popping the hood, I notice the pcv sitting outside of the valve cover, most likely a result of a 10 psi romp, but I haven't done that in a while.
I re-inserted the pcv and went to the passenger side and noticed that I was only getting 25 psi of fuel pressure. I also found that my new BBK rail mount fuel pressure gauge has leaked almost all of its oil onto my valve cover.
Anyway, I attempt to adjust my AFPR on to find that it's extremely difficult to turn (I'm using the Holley model with large finger dial). I get it to turn finally by initiating with a pair of pliers, but I can't get the psi over 30. My main question is, could this be the gauge going bad, or the AFPR? Both pieces have not much more than 500 miles on them.
Thanks. Oh, car is an 86 stock engined with Vortech blower, Walbro, headers, etc.
I re-inserted the pcv and went to the passenger side and noticed that I was only getting 25 psi of fuel pressure. I also found that my new BBK rail mount fuel pressure gauge has leaked almost all of its oil onto my valve cover.
Anyway, I attempt to adjust my AFPR on to find that it's extremely difficult to turn (I'm using the Holley model with large finger dial). I get it to turn finally by initiating with a pair of pliers, but I can't get the psi over 30. My main question is, could this be the gauge going bad, or the AFPR? Both pieces have not much more than 500 miles on them.
Thanks. Oh, car is an 86 stock engined with Vortech blower, Walbro, headers, etc.
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,309
Likes: 20
From: Woodstock Georgia
Yikes! That doesn't sound good. Nothing that a bad PCV valve could cause, huh? I haven't noticed any puffing when I've checked the crankcase pressure (removing the oil fill cap and feeling for pressure variations at idle, recommended by Greg at Blowerworks to check for damage after my meth injection hose popped off at about 4000 rpm). I guess I need to do a compression check.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Pcv
I have seen a couple pcv valves stick closed, and they don't pop out,they let the seals blow the oil out down by the pan.
could it be that you blew out an intake manifold gasket, and the blower pressure is blowing into the crankcase?
could it be that you blew out an intake manifold gasket, and the blower pressure is blowing into the crankcase?
Instructor
Joined: Dec 2005
Posts: 188
Likes: 0
From: Riverside CA
You have some testing to do on you FP issue.
On the PCV,
You ar running an additional V cover breather right?
If so whats your pcv valve doing poping out unless you hav a LOTof Blow by. That much pressure should also be blowing oil out your breather and all over the valve cover(s)
When you make boost you ar going to have some blow by.
There are 2 kinds of rings. Those that leek and those that will.
Where will the blow by go? It cant get sucked out by the PCV:Its hooked to an intake manifold under boost pressure.
You may know this my friend but I seen other posts from people stating that there PCV and dip sticks will not stay where they belong.
Just wondering how many guys runing Turbo/ S.C with no breathers
Good luck on FP
Chad
On the PCV,
You ar running an additional V cover breather right?
If so whats your pcv valve doing poping out unless you hav a LOTof Blow by. That much pressure should also be blowing oil out your breather and all over the valve cover(s)
When you make boost you ar going to have some blow by.
There are 2 kinds of rings. Those that leek and those that will.
Where will the blow by go? It cant get sucked out by the PCV:Its hooked to an intake manifold under boost pressure.
You may know this my friend but I seen other posts from people stating that there PCV and dip sticks will not stay where they belong.
Just wondering how many guys runing Turbo/ S.C with no breathers
Good luck on FP
Chad
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,309
Likes: 20
From: Woodstock Georgia
I'm running the PCV on the driver's VC, and a breather hose routed to the blower intake on the passenger side which, I would think, be plenty of evacuating draw. Perhaps one of my check valves isn't up to snuff. I can say my dipstick has never popped out!
I'm so not looking forward to pulling this ****ing penum again, that I think I'm gonna switch to an MRIII intake. That way, things like this fuel pressure issue will be much easier to work on.
I'm so not looking forward to pulling this ****ing penum again, that I think I'm gonna switch to an MRIII intake. That way, things like this fuel pressure issue will be much easier to work on.
Thread Starter
Drifting
Joined: Dec 2005
Posts: 1,309
Likes: 20
From: Woodstock Georgia
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