What the deuce is this thing?

[Spook50]

Over at Tonkota's place last week, we were trying to figure out what this brass looking thing on the back of the 3FE intake manifold is. There's normally a plastic gray cap that snaps on over the top of it. On his, the screw in the middle was missing completely, and on mine, it had come completely out (but was kept from being lost by the gray cap). I reinstalled the screw (which has a little black O-ring on it) and snugged it down, and it seems to have increased not only my mileage, but I noticed a decent seat-of-the-pants improvement in power. Felt like there was a noticeable increase in low end torque.

My question is, WTF is it?

[AATLAS1X]

I want to say Fuel pressure regulator, but ......Drivers side at end of fuel rail?

Shane

[Spook50]

Originally Posted by AATLAS1X

I want to say Fuel pressure regulator, but ......Drivers side at end of fuel rail?

Shane

IIRC the FPR is at the forward end of the fuel rail. I guess it's possible this could have some involvement in it though...

Edit: SOR shows it as a dampener at the "inlet" of the fuel rail. Possibly helping to subdue surges in fuel pressure that the regulator might not be able to keep up with. I could see where that might help with mileage, but with power too? I wasn't even expecting any difference when I reinstalled the screw, but I definitely felt something.

[Spook50]

Update: Replacing and snugging down that screw definitely made a large improvement in my gas mileage. On average I would get 10-11 MPG if I took I-90 across Washington (Spokane to Seattle and back). This time, even with the extra 475lbs of a slant six sitting in the back of the truck, I got 14.8 MPG.

Considering I was cruising along at 75-77 MPH and had almost 500 LBs of extra weight, I'd say that's a hell of an improvement.

I'm curious to see what it'll get the next time I go across via HWY 2 (which is where I got my all-time best of 17 MPG, probably due to staying between 60-65 the whole way).

So long story short, if you've got a 62 or an FJ80, check for that screw!

[billmc]

fuel pulsation damper

[tonkota]

I think I have one in my basement. I'll have to fix that now.

[Spook50]

Originally Posted by tonkota

I think I have one in my basement. I'll have to fix that now.

Be sure to lemme know if you see a difference in mileage on yours too. I guess that little screw kinda was important, huh?

[OlympiaFJ60]

Thanks Spook, one more thing to check out when looking these rigs over.

[Landpimp]

where abouts is it? I cant quite pin it down

[Spook50]

Originally Posted by Landpimp

where abouts is it? I cant quite pin it down

Look at your fuel rail, and it's at the aft end of it. It'll most likely have a gray cap snapped over the top of it. Work the cap off by hand and you'll uncover it. Careful though. If yours is like mine, the screw will very likely have worked its way out and can easily get lost.

[Landpimp]

ah yes.....that thingy......I think I poped the cap off once for some reason....better take a gander at it

Originally Posted by Spook50

Look at your fuel rail, and it's at the aft end of it. It'll most likely have a gray cap snapped over the top of it. Work the cap off by hand and you'll uncover it. Careful though. If yours is like mine, the screw will very likely have worked its way out and can easily get lost.

[Aseif007]

Originally Posted by billmc

fuel pulsation damper

X2, FPD.

[takeitforgranite]

Something tells me this thread is a candidate for FAQ.

[cruiser88]

Yep it is your damper and that blasted thing is known to leak.

It is reguired to remove the airbox if you need to tighten that thing down. BIG BLASTED METRIC WRENCH.

[tonkota]

Originally Posted by Spook50

Be sure to lemme know if you see a difference in mileage on yours too. I guess that little screw kinda was important, huh?

I'll check the mileage, but I won't be able to tell you if it was that little screw or if it was the camshaft that I just put in. I also won't be able to confirm a power increase (from the little screw anyway).

I was getting 13 no matter what I tried though.

[Spook50]

Originally Posted by cruiser88

Yep it is your damper and that blasted thing is known to leak.

It is reguired to remove the airbox if you need to tighten that thing down. BIG BLASTED METRIC WRENCH.

Are we talking about the same part? I can see where it'd be prone to leak, but looking at it, I wouldn't think I'd need to remove my airbox or intake hose at all.

Not that I want to try. The thing looks like a bitch to get to either way...

[cruiser88]

Originally Posted by Spook50

Are we talking about the same part? I can see where it'd be prone to leak, but looking at it, I wouldn't think I'd need to remove my airbox or intake hose at all.

Not that I want to try. The thing looks like a bitch to get to either way...

There may be a sst tool or something to remove it...i fawked around for over a hour to tighten that thing down with a wrench with no success.

In all honesty you can have the air box off and on within the hour if you are de-smogged.

[YODA 88 62]

It started leaking on mine about 6 years ago and is currently leaking. I used the smallest cresent wrench i could buy and managed to get it off without removing the intake. I think i paid around fourty bucks for the damper.

[cruiser88]

Originally Posted by YODA 88 62

It started leaking on mine about 6 years ago and is currently leaking. I used the smallest cresent wrench i could buy and managed to get it off without removing the intake. I think i paid around fourty bucks for the damper.

how. of course i have the biggest hands on the planet so that does not help

[YODA 88 62]

It looks like i bent the heat shield out of the way. That gave just enough to get the crescent wrench in.

[IB14A69]

Very interesting
I will have to check this out, if my 62 gets any quicker I wont be missing my sti

[sbisig]

I made the adjustment on my 92 FJ80. It needed a few turns with the screwdriver to tighten it down.

After driving it around home, it seemed to have better low end torque. The true test will be when I head over Snoqualmie Pass (hopefully tomorrow). I have a good baseline from traveling there last week (13.4 mpg gallon from Federal Way to Ellensburg, WA).

Steve

[Spook50]

Originally Posted by sbisig

I made the adjustment on my 92 FJ80. It needed a few turns with the screwdriver to tighten it down.

After driving it around home, it seemed to have better low end torque. The true test will be when I head over Snoqualmie Pass (hopefully tomorrow). I have a good baseline from traveling there last week (13.4 mpg gallon from Federal Way to Ellensburg, WA).

Steve

I just checked mine again last night while I was gassing up, just for shits and giggles (and to distract myself from the assrape being counted up on the pump) and it was coming out again. So I snugged it down again and noticed the same improvement in power. I figure it's worth checking every time you gas up, just to make sure it's still good to go.

I can't wait to drive across HWY2 and see what kind of economy I get out of it.

[GAS-A-LOT!]

where exactly? got a zoomed out pic?

[sbisig]

Originally Posted by GAS-A-LOT!

where exactly? got a zoomed out pic?

Look straight down over your engine, all the way to the rear, you'll see the plastic cap (or if lost, see the picture in the first post).

You can pop it off with your fingers.

Steve

[tonkota]

Originally Posted by Spook50

I just checked mine again last night and it was coming out again. So I snugged it down again and noticed the same improvement in power. I figure it's worth checking every time you gas up, just to make sure it's still good to go.

The Napa one I bought has a rivet, not a screw. I wonder why there is a screw there? Maybe manufacturing limitations at the time? Who knows.

EDIT:
I have not swapped them out yet, I am getting a feel for the power I have and I wanted to see if there was a power increase with the new part. Plus, I am going to pick up a cheap wrench for modification to change this part out.