ROFL, anyone who read the original post, ignore it. That wasn't the vacuum line I pulled off.

So I have 34 pressure with vacuum line connected and disconnected it gets up to 41. So, what do you all think? Fuel pressure holds steady after priming.

 

What was the pressure with the vacuum line on and then off?

 

Rofl, see edited post.....

 

It's low for certain(compared to mine).

 

Are you actually having any problems? 41-47 is the normal range with the hose off.

 

What about hose on? The main problem is actually just an intermittent misfire which I am sure is the injectors. Once the misfire starts, the gas gauge needle starts bouncing, too.

 

Is a sparkplug wire arcing to a wiring harness?

 

I'm pretty sure it's not, but I'll run it in the dark for the third time just in case. :P

 

The vaccum compensation line adjusts the fuel rail pressure (what the gauge indicates) in proportion to intake manifold vacuum. With a stock cam, a 7psi drop when you reattach the vacuum line would be normal.

The pressure starts to "bounce" with misfires, because misfires cause the intake manifold vacuum to "bounce". Classic way to look for misfires, misadjusted valves, burned valves, etc. is to hook up a vacuum gauge and see if the vacuum is steady (good) or bouncing (bad). The bouncing isn't causing the problem - it is the result of the problem.

 

Okay, that's what I figured Fred. Thanks for confirming it! Because it is so intermittent but consistently there, I am going to go ahead and pull the fuel rail and look at the spray patterns. I am betting that is it.

One question though, if a clogged injector is causing a misfire, would stomping on the gas while accelerating seemingly make it go away? It seems to do that.

 

No. But what if its a dripping injector? A small drip will affect the idle and low load operation. But when you go WOT and use max fuel, the small drip becomes insignificant.

 

Ahhh.. Gotcha. Time to pull the fuel rail. Any tips I should know on doing that? I can pull it and put it back on in an hour or two, right?

 

Shouldn't even take that long. All you need it the fuel line disconnects and remove the 4 bolts on top of the intake and wiggle it out. Obviously relieve the fuel pressure before disconnecting the lines, assuming there is any.

 

Why would you use a fuel disconnect, when you are going to pressure the system to check for drips, and spray pattern? Loosen the metal clip that clamps the two hard lines. Leave the fuel lines intact. Then just raise the rails. No need to disconnect the lines. Done it that way numerous times.

 

Because I'm an idiot and read pull the fuel rails

My bad.