Replaced the injector spider 3 times, pressure regulator 3 times, and fuel lines once (incoming and return) and I'm still leaking gas into the plenum. New fuel pump and sending unit. I have 68psi with the key on and 62psi with the engine running. I have taken the plenum off approx 10 times now and it's puddled every time. Does the regulator have the ability to blow off excess gas or does it rupture the diaphram evey time? I had fuel running backwards through my return line (from tank to regulator) until I removed the vacuum line coming from the tank to the canister at the motor. Tried running the truck with the gas cap off but it didn't help. With the vacuum line off the fuel runs the right direction but it's still leaking in the plenum and making the truck miss really bad at idle. Would a bad MAP sensor cause enough of a pressure change in the plenum to make the regulator malfunction...? Thanks for any help.

 

I would say that something is wrong with the spider housing itself... After one FPR & 'nut kit' I would have tossed the spider in favor of a new one...

 

When I replaced the injector it came as a new spider housing and pressure regulator combo. All the lines are new as well. I can't afford to buy a fourth spider.

 

You cannot be doing things properly if a leak results every time you put new components in. And if you were doing things properly and a leak still resulted, why wouldn't you return the defective components? Something must be happening when you assemble the parts to cause this.

Your pressure is WAY high anyway. The regulator should hold the pressure to right around 60psi with the engine off.

The MAP sensor has absolutely no control over the vacuum pressure in the intake so it would have no impact on the operation of the FPR.

Are you sure you have the lines attached to the fuel pump properly? Something sounds very wrong with this truck in general. Sounds like way too much has been messed with without knowing how everything is supposed to be.

 

You said you replaced the nut kit once...have you checked it since then? which side is the gas 'puddled' on? Did you replace the o-rings/gaskets too each time you went in? Also, if there is an issue with the nut kit, the pressure will drop to 0 within 5 or 10 seconds of shutting the truck off. I am curious about why your pressure is so high, my 94 vortec runs 55 to 60 psi tops.

 

I have returned the injectors each time, the one on it now is still new. I check the system for leaks each time I re-install the plenum (which is 10 times now). The nut kit isn't leaking. I can turn the key on and it will hold a solid 68psi for over 30 min without dropping. The fuel line and return lines are both a different size at the tank so there is no way to get them switched. I have taken it to two different mechanics, both said it was the spider even though they couldn't find any pressure loss. I let one install the last injector and regulator to make sure I wasn't screwing anything up, and still the same results. It was money wasted. Th gas puddles 90 percent of the time on the regulator side. I am pretty sure it's coming from the hole in the regulator each time. When I replaced the fuel lines I bought fuel injector hose and clamps for $6 rather than the $50 nut kit. The mechanics said it shouldn't make any difference, but I'm wondering if the hose I installed is a slight bit smaller in diameter causing the pressure to raise 10psi too high, resulting in the regulator blowing out gas...?

 

Well, if the lines from the regulator were a LOT smaller, it could possibly cause the regulator to not function properly if it could not vent the fuel required to hold the pressure. A restriction in the return side would be the only thing that could cause the regulator to not maintain its set pressure properly.

How long have you had these "custom" feed/return lines under the plenum? Did you ever try the real thing? I do not know why people feel the need to "custom engineer" things they know little about in an effort to save a few bucks.

 

They are actually within an 1/8 of an inch of the original, and the return line is clean from front to back. I can blow through it and hear the gas bubbling in the tank. I have had these "custom" lines on since I found the crack in the original hose (approx. 3 weeks ago). And I felt the need to use a cheaper hose because it's 2 weeks til Christmas and after dropping $300 on the spider I'm a little broke...

 

I just took the plenum back off and both sides are soaked with gas. I'm gonna buy the nut kit tonight and see if that brings the psi's back within normal range.

 

With the plenum off turn the key on the prime the system see if you see and visible leaks, if time is an issue put a paper towel in there to catch the droplets.