Buckle up guys, let me take you for a ride. First of all, new spider assembly (bwd) last January. Worked good up until Christmas Eve and on my way up to the ski hill something went and it immediately lost a lot of power and the throttle response said goodbye. I barely got it back home without getting towed, it would stall out at red lights and when I stopped moving. I had my scan tool hooked up and it was showing very negative fuel trims so I had a good idea of where to look. When I got the plenum off there were puddles of gas in the intake manifold so it was clear the spider was leaking from somewhere, I was going to hook the fuel lines back up with the plenum off to prime the system and check for where it was leaking and made one of my worst mistakes ever. Dropped the non-magnetic fuel line nut down an intake port! So next I just pulled the spider and got a warranty replacement because it was obviously leaking from somewhere. I then took off the intake manifold so I could get that nut out and replaced the gaskets while I was in there. I got it all back together at last and it ran worse than it did with the other spider! It would barely start and when it did, it was very rough. Took the plenum off again to find the new spider was leaking fuel!! I hooked up the fuel lines with the plenum off and primed the system and confirmed drops of gas leaking from the bottom of the spider unit. So off to go get another warranty replacement I went. I put this new spider in, hooked up the fuel lines then primed the system and could see no leaks. Got everything back together and it's still misfiring and running really rich, I haven't let it run for that long because it just smells so bad like gas when I start it, it's obvious something is wrong still. I pulled the plenum off again to find more new puddles of gas in the intake manifold even with this newest spider installed, gas could also be seen on the inside of the plenum, mostly in the very back. But I cannot find any leaks when I connect the fuel lines and prime the system without the plenum on. However, it does not make sense for puddles of gas to be in the intake manifold if the spider was not leaking. It also does not make sense that when I prime the system and check for leaks I can't see any but when I put it all back together and start it I end up with puddles of gas in my intake. It should be noted fuel pressure fluctuates erratically from 50-60psi when it's idling as seen from my gauge. I'm wondering if anyone has any other thoughts about this to confirm what's leaking on the spider as I am running out of ideas. Pictures below of the newest spider after I had started it and pulled the plenum back off to find more gas everywhere, the puddle of gas in the back right below the regulator is making me think something is wrong with the regulator but this is also what I thought with the last spider too because gas was puddling in the same spot and it turned out it was leaking from the very bottom.

 

Something binding on the spider when the plenum is on?

 

Thanks for the reply Les, I don't think this is the case here because the plenum seems to go into place easily and does not seem like it's interfering with anything when I bolt it down. I think I will connect the fuel lines again and prime the system in a bit to check for any leaks again in case of the odd chance I missed the leak the last two times. It's really confusing me that I can't find any leaks with the plenum off but I start it up and end up with gas in my intake and it's still misfiring!! The gas must be coming from somewhere. Would it be possible for the regulator to only leak under a vacuum?

 

Do you have compression on the cylinder with the port next to the fuel? Wondering if bad intake valve (bent or something) blows fuel back into under the plenum when fuel is injected. Lots of ifs on that! Would also explain running very poorly. Just some speculation.

 

The first question is - does it leak statically (key on) or while the engine is running or both? Do the fuel pressure leak down test in the sticky and see what is happening with your pressures. If they hold then the excess gas only arrives when the engine is running. You have replaced the spider twice (third spider) and no change in the problem?. Has the regulator been replaced during any of this? Are you getting the same spiders from the same source?


George

 

I don't own a compression tester so have no way of telling for sure on that. However when I pulled the plenum off it definitely looked like the gas was leaking down into the intake ports, I could see where it was leaking down into the #5 port right next to the puddle, and didn't look like the gas was coming up through there. George, I will do a proper leak-down test when I go out and prime the system to check for leaks again and report back with what I find. I have hooked up the gauge with this new spider and I know it primes to 55 or 56 psi and definitely does not leak down fast. But I will do a proper test waiting the specified time and see if the leakdown is in spec. It's looking like it's only leaking while the engine is running because I've tried to prime the system with the plenum off and I cant see it leaking from anywhere. Yes that's correct this is the third spider now, the first one almost left me stranded after being in for nearly a year, the second one I confirmed was leaking out of the bottom, and now this one. All the spiders are the same model (bwd 63885) I'm getting warranty replacements.

 

finger in spark plug hole?

 

Okay, right after it primes it's at 56psi, after 10 minutes it's at 48psi. The regulator also comes new with each spider George... During the 10 minutes, I watched the spider and again could not find any leaks. But again, the gas must be coming from somewhere. I will take a look into what you are saying, Les. It's just so weird that I can't find it leaking but pop the plenum on and start it and have gas all over.

 

There may be a difference between your leakdown test with the plenum off and everything reassembled. That may be a clue. Because you failed the leakdown at the schrader you may want to go to the fuel filter and remeasure just to make sure that all your problems are at the intake. Leaking at the intake can be return to the tank, internal plenum leaks or leaking injectors into the cylinders.


George

 

Okay many thanks, George. Being that I'm having problems with gas all over in my intake, I think we are safe to conclude my problems are lying somewhere in the spider yes? This still however sheds no light onto why I'm getting puddles of gas in my intake when I start the engine but I cannot see any leak with the plenum off. Any internal plenum leak you would think I would be able to see while I'm priming the system with the plenum off, a leaking injector(s) would leak gas down into the cylinder(s) but it also wouldn't cause the puddle I'm seeing I don't think. I suppose it could be leaking back into the return, this would be working with the regulator would it not? It's seeming more and more convenient to blame the regulator here, I just cannot see it leaking to confirm it. Especially because the puddle of gas is right below the regulator and most of the gas found inside the plenum was right at the back near the regulator. What do you guys think? How can I confirm it's the regulator that's messed up for 100% before I go pull it back out and try to get yet another new spider under warranty.