So this is strange, I fixed the fuel line issue I had last weekend with a new hose section and changed the filter at the same time and got everything back together. Pump is moving a **** ton of fluid (sounds like a bilge pump in the tank), but for some reason the fuel system does not hold any prime at all. Starts fine and all that, but pressure instantly goes to zero as soon as its turned off. It didnt use to do this before, so not sure what happened with just a filter change. I double checked to make sure the filter is facing the right way, and everything after the filter is unchanged.

I am planning on putting the new cutout on this weekend along with a new muffler, so I will get some test videos of it in action. What I have in mind will be pretty cool

 

Failed check valve in the pump?

 

Maybe, but I tried both pumps and same thing. I never touched the pumps, just replaced that 2ft section of hose and changed the filter. :/

 

What kind of regulator do you have that maintains (or used to maintain) residual pressure? My Magnafuel regulator never would, and when I called thinking there was a problem, they told me that it won't .

 

I have an aeromotive 13101. Havent had any issues since I got it 7-8 years ago.

Interestingly with the truck running I squeezed the return hose while it was running and there is basically no pressure in that line with the return flow. I have a -8 feed and -6 return. Not related to the holding prime issue, just thought it was interesting.

 

So now you have to turn key and let the pump prime then crank? That can get annoying.

 

No, I can turn it and start it fine, and even if I just turn the key straight to crank it builds pressure fast enough that it starts fine. Its just very odd the behavior changed without really changing anything that would do that.

 

I wish I saw this a couple of years ago ago when I bought my boost activated cutout from sound and performance for 2X the money. FWIW I took it off as a boost activated cutout out Because after a few months it leaked and rattled really bad. I was able to repurpose for something else so it wasn't a total loss but I considered it to be a waste of money. Maybe those will last longer than what I had.

Also I put a little 12v pneumatic valve on the boost/vacuum line that went to my cutout. I could close the pneumatic valve under boost and the locked boost in the line would hold valve open if I wanted. Works the same with the vacuum actuated valves. Put a pneumatic valve on it to hold the vacuum and you should be able to keep it closed even under boost.

 

I got all of the exhaust done today. Replaced the muffler also with a stock one from a GMT900 of some year, but of course modified it to work with my exhaust. I cut my flowmaster merge thing shorter and welded in my cutout pipe, cutout, an intermediate pipe to the muffler, and my tailpipe. I reused all of the old pipes so its not that pretty but was cheap. I did get some new Vbands that are male/female from ebay and am very happy with them given their $25ish price.

For the cutout since you have to weld on a pipe inside of it to mount I took the cap from the QTP cutout pipe and cut out a hole in it to use as the mount for the cutout,


And this is everything together so you can see what I did. I also welded on grade 10.9 stainless bolts as studs to make it easier to remove and use the included gasket.


I haven't worked with stainless too much before but this seemed like a good time to practice, and I think it came out ok. I didnt bother backpurging any of this since nothing important is after it. I need some bigger filler, but this will do. Used 308 and 309 depending on which piece I was working on.


For the muffler since it is 3" inlet and outlet I left a few inches of pipe then made 3 slots and peeled it open to hopefully encourage some better airflow to it (not like it matters) and welded a reused 4" pipe around that and put a Vband on the other end.




Here is the inside of a stock muffler in case anyone was wondering.


I am hoping that super annoying rasp around 2000-2200rpm is gone now.

Here is a quick test video I made of the cutout, looks like it will work very well. I left a clamp off of the air gun so the air would drain out.

And when I was doing the exhaust I couldnt resist starting it with the open 4" pipe. Of course the video doesnt do it justice, but why not right. I did manage to scare some spiders out of it so that was good.


Tomorrows project is put the bed back on and figure out that fuel pressure thing.

 

Are those male/female vbands stainless? The one stainless ones will rust together and are a bitch to separate when the day comes. FYI