Is your truck a v8 or v6 4.3l?

 

It's a 262 4.3 v6 I thought I mentioned that in the first post, guess I didnt..

Okay okay. I called gmp back (I call them for general engine questions, the motor isn't a gmp one it's stock) and they clarified that it's the return evap line. (I asked them if it was a "return line" the first time and they said "yes".) That would've been good to know the first time i called....

So I was wrong thanks for trying to throw that info at me, I'm just frustrated with this mess and swapped the same setup over from the s10 and it worked perfectly on that truck.

heres my next question, I have a marine intake from the old setup (with fuel feed and return line). I want to use this instead of the current manifold, so I can tune it myself and not have huge bills or headaches. Can I use the existing steel evap line (that I installed my fmu on) as the return line and then make a new line for evap?

How do I go about running an evap line... I know I just need a vacuum source which I can tap for, and route a new fuel line to the tank, but can I just drop the tank and drill/tap/istall a fitting for the new evap line??? Will this work? I don't see why it wouldnt...


But it does have a cpi poppet style injector system, had no idea this thing was returnless.

Thanks again for the help guys, I'm just stubborn when I cant figure somethin out. wkdivr- that's directed toward you, hope I didn't **** yall off too much with my first few posts

 

Can I swap a gas tank and the fuel pump from a '99-'03 silverado, and use the marine intake manifold set up with the correct fpr on the rail... can this work on my truck? I'll probably need a pcm from a '99-'03 truck as well.

Problem with this returnless system is I'm limited to the 19lb/hr injectors. Wynjammer sells 36lb/hr injectors for it, but with that I'm still limited to around 280-290 hp. With the marine intake I can run an fmu and/or whatever size injectors I want, so it's limited to how much the internals can take, which is between 350-400 hp.


Question is, will the injectors pulse at what the '99-'03 pcm is telling it to? Or will I always have issues with the injectors if I delete the old turbine style fuel pump/in-tank fuel pressure sensor and fpr? I mean are the injectors on their own harness to the pcm and the pcm tells the injectors what to pulse at independently?

... if I swap to the older computer will it tell the injectors to pulse like it doesn't know any differently... or will it freak out because of the unused/unplugged wiring and sensors from the returnless style fuel tank?

btw if possible this would still pass emissions because it's a ULEV (ultra-low emissions) with over 50,000 miles so It's now tested as a LEV and the '99-'03 trucks were also under the LEV emissions.

 

i would keep the existing lines as a feed and a evap or either run a new feed line and use the old feed as a return or just add a return line with a new fpr and just bulkhead it into the fuel tank and bypass the the stock fpr.

if the pcm is like any of the newer ones on the gen 3 trucks . your pcm can control a slew of injectors and just needs to be tuned for the correct ones you choose.