First time swap. LQ9 into 95 OBS

[gagliano7]

hey everyone. just a quick update. not much info as i have worked everyday since i last touched the truck... but i ill finally have all day tomorrow to hopefully get the wiring finished. i wrote down EVERYTHING i need to do. got all the wiring figured out... I THINK.. lol but something just crossed my mind....

i have bought the ac delco 381 pump along with a new 98 fuel sending unit (the whole in tank module) which came with a pump and all...i bought the new unit because it comes with the pressure sensor which i need for emmissions. i was gonna swap in the new pump and buy the EXPENSIVE ASS SUBMERSIBLE HOSE from napa but then i thought WAIT A MIN!!! isnt the newer style pump and hose already rated for the higher fuel pressure due to it being made for the vortec style motor? what im asking is do i really need to take they time to swap those parts off the unit or can i just drop it in and run with it???? obviously that would be the preferable way.... let me know!!! im about ready to swap the unit out! thanks!

Your new style pump and hose will work fine. That sending unit was made for the higher pressure. The only thing that you may have a problem with is your fuel gauge but i may be wrong.

[kewljay223]

cool. thats the kinda answers i wanna hear!! lol that makes things a lot simpler. luckily for me its just a simple swap. it will take longer to drop the tank then swapping it. haha. got a lot done on the wiring. not cleaned up yet tho but heres yet another rats nest to show off.


got my pcm back the other day too so once i get this mess cleaned up i can drop it in there and get everything plugged in and wires tucked away. unfortunately im gonna be on a plane to texas tomorrow for buisness. should be able to get back on the truck by wed.

[gagliano7]

I tilted my bed up like a dump body by removing frony 6 bolts and loosing last 2 bolts or take bed off. Way easier than dropping tank in my opinion.

[kewljay223]

hey. been a while. was stuck in texas longer than i thought. not much as happened. but does anyone know what the obd1 pinouts are for my truck? its got six wires on it. i brought the new pcm data wire in for the new connector and now i need a 12+ and two grounds. i was thinking of just utilizing what is there if possible. i see two blk/wht wires which i assume are grounds and there is obviously a 12+ on it somewhere too. but ive got the old harness already cut up and battery isnt connected yet so i cant really trace them. anybody know which ones i can use? and there is no reason to keep the obd1 connector even though im still using my old pcm also right?

[kewljay223]

hey mickey (or anyone else that may know) how did you connect the newer style PS pump? the new pump has 3 nipples on it and my old one only has two. ive been trying to look at the escalade diagrams and it seems there is a PS cooler but the way it seems its routed is that there should still only be two nipples on the pump.... i cant tell from the diagrams. do i just put a crossover tube between two of them? and which ones? which nipples are for what? i honestly have no idea where to connect whatever hoses.... im assuming i can utilize the new pump right?

[Mickeymotormount]

You can use the new pump. Just be sure the low pressure(return) goes to the center of the pump. I found this out the hard way. My original pump for the 6.0 was used to power the Hydro boost brakes as well. So I had two return nipples to choose from on the pump. I chose the one on the top and brazed the center one closed. After running it, the pump whined like it had no fluid. Turned out the return nipple I chose was dumping fluid into the pump and aerating the fluid. That's when I looked at other pumps and found they all had the returns to the center of the pump. Eliminates aeration of the fluid and feeds the center of the pump all at the same time.

[kewljay223]

i hate learning lessons the hard way.... thanks for the heads up. so i should plumb the return to the center, cap off the top since its not needed, and the remaining will be the high pressure supply to the gear box correct?