First time swap. LQ9 into 95 OBS

[gagliano7]

I had the rubber hose connected to my fuel pump come loose and I was only getting 20 psi. Suprisingly the truck still ran like that but it would die if I went full throttle.. I had to go back in the tank( I take off front 6 bolts of bed and leave the 2 back bolts by tailgate loose and than I use my hoist to pull bed up like a dump truck to get to pump) and fix hose. That really sucked but I made sure that will never happen again. Your fuel pressure should be 58 psi.

[kewljay223]

which sending unit do you have?? this is the same pic from post 95 or something.



the one on the right is the newer style which i tried but wouldnt fit. so i had to keep the older unit but put the 381 pump on. look at the next pic. closer view and has a short hose. how could that fall off? im not saying your wrong, but i just dont understand what could have happend....



as you can see, there are the two white clamps that came with the kit which i sinched down as tight as i could. and yes the short hose also came with the kit so all of that is fuel rated.

if i dont find any signs of leaks, would it be ok to detach the hoses from the sending unit and apply 60psi of compressed air up to the rails and see if it holds? if it does then i would know for sure the problem lies in the tank...

[Mickeymotormount]

Not sure where you could be losing pressure. I'm using the same setup(left) and haven't had any problems. When I stripped the donor, I also took the fuel pump(right) and modified it to fit onto the older assembly. The truck ran but didn't start easily when hot. Took a couple of seconds longer before she would fire. After switching to the older setup with a new pump, the truck fires immediately cold or hot.

I would have to think there must be a check valve in the pump somewhere that holds pressure while the engine is off. I could be wrong.

[gagliano7]

Mine came loose where the rubber hose is attached to the pipe on your second picture. I had clamps on there good but the rubber hose must have shrunk or the clamp loosened and hose was loose. I replaced my clamps with the fuel injection clamps. The way I new it was in the tank I put a gauge before the fuel filter regulator on line from tank and pressure would only go up to 20 psi so I new it wasn't my fuel filter regulator.

[ccreddell]

You could also have an injector or two that are leaking. Any crap in the tank or lines could be keeping the injector from closing all the way. Also, what rev limit did you set in the tune?

[kewljay223]

yeah i finally got around to checking on it a little bit today and was going to ask if it could be a stuck injector or a busted pressure regulator. what leads me to believe that it could be an injector is that it runs a little rough at idle. almost like theres a bit of a lopey cam in there. and im also getting a code for o2 sensor. i thought it was due to my exhaust leak but it might just be all the unburned fuel a leaky injector is dumping on the exhaust stroke. so my next question is this.... since im gonna turbo it, im gonna need new injectors anyway. im thinking i should just go ahead and get some bigger ones and throw them on there. looks like the 76mm is what most guys are running for a stock setup and ill only be going to about 5psi. what would be a good injector size for this? and will in need to upsize the pressure regulator in the rail?

im thinking this might be a good route to go now since im in the middle of doing the 80e swap, i have to get the pcm tuned for the trans, might as well put the new injectors on and have them programmed in at the same time. and that leads me to one last question... bigger injectors just ALLOW more flow when needed correct (for under boost)?? they will still perform "like stock" without boost in which it wont be dumping more gas than usual and cause emissions issues. what im asking is will they pass the emissions test? im pretty sure it will, just want to confirm... thanks!

[gagliano7]

Make sure you don't run with the new injectors until it is tuned for them. You can wash down your cylinders in a very short time because to much fuel will be dumped until it is tuned. As long as the injectors are programmed correctly it will run like stock. Make sure you get injectors that have all the proper data so they work correctly.

[kewljay223]

Make sure you don't run with the new injectors until it is tuned for them. You can wash down your cylinders in a very short time because to much fuel will be dumped until it is tuned. As long as the injectors are programmed correctly it will run like stock. Make sure you get injectors that have all the proper data so they work correctly.

yeah i know im not supposed to run them without the pcm knowing. just seeing if they would be ok not on boost and you answered that. thanks! im new to the boost game but im learning... i can see that im going to be addicted once its on tho...

[jansen]

There's a bunch of 4l80 swap parts in the classifieds. Check out the thread (99-06 parts). Figured I'd give you the heads up.

[kewljay223]

thanks for the heads up. yeah i saw that. i have an obs so theres not much i can use besides the harness, but i can re-pin mine and get the vss conn from the local JY for a lot less than 50 bucks. lol all i really need is flexplate and dipstick tube but i can pick those up anytime locally.

im trying to decide if i should get a stalled TC that will work good now and later with turbo (which i can always upgrade if need be) or just wait until i get the snail and have some dyno numbers... decisions decisions!!

i know this doesnt pertain to the swap but i pulled off my ugly rusty drums and sh**** autozone brakes that are basically new. they squealed like crazy!! and that kinda thing drives me nuts. spent a lot of time removing rust which i absolutely dreaded doing and sprayed them with 3 coats of black caliper paint. its cool to have some shinny 20's but not cool when there is a huge chunk of rusty steel that they are bolted to!!!! i replaced the shoes with raybestos shoes, lubed the contact points with this stuff creates a "membrane" and wouldnt you know, they are quieter than a mouse!!! the expensive shoes and the time to make the drums "hide" was worth every bit. something so simple but im so happy i did it.