i have 2 92 z28s w/350s i bought as a package.
im planning on selling one of them but it needs a fuel pump, given how much freaking work it is to replace a stock pump, can i just put an electric in-line pump outside of the tank and leave the old broken one in the tank? its stock, and all i want it to do is run well enough to sell

anyone know what voltage i should get at the plug that goes to the pump? i assume 12 but it reads 9v, not sure if that may be the problem.
car starts for 1/2 second and dies, i dont hear the pump running

 

No you can't do that, 9v is enough, or at least that's what mine read when I did it and it works fine.

Its not that much work, you just have to break a lot of rusty bolts. But you can just get new ones at home depot. Unless you live in a non-rusty state, then its easy.

So it does start for second though? Try tapping on the gas tank w/ a rubber hammer a couple times, see if it runs longer.

 

Why can you not just put an in-line pump and leave the old one?

 

because the pump inside the tank will become a restriction, and end up being a problem. We have done it on a tbi system, before we knew better. We ended up fixing it the right way within a month. Fix it right or fix it twice, its up to you.

 

From my experience, 9V at the pump is a problem. Get a full 12V (or more like 14V with the engine running) to the pump and see what happens.

 

what could be causing the low voltage problem?
with the inline pump i only need it running well, doesnt have to be able to handle future mods. there are a lot of rusty bolts, its a ny car, and i really dont want to go through what looks like days of work to get a new pump in the car. any tricks to make it easier? can i cut a hole i in the sheet metal?, sounds extreme,but so is the work to do it the right way.
to put 12v to the pump, which wires do i need to power, the center is the ground, which side is power to the pump?

 

Purple is the fuel gauge sxender wire.

Low voltage could be the result of poor connections at the pump relay or socket, the oil pressure switch, the FP/ECM fuse and holder under the hood, the FP connector under the rear seat, and possibly the fuse link at the battery. You should check voltage at the FP/ECM fuse while the pump is running to determine if the voltage is low at that point. If voltage at the fuse remains constant, you can concentrate on the relay abd FP harness and its connectors.

 

its funny, the whole thing with American cars, in all the stuff ive worked on over the years ive never seen a car where a problem at the oil press switch could create a problem with voltage at the fuel pump. Only in America! could engineers take something so simple and turn it into such a mess. not to say the cars arent good, they just are sometimes much more of a science project than they need to be.
i hate to rant but i have another post about the loose steering column, another rediculous problem should never be a problem, and another few hours work to tighten 4 bolts
on the bright side this is a freaking great forum, never got good answers and expert advice so fast anywhere else
thanks again guys
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if i was half the man i used to be i would find out where it is and cut a 4 inch hole in the sheetmetal above the tank and replace the stupid pump that way

 

Thats how I replaced mine. Cut a hole in the sheetmetal. Its right in the middle of the hump. It was so easy.

 

check your pms

 

and yes cutting the sheetmetal above the fule tank does work but be carfull and try to make it look nice put metal back over the hole when your done, not just carpet.

and i never liked the fact that to fix the fuel pump you have to drop the entire rear end either, but i guess thats what happens when they make our cars so low and compact.

 

F--- it, where do i cut?
how big of a hole?

 

You're going to be using the "F---" word a lot more if you cut a hole in the floor, replace the pump, and find out it does the exact same thing with only 9 volts supplied to it.

 

vader
i already am saying F--- a lot over this car
i put 12v straight to the plug and got zip, so pump must be shot, but i still cant figure the 9v problem either,
i probably will run 12v fused from elsewhere in the car to power the pump, that should be fine right?
this project already has fiasco written all over it, my garage is full of other projects, sleds, supermoto bike and the better camaro, so this whole mess is going on outdoors in relentless rain that lasts all spring up here, day in and day out from march till may, worst weather in the world is in my zip code. supposed to be sunny today, rain since the moment i got up with no end in sight, about 45 degrees, im laying under the car with the freaking worms in my driveway, my freaking arthritis is killing me, i hate it

 

Another one of these threads. Its not "days worth of work", and you generally do not have to remove the entire rear end. I didnt even loosen the shocks when i did mine. just had to get the exhaust out of the way. Start to finish it took a few hours,with smoke breaks.

Before you do anything, try jumping 12v to the pump and see if it comes on. If it still doesnt, drop the damned tank and fix it, dont ruin the car because you are lazy.

Also, the oil pressure switch thing isnt only in america, its actually a pretty common thing.

 

Well said. Only way to do anything is the RIGHT way. All the cussing and knuckle busting is what makes it soooo worth it when you drive it away.
You just have to be smarter than what you are working on.

For a while I thought I was getting a cold with all talk of hacking on this thread .

 

im such a hack
i put 12v to it and got nothing, then did the unthinkable, i admit it, im a scumbag, i cut it.
i dont know where you guys are but this is a NY car that has seen a few salty winters, and days of work is broken shock bolts, track bar bolts for that matter every bolt under the car, and worse yet, rusted exhausts that only come apart when theyre cut
this is not a NICE car, its decent though, i bought a pair and one is nice, this one is just getting sold to pay for parts for the better of the two, probably pretty cheap as well.
anyways, i cut it like a jerk and it runs, seems to run perfect even with the 9v problem, i guess im getting what i asked for though cause it looks like it needs head gaskets
gonna change fluids and clean everything up and see tommorow, its been sitting for 3 years so who knows what i got

on the bright side, you guys got a kick a$$ board here thanks for the help

 

well glad to see you got it running and yeah rust belt cars suck to pull apart, snaping every other bolt you touch is so frustrating but at least ya got it working