I will be replacing the fuel pump on my '92 Z28 and needed some help:

1. I went up to 24# injectors - should I use a better fuel pump?
2. Can anyone recommend an aftermarket fuel pump?
3. Any hints on making the replacement easier?
4. Anyone know the part number for the 1LE tank?

I appreciate any and all help. Thanks guys, and think SPRING!

------------------
92 Z28 - 5.7 - Black/Grey Leather
Macewen White Faced Guages
SLP T-RAM, 24lb/h Injectors
Accell 52mm Throttle Body
SLP 1 3/4" Headers and Cat Back Sys.

One Awesome Camaro Site!

 

I think 24# injectors might be overkill, some people here including myself would think that you would get better atomization of your fuel with 19# injectors or at the largest 22#. As far as pumps, I use a GM Syclone pump on mine but now I wish I had bought the Walbro.

------------------
Kevin Irving
85 Trans Am WS-6, 305 TPI, custom burned '86 PROM with '87 "165"ECM, Accel Supercoil & 8.8 Wires, MSD 6AL, Aluminum Driveshaft, TB Coolant Bypass, Ported Plenum, Modified MAF, Syclone Fuel Pump, JET Airfoil

15.556 @ 86.65mph, Nov 10, 2000.... I know it sucks.. but it will get better!

http://www.geocities.com/transam85tpi/

 

I just finished replacing a bad puel pump in my '86 IROC. It was suprisingly easy, but I had access to a lift, air compressor and alot of tools. Took me 8 hours. This is not a weekend project for most people. You need to remove the driveshaft, e-brake cables and drop the rearend out of they way. Then the exhaust system from the converter (stock, or in most cases) has to come out. With the axle gone exhaust removal is easy. Then the heat shielding for the tank and the tank's lines have to come off. Make sure your tank is empty when you do this...Removing the tank is a pain!!!Be sure it's unfastened from the fuel door. Then snake it out. Don't force it, you'll bend it(worse). Make sure you put the pump's sock on correctly oriented and look closely at the original pump and the new pump...make sure the polarity is right (or it'll pump backwards). You'll probably have to bend the filler neck up an inch anyway after you put it back in. Use a little grease (wheel bearing works good, but don't use too much!!!)on the tank seal when putting the pump in the tank. Also make sure the wires on the sending unit/ fuel pump don't interfere with the level indicator on the pump. The sock could also interfere. I wouldn't worry too much about the 1LE tank (but it is a nice bonus)unless you really corner hard. Make sure the tank is suitable for reuse...at the very least, seal it (takes a day). I used a Walbro high pressure pump(kick *** !). It's supposed to support 570 something HP @ 13.2 volts. It's $134.99 from Cotton's performance. They use this pump on GN's and such. Some GM vehicles also use Walbro pumps, I've seen them in a few Tahoes and Blazers(?). Don't try to get one from GM, though. The PN is #GSS340M(139.95). It comes with the pump, seal, fuel hose, etc...Should fit all EFI thirdgen's. They were very understanding and willing to help. The phone number is (413)789-0531 (cottonsperformance.com)GMHTP's magazine also ran an article on thirdgen swaps, it's the Jan. 2001 issue. I think that covers everything. But before you do that, are you SURE it's the pump? Check the fuse? relay? wiring? Do you hear the pump come on when you turn the key to run?(usually the bast way to tell is to check all three, the relay makes and audible 'click' is it works when you turn the key). Just checking, because it's a pain to swap these. BTW: before you button up the pump, double check EVERYTHING. After you do that, CHECK AGAIN. Nothing's worse than having to tear out one of those again due to crossed wires, etc. Good luck. Let us know if we can help.-dhirocz

 

I agree on the in-tank Walbro pump for your setup. The 340 will supply enough fuel to support almost any future mod you do (Nat. asp.).

24lb injectors are way too big for your setup. You don't need to increase the injector size unless you change max RPMs or change engine size. You can run the 24s with no problems but ONLY if you have a PROM change for 24lb injectors (26lb if you are using SVOs because they are rated at a lower pressure and therefore flow more at the higher GM pressures).

Tim

------------------
TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

 

Thanks for the help guys. I didn't want to hear that the 24#ers would be too much, but I knew it before I started. I got the injectors for free with the T-Ram and figured they would be in better shape than my old ones... Any more comments would help.

I have drained the tank and started to get the rear end out yesterday, so I'll be pulling the tank this week end... is this a good time to replace anything else?

 

The exhaust is extremely easy to get to, so if you planned on it, now's your chance. The fuel filter should also be changed. Driveshaft, LCA's, and a axle service are all things to consider...look at what you've got while it's out and see? If you've got a stock exhaust, there's usually more things wrong with it than you think, you'll see while it's out. I dropped mine complete (cat-back)so I wouldn't bust anything. The sending unit in the tank is a good choice, but they're kind of pricey, so only do it if it's a suspect of going bad. Don't forget to seal the tank, and be sure to use the proper sealants!

 

back from the dead

what do you use to seal the tank?

 

8 Hours to Change the Tank ?

Geez.

I got the last one out in 45 minutes... In my Driveway.

The very first time I did it, it only took 4 hours round trip, and that included figuring out where it was leaking.


The Walbro 340 is the perfect pump Choice, Forget about the 1le tank.

As far as the injectors, Tim is right ( Duh )

You can Run them just fine with a PROM change. ahem (signature)

lol

EDIT: I should also mention,there is no Need to remove the Rearend or driveshaft. I simply remove the lower Shock mount, and lower the Rearnd to its fullst reach ( with the torque arm and panhard rod attached it won't stress the brake line too bad )

Then unbolt the exhuast at the cat, and Slide it to the passenger side, sort of Diagonal.

Then Monkey the tank out. Easiest if empty, for sure.

Finally, To Quote the Good Old Helms Manual "Reintallation is the reverse of Removal"

 

yeah we had tank out in less than an hour on the lift, we just unbolted exhaust pipe at the cat and took system off the hangers in the rear and swung system out of the way

rear axle doesnt need to be dropped far, just undo the lower shocks and remove the bars behind the axle and thats it

 

WOW, i was i lil shocked when i seen 8 hours, i took me about 2 in and out with a non experienced friend. remove some pan hard rod bolts and shock bolts, remove muffler and thats about it....

 

I would like to know what this means also. The sender on the top has an o-ring. Are they saying to add some additional sealer in this area to make sure that there are no leaks??

 

nothing to seal tank cept the new O-ring seal that coems with new pump, just makes sure that some of it doesnt fall into tank while you are turning the locking ring ! hehe

 

My brother-in-law has this down to a science, he goes in through the hatch. He just pulls the carpet back and cuts three sides in the floor above the tank and pulls it back right above where the fuel pump is. It doesn't take anytime at all. I was afraid he would cut into the tank and he was not even close. :rockon: :rockon:

 

I'll revive this too. So if i were to go with a super charger in the near future, could i use this pump, the GSS340M? Is there a pump i could use that would work well in an N/A situation as well as a forced induction one? Thanks for your time.

 

guys I've never changed a fuel pump on a thirdgen before, I took a look underneath the car yesterday to see what I would be getting into, and after I picked my jaw up off the ground, I decided it might be a little much for a driveway swap. This thread has been more than helpful however. I do have one question... If I unbolt the shocks, am I going to have to worry about the coil springs at all, or will I be OK on that front?

 

You should be fine. When i went to put in my new springs, the rears just fell out. Nothing really to it. The fronts were another story though. I thought they were going to "pop" out but they just kinda stayed in there and i had to knock them out with a sledge. I did not have the car high enough, but yes, you should be fine just as long as you watch what you are doing. It looks like a lot but i am sure it is just time consuming more than anything. Plus the pain in the *** bolts! Good luck
edit: good point to check the coil locations before sitting them back in! Also, with my new springs, i had to get a spring compressor tool to get them in there. It looked as if i could just put the stock springs back in without the tool though. But if you are dropping the rear, it should not be a concern, just have someone else help you with the springs once it is time to raise the rear back into place.

 

When you let the rear hang they will just basically fall out. Nothing to worry about there. Just index them right when you put them back in if you take them out. Make sure the end of the coil is in the same spot in relation to the perches for both springs.