LS1 fuel tank (Plastic 99-02 style)
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Yes, the 4th gen tank will work with the 5.0. LS1's typically use higher fuel pressure, so the pump in the 4th gen tank will have a higher output, however your regulator on the 5.0 should take care of it. The only other issue I see would be the vent and return lines that your IROC uses. The 4th gen tank has an self contained charcoal canister and I dont think it has a return line. If your in an area where emissions testing is important these might be things to consider as well.
The 5.0 reg won't "take care of it", because the plastic 4th gen f-body LS1 tank has the reg built into the return, and so will keep pressure higher than the 5.0 reg set pressure.
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Re: LS1 fuel tank (Plastic 99-02 style)
The reg is very easy to remove with just a screwdriver
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From: Los Angeles
Car: 1987 IROC-Z Camaro
Engine: 305 LB9
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Re: LS1 fuel tank (Plastic 99-02 style)
And as for the aforementioned charcoal canister issues...? (Sorry n00b here..)
And I definitely will have to get new lines correct?
And I definitely will have to get new lines correct?
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From: Clinton Township, Michigan
Car: 91 GTA, 73 Z28
Engine: 355, 6.0L
Transmission: TH350, 4L80E
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Re: LS1 fuel tank (Plastic 99-02 style)
new lines, you can use your thirdgen ones and slice them together unless youd like to make your own lines front to back. the charcoal canister is that ugly thing that barely worked on the inside of a thirdgens engine bay. most people delete them but a 4th gen has one built in. not necessary to remove them in fact they help for emissions and all that IIRC
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From: Turlock Ca.
Car: 1982 Z28
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Re: LS1 fuel tank (Plastic 99-02 style)
Thanks for the correction five7kid! I just got my plastic 4th gen tank and lines over the weekend and your correct, they do have a return line, also great point on the regulator, I forgot that the tank is internally regulated on the return side.
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Re: LS1 fuel tank (Plastic 99-02 style)
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From: AR
Car: 1991 Camaro RS Vert
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Re: LS1 fuel tank (Plastic 99-02 style)
(1)Fuel Sender Assembly
(2) Hose (EVAP Canister to Vent Solenoid)
(3) EVAP Vent Valve
(4) Fuel Tank Harness
(5) EVAP Canister
(6) Fuel Tank
(7) Overpressure Relief Valve
(8) Fuel Tank Pressure Sensor

just found this and i think it will be helpful to anyone trying to think through their plastic tank evap setup
(2) Hose (EVAP Canister to Vent Solenoid)
(3) EVAP Vent Valve
(4) Fuel Tank Harness
(5) EVAP Canister
(6) Fuel Tank
(7) Overpressure Relief Valve
(8) Fuel Tank Pressure Sensor

just found this and i think it will be helpful to anyone trying to think through their plastic tank evap setup
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From: AR
Car: 1991 Camaro RS Vert
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Re: LS1 fuel tank (Plastic 99-02 style)
So there are 4 lines...
Send
Return
Line off item 5 goes to engine vac source correct?
What about line off item 7?
Send
Return
Line off item 5 goes to engine vac source correct?
What about line off item 7?
Joined: Mar 2000
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
The one coming off of the EVAP canister with a QD on it but no number goes to a solenoid on the engine.
Nothing is attached to #7. It just hangs out.
Nothing is attached to #7. It just hangs out.
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From: NJ
Car: 92 Firebird
Engine: 4.8 LR4
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Axle/Gears: 3.45 9 Bolt
Re: LS1 fuel tank (Plastic 99-02 style)
#7 is the pressure relief incase the tank starts to build too much pressure
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From: AR
Car: 1991 Camaro RS Vert
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Re: LS1 fuel tank (Plastic 99-02 style)
Ok, on an LS engine, it goes to a solenoid, but for TPI it would just go to a vac source then.
#7 just hangs. oh, I thought my hose was cut and it went to something.
Thanks, I think I have this figured out now.
#7 just hangs. oh, I thought my hose was cut and it went to something.
Thanks, I think I have this figured out now.
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From: Los Angeles
Car: 1987 IROC-Z Camaro
Engine: 305 LB9
Transmission: 700r4
Re: LS1 fuel tank (Plastic 99-02 style)
For a TPI I have to get a vacuum line for EVAP? And connect where?
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From: Harlingen,Texas
Car: 88 Iroc ls1 swap
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Axle/Gears: original disc
Re: LS1 fuel tank (Plastic 99-02 style)
All of this sounds like alot of work and complicating..... woundnt it be easier and give the same performance putting a gss340 pump and a fuel pressure regulater even though its a little pricey for the regulater....!!!!!!!!!!!!! sorry just want know cause im going that route
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Car: 1991 Camaro RS Vert
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Re: LS1 fuel tank (Plastic 99-02 style)
Penguin, You dont have to put it to a vac source. But I dont like the smell of gas fumes, so I'm connecting to a vac source to burn the fumes. Lots of others let it go to nothing.
Iroc. Your talking about a pump.
Iroc. Your talking about a pump.
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From: Omaha, NE
Car: 1988 Camaro IROC T-Top
Engine: 350ci TPI
Transmission: TH-350
Axle/Gears: 4.11 Posi
Re: LS1 fuel tank (Plastic 99-02 style)
I assume you have to run some sort of vac back there to control the pressure regulator?
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From: Humid Houston on the Texas coast
Car: '86 Z28
Engine: SDPC TPI 350
Transmission: WC T5
Axle/Gears: 3.23 posi
Re: LS1 fuel tank (Plastic 99-02 style)
LS1 regulator design does not use idle high vacuum unload. I know TPI cars used it but the LS1 regulator is pure spring pressure. Fuel pressure is constant regardless of throttle position.
M
M
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From: cincinnati ohio
Car: 91 camaro rs
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Re: LS1 fuel tank (Plastic 99-02 style)
i currently have a 305 tbi in my car now...my plans are to remove complete fuel system and make it out of aluminum 3/8 line and run a 4th gen fuel filter. no if i run the 4th gen filter would i have to do any thing to the fuel regulater that is in the stock pump. correct me if im wrong but the only time you have to remove it is wen ur going to use the vette filter?and i already have the 4th gen tank and the new fuel sending unit ready for intall
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From: Lawrence KS
Car: 91 z28
Engine: LS1
Transmission: 4L60e
Axle/Gears: 10 bolt 3.42
Re: LS1 fuel tank (Plastic 99-02 style)
i currently have a 305 tbi in my car now...my plans are to remove complete fuel system and make it out of aluminum 3/8 line and run a 4th gen fuel filter. no if i run the 4th gen filter would i have to do any thing to the fuel regulater that is in the stock pump. correct me if im wrong but the only time you have to remove it is wen ur going to use the vette filter?and i already have the 4th gen tank and the new fuel sending unit ready for intall
Joined: Mar 2000
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
There is no reason to run a Vette filter with the LS1 plastic tank.
3rd gen EFI filter, 3/8" aluminum tubing, LS1 plastic tank:
3rd gen EFI filter, 3/8" aluminum tubing, LS1 plastic tank:
Re: LS1 fuel tank (Plastic 99-02 style)
Using the setup shown above, what causes pressure to be built up in the fuel line to the fuel rail (engine)? Seems to me that if there is no restriction, the flow would be through the filter and immediately return to the tank via the return line. Very little flow and virtually no pressure would be available to the fuel rail......
Just curious.
Just curious.
Re: LS1 fuel tank (Plastic 99-02 style)
Sorry, just remembered the fuel pressure regulator is in the RETURN side of the sending unit on the LS1. That is what causes the buildup of pressure to the fuel rail.
In my best Emily Litella impression - "Never mind"........
In my best Emily Litella impression - "Never mind"........
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From: Omaha, NE
Car: 1988 Camaro IROC T-Top
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Re: LS1 fuel tank (Plastic 99-02 style)
If you look back through the thread there's actually one disassembled.
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From: CT
Car: 1992 RS
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Re: LS1 fuel tank (Plastic 99-02 style)
Wiring is fairly simple. Gray wire is fuel pump feed wire. Black wire is ground and purple is level sensor wire.
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From: Los Angeles
Car: 1987 IROC-Z Camaro
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Re: LS1 fuel tank (Plastic 99-02 style)
I know almost nothing about electrical, but it seems disconcerting that only three wires run to the stock pump while there are around eight running to the LS1 pump. I can still just cut the connectors and splice the three from the old connector to the three of matching color and just ignore the rest and it will work?
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From: Tacoma, Wa
Car: '91 TA vert
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Re: LS1 fuel tank (Plastic 99-02 style)
You're thinking of the main bulkhead connector that also has wires for the purge solenoid and such. The LS pump setup is almost the exact same number of wires, you just need to add a ground since the tank is not metal.
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From: Los Angeles
Car: 1987 IROC-Z Camaro
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Re: LS1 fuel tank (Plastic 99-02 style)
EDIT: I think I understand, the black wire with the white stripe is ground, the rest are the same. Sorry to inconvenience you guys.
Last edited by penguinpanda0; Apr 14, 2012 at 03:49 PM.
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Re: LS1 fuel tank (Plastic 99-02 style)
The hard lines under the car can be the same. But you will need to get adapters for the tank end, the line end, then run an "AN" line in between.
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From: Clinton Township, Michigan
Car: 91 GTA, 73 Z28
Engine: 355, 6.0L
Transmission: TH350, 4L80E
Axle/Gears: 3.42, 3.73
Re: LS1 fuel tank (Plastic 99-02 style)
run an or go cheap and do rubber hose, not suggested but if you rally need to drive the car itd be a temporary fix.
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From: In the Garage
Car: Camaro
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Re: LS1 fuel tank (Plastic 99-02 style)
V6 tank is the same and so far as I know the pump is also the same. I can tell you this much its strong enough to run a head/cam LS1 for 3 years lol. Theres no internal reg on the V6 tank though so use the vette filter and you'll be fine
Re: LS1 fuel tank (Plastic 99-02 style)
Sorry to be a bother but im still a little confused.
1) I have a 92 TBI
2) 1999 v6 plastic tank
3) have all plastic lines leaving the sending unit
?: where to buy the "T" bracket ?
?: Do i order the ls1 fuel sending unit from hawksthirdgen?
?: Will i have to remove the regulator off the ls1 sending unit?
?: Could i just change the pump to get more pressure and keep the stock sending unit, or does the pump not separate?
?: What about the an line? how do I know which ones or sizes to get, or how the connector pieces fit?
Please let me know or give me a number where i could call you and hear word for word instruction.
1) I have a 92 TBI
2) 1999 v6 plastic tank
3) have all plastic lines leaving the sending unit
?: where to buy the "T" bracket ?
?: Do i order the ls1 fuel sending unit from hawksthirdgen?
?: Will i have to remove the regulator off the ls1 sending unit?
?: Could i just change the pump to get more pressure and keep the stock sending unit, or does the pump not separate?
?: What about the an line? how do I know which ones or sizes to get, or how the connector pieces fit?
Please let me know or give me a number where i could call you and hear word for word instruction.
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From: Clinton Township, Michigan
Car: 91 GTA, 73 Z28
Engine: 355, 6.0L
Transmission: TH350, 4L80E
Axle/Gears: 3.42, 3.73
Re: LS1 fuel tank (Plastic 99-02 style)
help section at auto parts strore
not necessary just use the stock v6 unit
if you have the v6 sending unit i believe it should work
ur running tbi you dont need more pressure. youll need a regulator with the v6 pump probably as an ls1 would be overkill for tbi id think.
not necessary just use the stock v6 unit
if you have the v6 sending unit i believe it should work
ur running tbi you dont need more pressure. youll need a regulator with the v6 pump probably as an ls1 would be overkill for tbi id think.
Re: LS1 fuel tank (Plastic 99-02 style)
On Friday, November 23, 2012. I completed my 4th gen gas tank swap.
Parts Used:
1) 1999 V6 Camaro Plastic Tanks (I pulled it myself so I had all the plastic lines connected to the sending unit)
2) 1992 305 TBI Engine
I did not worry about the gas gauge because it did not work before I made the swap. (I always travel with a 5 gal tank of gas filled. Plus when you drive your car to the point were it runs out of gas, you have a feel to when your car is about to run out) Sure enough my old tank was cracked around the solder, fuel neck and tank. (GM claimed there was no leak).
The car ran fine, used the 1999 camaro fuel filter. I connected the metal lines from the plastic tank to the metal lines of the car with a rubber hose. (This is what was on the car when I removed the old tank so I just used it to make my job easier. I was going to flare the lines using a double end flaring tool but I changed my mind.)
I must say I am satisfied with the results. I filled the tank up to the neck, and drove from Lakeland/Brandon/Tampa/ FL to Tallahassee FL on one tank of gas. (It use to take me two to three tanks with the old tank.)
Sorry I did not take pics of my process, however I am more than will to lead you through the steps to get the job done.
Thanks to everyone on this site who helped me in any way with performing this task.
Parts Used:
1) 1999 V6 Camaro Plastic Tanks (I pulled it myself so I had all the plastic lines connected to the sending unit)
2) 1992 305 TBI Engine
I did not worry about the gas gauge because it did not work before I made the swap. (I always travel with a 5 gal tank of gas filled. Plus when you drive your car to the point were it runs out of gas, you have a feel to when your car is about to run out) Sure enough my old tank was cracked around the solder, fuel neck and tank. (GM claimed there was no leak).
The car ran fine, used the 1999 camaro fuel filter. I connected the metal lines from the plastic tank to the metal lines of the car with a rubber hose. (This is what was on the car when I removed the old tank so I just used it to make my job easier. I was going to flare the lines using a double end flaring tool but I changed my mind.)
I must say I am satisfied with the results. I filled the tank up to the neck, and drove from Lakeland/Brandon/Tampa/ FL to Tallahassee FL on one tank of gas. (It use to take me two to three tanks with the old tank.)
Sorry I did not take pics of my process, however I am more than will to lead you through the steps to get the job done.
Thanks to everyone on this site who helped me in any way with performing this task.
Last edited by 92camaro_man; Nov 26, 2012 at 10:17 AM.
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From: Texas
Car: 1989 IROC LSX
Engine: Swapped LS6 Forged by LME
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Re: LS1 fuel tank (Plastic 99-02 style)
I am currious about one thing that I don't see here. On the 99 ls1 pump there are 4 wires going to the pump. The Orange W/Black stripe is a LO Reference wire, Are we not doing anything with this wire? I would guess this would be the ground for the sender??
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From: Lawrence KS
Car: 91 z28
Engine: LS1
Transmission: 4L60e
Axle/Gears: 10 bolt 3.42
Re: LS1 fuel tank (Plastic 99-02 style)
Senior Member

Joined: Dec 2009
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From: Texas
Car: 1989 IROC LSX
Engine: Swapped LS6 Forged by LME
Transmission: 4L65E
Axle/Gears: 3.73
Re: LS1 fuel tank (Plastic 99-02 style)
Thanks, sadly I have not been able to open any links on this site for a week or so, Including that link to the pin out...???
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Car: Camaro
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Re: LS1 fuel tank (Plastic 99-02 style)
^Not that Im aware of.
In other news a bit of an update worth sticking in here. The original Russel fuel rail adapter fitting shown on the left side here;

has been known to randomly BLOW OFF thus spraying fuel everywhere so anyone who has one should upgrade to the new version that has no plastic clip shown on the right. Also I might as well add that the stock metal clip style retainer clips ( see attached pic below ) work great and have no issues. Obviously not for all purposes as boosted guys need mo bigger lines but these are proven durable and support most NA applications. Be careful with fuel.....

In other news a bit of an update worth sticking in here. The original Russel fuel rail adapter fitting shown on the left side here;

has been known to randomly BLOW OFF thus spraying fuel everywhere so anyone who has one should upgrade to the new version that has no plastic clip shown on the right. Also I might as well add that the stock metal clip style retainer clips ( see attached pic below ) work great and have no issues. Obviously not for all purposes as boosted guys need mo bigger lines but these are proven durable and support most NA applications. Be careful with fuel.....

Last edited by cam-; Aug 31, 2013 at 08:30 AM.
Joined: Jun 2009
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From: Lawrence KS
Car: 91 z28
Engine: LS1
Transmission: 4L60e
Axle/Gears: 10 bolt 3.42
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From: Moneta, VA
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Re: LS1 fuel tank (Plastic 99-02 style)
The shop doing the LS1 swap on my car is hooking up the evap I believe. Do you have any certain questions you need answered?
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From: PA
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Engine: LS1 (not stock...)
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Re: LS1 fuel tank (Plastic 99-02 style)
You can have evap work perfect. But you need to use the ls1 gauge cluster if you want a fuel gauge. Ls1 pcm sends fuel level as serial data...which also contains information for the evap system to function. If you try to hook up a traditional style fuel gauge that sends a reference voltage to the sender, you HAVE to sever the connection to the pcm and it botches the whole works. Note:4th Gen guys that run traditional fuel level gauges disable evap in the process. (Simplified short explanation)
You cant trick it like other systems with resistors, because the level and pressure in the tank is constantly changing. Even if you fool it into venting like its half full, it won't be working "properly" the other 99% of the time.
If your shop gets it to work without the ls cluster, without mounting another sender in the tank, and using all 4th Gen parts you GOTTA post up!! I'de love to hook evap back up.
J.
You cant trick it like other systems with resistors, because the level and pressure in the tank is constantly changing. Even if you fool it into venting like its half full, it won't be working "properly" the other 99% of the time.
If your shop gets it to work without the ls cluster, without mounting another sender in the tank, and using all 4th Gen parts you GOTTA post up!! I'de love to hook evap back up.
J.
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From: Los Angeles
Car: 1987 IROC-Z Camaro
Engine: 305 LB9
Transmission: 700r4
Re: LS1 fuel tank (Plastic 99-02 style)
As far as evap... I'm using the plastic tank with a 305 tpi engine. I never ran a vacuum line to the tank for emissions. Now I'm doing my egr system, and I notice that the egr solenoid is supposed to connect to the old charcoal canister that I no longer have. My goal is to have a functioning egr system and a functioning evap system so that I can hopefully pass CA smog. How would I route my vacuum lines to do this?




