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Discussion Starter #1
Hey guys! So my question is about a Carb to FI swap on a 1984 El Camino v6 OBD set up. Donor car I have is 1996 Caprice.

I am in the final stages, already acquired all the parts I believe I need for a successful LT1 swap for my Elky.
I bought a new fuel tank, one for a 1985-87 EFI, I have yet to order the pump or sender unit. I am being told by the Smog Ref that fuel and evap. system have to match the donor car.

Question is, how do I make the fuel system set up work with the OBD2 set up it will have now? What other tanks fit the El Camino G Body but run the OBD2 system and evap?
 

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my swap into the '84 came from a '94 caprice with an OBD1...look at my posts for reference help with the new tank and pump. I reused the old sending unit from an old 1985-87 EFI tank that I got but didn't use..hope this helps somewhat but its been done by plenty of others on here, I'm sure they'll start to jump in.
 

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I am at the exact same place with my EC only the donor is an 04 GTO LS. I'm just getting ready to mount the fuel evap system but my issue the the fuel tank pressure sender which is mounted as a fixed unit in the GTO fuel level assembly. I found a FTP sensor that fits about a "jillion" vehicles from 1996 to 2011. I'm going to try to T off the vent line that goes from the tank to the charcoal canister to see it that will monitor tank pressure. Plus originally we only installed 2 o2 sensors but had to go to 4.

Lots of goofing around to meet these federal standards.
 

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The tank pressure sensor is designed to be operated by the ECM. On startup, it closes one valve ( vent valve, ) and opens the other (Or vise versa). It then measures the pressure in the tank to be sure you don't have any leaks. Once it's sure you don't have any leaks, the valves reverse, and you keep going. If you have a leak, a code is set ( infamous check gas filler cap!)

Some LT1's were pre-OBDII ( May still use that style port, but sort of OBD 1.5). These may not have the pressure sensor- just can't remember.

I know some guys were using the Roadmaster wagon tank as a substitute- that might be another option to consider.
 

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Discussion Starter #7
I know some guys were using the Roadmaster wagon tank as a substitute- that might be another option to consider.
How is that possible if the filler neck on those comes out the back, behind the license plate? El Camino's is on the drivers side.
 

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I think the wagon models had the gas filler on the side. I know the filler neck had to have a cut, and connected by filler hose. It was done several times successfully- try a search on the site.
 

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The tank pressure sensor is designed to be operated by the ECM. On startup, it closes one valve ( vent valve, ) and opens the other (Or vise versa). It then measures the pressure in the tank to be sure you don't have any leaks. Once it's sure you don't have any leaks, the valves reverse, and you keep going. If you have a leak, a code is set ( infamous check gas filler cap!)

Some LT1's were pre-OBDII ( May still use that style port, but sort of OBD 1.5). These may not have the pressure sensor- just can't remember.

I know some guys were using the Roadmaster wagon tank as a substitute- that might be another option to consider.


Thanks Darbysan and JJLT1 too
You guys helped me out on mine and no, mine didn't have the pressure sensor (OBD I) it just had a 2PSI one way check valve and I installed my vapor canister w/bracket sideways on the pass. side rear on top of the frame between the fenderwell and taillight area. So Jesse, that location might be an option for you, so far it works for me
 

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What Darbysan said. I used a tank from '94 Caprice wagon. Filler pipe is a separate piece joined to the tank with flex hose, like from a gas station pump. weld a little bracket onto the frame below the gas filler door to support the filler pipe.
 

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I sure am glad I don't have to deal with that crap. It makes zero sense for the gas tank to match the donor car, especially when the current platform has a suitable EFI tank.
 
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