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I just bought a LT1 gen 5 and 8L90e combo for my '55 Chevy. I'd like to keep the stock returnless fuel system. What are my options and part numbers? Thank you, Harry
IIRC, the fuel system would be similar in concept to a diesel engine, the triangular lobe on the cam operates the high pressure fuel pump to the injectors, and then it just needs a lift pump from the tank to the high pressure pump. I would think that you can use any PWM style in-tank or external electric fuel pump to supply the HP pump and trigger it through the stock ECU wiring. I can't speak from experience with swapping a Gen V though, but I'm sure someone will chime in.
yes i'm doing the same thing in my 55. I've heard a few options on not going with the return less fuel system. But thinking of buying new factory parts to install to mimic a stock chevy truck. Fuel pump/sending unit, pwc controller and it should wire up to the stock harness? Can that be done. Seems like everyone is saying its a hassle. I'm not exactly there yet but wish i could hear a bulletproof solution to this.
I am in the same boat. LT1 into 88 Camaro. So far, I see three options. #1 is the GM performance controller kit. Still not sure this will work on engines other then crate. #2 Vaporworx seems to have a standalone kit but I know nothing about it. #3 is a setup like the LS swaps. Higher pressure with return line.
I am in the same boat. LT1 into 88 Camaro. So far, I see three options. #1 is the GM performance controller kit. Still not sure this will work on engines other then crate. #2 Vaporworx seems to have a standalone kit but I know nothing about it. #3 is a setup like the LS swaps. Higher pressure with return line.
I like this Hotrod link. That doesn't seem to hard. Assuming the factory harness i have that i need to be reworked for stand alone will have a connector to control the PWM computer. The plumbing is fairly easy and it spells out what pump to use. I can handle this. I just maybe need to understand more about the stock engine harness and the ECU programming. Thanks for that link.
I like this Hotrod link. That doesn't seem to hard. Assuming the factory harness i have that i need to be reworked for stand alone will have a connector to control the PWM computer. The plumbing is fairly easy and it spells out what pump to use. I can handle this. I just maybe need to understand more about the stock engine harness and the ECU programming. Thanks for that link.
If you like that link, this one is better. Plus his website
The pump that is referenced in the article is a Gen5 ZL1 fuel module. ACDELCO PN MU2101. It has the same pumping section and output as the Gen6 ZL1/Gen3 CTS-V but is shorter and easier to adapt to most retrofits.
If you have the GM wiring harness/ECM that includes the Fuel System Control Module this is the easiest and least expensive method for a true pulse width modulated returnless system. There is no programming that needs to be done unless there are changes made to the engine. It's pretty much plug and play when used with MU2101. Note in the Hot Rod article the need to modify the Aeromotive hat to allow some fuel to bypass at idle. This is needed for smooth PWM control, hence, just hooking up the FSCM to an in-line or in-tank pump will likely result in poor pump performance. The MU2101 needs no such modifications.
If the wiring harness used does not have the GM FSCM a VaporWorx controller can be used with the MU2101 pump with good results. All that is needed from the ECM is the fuel pump enable signal. The kits typically come with wiring tailored to suit the chassis.
As noted, Rick's Tanks in El Paso has a limited offering of stamped steel tanks that can accept the GM fuel module, or a custom tank can be made. Rock Valley Antique Auto Parts can also make a custom tank. VaporWorx offers a RetroWorx kit that includes a recessed tray and pump mounting ring, or for those that don't mind some sheetmetal work, just the mounting ring to modify a stock tank.
The fuel pressure sensor, as noted in GM's and VaporWorx's installation instructions, needs to be mounted near the outlet of the fuel module.
There are no additional filters, regulators, or return lines needed with the MU2101. The Aeromotive setup will require an external in-line filter. From a cost standpoint, it's usually a wash, but the GM modules are light years better than anything available in the aftermarket. There are features built into them that no aftermarket company offers that greatly increase pump life and performance. The GM module also has built in filtering and a safety blow-off valve, again something that the aftermarket does not offer. Comparing aftermarket offerings to the newest fuel modules offered by any OEM is an apples vs. oranges comparison.
From a tuning standpoint the ECM is assuming sufficient pressure and volume are available at the injector inlet, downstream of the high pressure pump. The in-tank pump and FSCM are acting as a lift system to get fuel to the mechanical pump.
The pump that is referenced in the article is a Gen5 ZL1 fuel module. ACDELCO PN MU2101. It has the same pumping section and output as the Gen6 ZL1/Gen3 CTS-V but is shorter and easier to adapt to most retrofits.
If you have the GM wiring harness/ECM that includes the Fuel System Control Module this is the easiest and least expensive method for a true pulse width modulated returnless system. There is no programming that needs to be done unless there are changes made to the engine. It's pretty much plug and play when used with MU2101. Note in the Hot Rod article the need to modify the Aeromotive hat to allow some fuel to bypass at idle. This is needed for smooth PWM control, hence, just hooking up the FSCM to an in-line or in-tank pump will likely result in poor pump performance. The MU2101 needs no such modifications.
If the wiring harness used does not have the GM FSCM a VaporWorx controller can be used with the MU2101 pump with good results. All that is needed from the ECM is the fuel pump enable signal. The kits typically come with wiring tailored to suit the chassis.
As noted, Rick's Tanks in El Paso has a limited offering of stamped steel tanks that can accept the GM fuel module, or a custom tank can be made. Rock Valley Antique Auto Parts can also make a custom tank. VaporWorx offers a RetroWorx kit that includes a recessed tray and pump mounting ring, or for those that don't mind some sheetmetal work, just the mounting ring to modify a stock tank.
The fuel pressure sensor, as noted in GM's and VaporWorx's installation instructions, needs to be mounted near the outlet of the fuel module.
There are no additional filters, regulators, or return lines needed with the MU2101. The Aeromotive setup will require an external in-line filter. From a cost standpoint, it's usually a wash, but the GM modules are light years better than anything available in the aftermarket. There are features built into them that no aftermarket company offers that greatly increase pump life and performance. The GM module also has built in filtering and a safety blow-off valve, again something that the aftermarket does not offer. Comparing aftermarket offerings to the newest fuel modules offered by any OEM is an apples vs. oranges comparison.
From a tuning standpoint the ECM is assuming sufficient pressure and volume are available at the injector inlet, downstream of the high pressure pump. The in-tank pump and FSCM are acting as a lift system to get fuel to the mechanical pump.
Good writeup. I am leaning toward the Chevy control system since it includes everything except the pump. I am hoping I can get the Rick's Tanks bolt in ring kit # 27000 to fit my tank so I can use the GM pump. It would make life so much easier.
Good writeup. I am leaning toward the Chevy control system since it includes everything except the pump. I am hoping I can get the Rick's Tanks bolt in ring kit # 27000 to fit my tank so I can use the GM pump. It would make life so much easier.
I've been emailing with Speartech all day and they make a PWM fuel system and said to use Rick's tank and pump made for PWM. Any thoughts on using their system.
I think 99.9% I'm going to buy from Speartech. Justin has been very responsive with emails and has given me info as I ask for it.
Standard harness
PWM fuel controller
Floor tap shifter
Gear shift indicator
PWM fan controller
Tune ECU and TCM
He told me that they tune out the AFM with swaps. Does this mean I don't have to do anything else with that? I saw AFM delete kits that come with lifters and oil port plugs. Does this mean I have to do that right now also? Or is tuning it out of the ECU the only thing that is necessary?
Last edited by GoobKustomz55ChevyLT; Jan 25, 2018 at 09:29 AM.
I spent several days researching companies to supply the wiring harness and I chose BP Automotive because of the quality and it was the best priced by several hundred dollars. https://www.bp-automotive.com/produc...one-harnesses/
I don't have an LT, but an LS7 running Vaporworx system. All I'll say is if you guys want a surefire fuel management system and the best customer service and tech support on earth...go with Vaporworx. I promise you that you won't be sorry. Carl is a guy that stands behind his product and gives A1 tech support. I've called him a slew of times when installing his system and got a return call EVERY time. I'm sure many of you are members of other forums, ask around. I have his Vaporworx system in my 69 Camaro.
anyone else learn anything about this that they can share? adapting the OEM LPFP to whatever fuel tank you need seems to be the biggest hurdle?
You do not need to do any of that. Stick a Walbro 255 lph pump into the tank and call it a day. If the engine has some mods excluding turbo/supercharger, then go with a 360 lph and run it a 60 psi. No problem whatsoever. You do need a return though.
Many guys are using the Corvette filter/regulator without problems. I used an Aeromotive regulator and filter mounted near the tank with a return.
You do not need to do any of that. Stick a Walbro 255 lph pump into the tank and call it a day. If the engine has some mods excluding turbo/supercharger, then go with a 360 lph and run it a 60 psi. No problem whatsoever. You do need a return though.
Many guys are using the Corvette filter/regulator without problems. I used an Aeromotive regulator and filter mounted near the tank with a return.
No offense man, but I think going with the setup that the LT4 engine comes with from the factory is the preferred play. PWM is the future of fuel, and it makes a ton of sense to go that route.
No filter, no regulator, no return, no relays. No issues with fuel starvation, no prematurely burned out pumps, it's by far a night and day better setup, which is why GM went with it. Not to mention it's a far cheaper setup
No offense man, but I think going with the setup that the LT4 engine comes with from the factory is the preferred play. PWM is the future of fuel, and it makes a ton of sense to go that route.
No filter, no regulator, no return, no relays. No issues with fuel starvation, no prematurely burned out pumps, it's by far a night and day better setup, which is why GM went with it. Not to mention it's a far cheaper setup
LOL...whatever!. If you are having all the problems you say with the conventional system, you apparently aren't setting it up correctly or buying cheap parts.
LOL...whatever!. If you are having all the problems you say with the conventional system, you apparently aren't setting it up correctly or buying cheap parts.
I haven't set up anything, learning from those who have done it correctly, using the GENV PWM fuel modules. Like I mentioned before, theres a reason GM went to this system, it's easier, cheaper, more reliable, doesn't have all the problems of the return system.
The only issue is finding a in tank fuel module that will work with the tank in your particular vehicle. Ricks Tanks makes tanks designed for the LPFP for a lot of the classic muscle cars, but finding one that will work for my GMT400 is where I'm currently at.
Last edited by theunderlord; Mar 11, 2022 at 01:29 AM.
I haven't set up anything, learning from those who have done it correctly, using the GENV PWM fuel modules. Like I mentioned before, theres a reason GM went to this system, it's easier, cheaper, more reliable, doesn't have all the problems of the return system.
The only issue is finding a in tank fuel module that will work with the tank in your particular vehicle. Ricks Tanks makes tanks designed for the LPFP for a lot of the classic muscle cars, but finding one that will work for my GMT400 is where I'm currently at.
I saw the other day that Tanks inc now sells PWM compatible pumps to go with their fuel injection tanks, was probably gonna be the front runner for my next swap
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LT! gen 5 returnless fuel system 
