3V to Coyote; Return or Returnless-ish?

mattjames

Member
Joined
Dec 16, 2013
Posts
125
Reaction score
63
I'm still in the planning stages of swapping my 07 GT to a Coyote. I've had all the mechanical parts to do it over a year now.

I've been spending hours the past couple weeks studying both car's wiring diagrams.
My question is, if I wire the FPDM to Coyote PCM like factory, do I need the Coyote FPDM, or would the 4.6 FDPM work with the Coyote PCM? The wires are labeled the same from 4.6 to 5.0, just at different pin locations.

I've already have the corvette fuel filter, fittings, etc to make it a return style since I originally planned to just do a return system and make it match in the tune, but if the 4.6 FPDM will work with the Coyote PCM ( or if the 11-14 plugs in, bonus, [EDIT: the connectors are labeled the same number but pins are different :/ ] ) I'll just make a new feed line from the stock filter to the Coyote rail and keep it returnless.
 
Last edited:

JEWC_Motorsports

S197 Junkie
S197 Team Member
Joined
Aug 22, 2010
Posts
20,471
Reaction score
1,596
Location
Texas
If you ever decide to go boosted you will want a return system. Id do it now while its apart.
 

Dino Dino Bambino

I have a red car
Joined
Aug 11, 2014
Posts
3,880
Reaction score
1,751
Location
Cyprus
If you're going to keep the Coyote N/A, keeping the fuel system returnless will be fine but if you're planning to boost it anytime in the future, it's better to convert it to a return style system from now and save yourself a lot of hassle later on.
 

Juice

forum member
Joined
Aug 24, 2017
Posts
4,622
Reaction score
1,904
I am running the stock v6 fuel system, untouched. Just bought the fuel and vapor lines from the hard lines to engine, for a coyote. Ppl like to go overboard with fuel supply when it is totally unnecessary.
 

mattjames

Member
Joined
Dec 16, 2013
Posts
125
Reaction score
63
I am running the stock v6 fuel system, untouched. Just bought the fuel and vapor lines from the hard lines to engine, for a coyote. Ppl like to go overboard with fuel supply when it is totally unnecessary.
So the 4.0 FDPM (guessing the 4.6 is the same) worked with the Coyote PCM??
If you're going to keep the Coyote N/A, keeping the fuel system returnless will be fine but if you're planning to boost it anytime in the future, it's better to convert it to a return style system from now and save yourself a lot of hassle later on.

For now the engine is a stage 3 cammed first gen that probably won’t see boost very soon
 

Juice

forum member
Joined
Aug 24, 2017
Posts
4,622
Reaction score
1,904
Yes, the 4.0 and 4.6 fuel system is the same based on my research. I only worked on the swap under the hood and dash. Never touched the tank or lines. (Except new stock fuel filter). Just hooked up the 2 circuits at the pcm. Fuel pump control and monitor, IIRC. It works 100% without issues and makes 400 at the wheels.
 

OvalSports

Member
Joined
Apr 6, 2021
Posts
54
Reaction score
14
Location
Florida
I purchased the Power By the Hour electrical set up, and was told return style was a must with this configuration.
We ran the return line and are getting ready to finish the plumbing. Is there any need to change the pump, or will running the 4.0 stock pump work with a factory boss engine?
 

mattjames

Member
Joined
Dec 16, 2013
Posts
125
Reaction score
63
I purchased the Power By the Hour electrical set up, and was told return style was a must with this configuration.
We ran the return line and are getting ready to finish the plumbing. Is there any need to change the pump, or will running the 4.0 stock pump work with a factory boss engine?
Probably because their harness has the fuel pump always running 100% duty cycle
 

mattjames

Member
Joined
Dec 16, 2013
Posts
125
Reaction score
63
I purchased the Power By the Hour electrical set up, and was told return style was a must with this configuration.
We ran the return line and are getting ready to finish the plumbing. Is there any need to change the pump, or will running the 4.0 stock pump work with a factory boss engine?
NA coyote requires a 155LPH pump minimum. Idk about Boss
 

Dino Dino Bambino

I have a red car
Joined
Aug 11, 2014
Posts
3,880
Reaction score
1,751
Location
Cyprus
The stock v6 setup is plenty to feed it. ;)

What's the V6 pump rated at? I know the 3V GT pump is rated at 148lph (238lb/hr) which is enough to support about 530 N/A crank HP (470rwhp) or 430 boosted crank HP (380rwhp). Since boosted 3Vs produce more than 380rwhp, a BAP is required to increase the voltage to the pump. A N/A Coyote would be fine on the stock 3V pump even with bolt ons (CAI, LT headers, '18+ intake manifold).
 
Last edited:

Jack F

Member
Joined
Apr 26, 2021
Posts
112
Reaction score
50
Just upgrade to a higher lph pump. Forget that 90s bullshit "boost-a-pump". It's right under the left side of the rear seat bottom.
 

Juice

forum member
Joined
Aug 24, 2017
Posts
4,622
Reaction score
1,904
No, leave the stock pump, it is plenty. Forget that 90s bs of over specking fuel pumps. If by some strange reason is not enough, the CEL will let you know.
V6 pump is same as GT, as far as I know. I already said that.
 

mattjames

Member
Joined
Dec 16, 2013
Posts
125
Reaction score
63
Well the stock pump was never in question. I already have a 340 DW replacement ready that will be used. Engine going in made 489Whp on corn so I’m definitely not using the stock pump since it’ll also have 47lb inj as well. And since the 3V FDPM works itll most likely stay returnless
 

OX1

forum member
Joined
Sep 20, 2015
Posts
528
Reaction score
185
Location
Jackson, NJ
If you're going to keep the Coyote N/A, keeping the fuel system returnless will be fine but if you're planning to boost it anytime in the future, it's better to convert it to a return style system from now and save yourself a lot of hassle later on.

Like what hassle? I only have 7K on Roush boost-a-pump and 47's, but no issues as of yet, trapping what you see below.
 

Dino Dino Bambino

I have a red car
Joined
Aug 11, 2014
Posts
3,880
Reaction score
1,751
Location
Cyprus
Like what hassle? I only have 7K on Roush boost-a-pump and 47's, but no issues as of yet, trapping what you see below.

The hassle of tearing the fuel system apart again later on if he decides to boost his Coyote swapped 3V S197 in order to convert the fuel system to a return style. It depends on what power level he's after. I'm guessing you're somewhere in the 550-600rwhp range which is still OK on a stock returnless system with a BAP.
 

OX1

forum member
Joined
Sep 20, 2015
Posts
528
Reaction score
185
Location
Jackson, NJ
The hassle of tearing the fuel system apart again later on if he decides to boost his Coyote swapped 3V S197 in order to convert the fuel system to a return style. It depends on what power level he's after. I'm guessing you're somewhere in the 550-600rwhp range which is still OK on a stock returnless system with a BAP.

Thanks for the clarification. Guess it really depends on how easy it is, with the car ripped apart already.
 

mattjames

Member
Joined
Dec 16, 2013
Posts
125
Reaction score
63
I'm still a bit on the fence. If I'm replacing the pump anyway, it's just a bulkhead, a drilled hole, and a line away from being return. Not to mention, I already have those pieces ready.
 

Juice

forum member
Joined
Aug 24, 2017
Posts
4,622
Reaction score
1,904
As far as I know, the main reason for return style system on boosted cars is the huge spike in fuel pressure when comming off boost. Pump takes a split second to adjust. You dont even 'need' to change anything in the tune. For return style, the pressure is just fixed in the tune vs varying the pressure for returnless. The variation is less than 3 psi from what I remember. My tune was set to return style, and ran returnless fine. But idle and low loads, pcm was pulling 10% fuel to compensate.
 

Laga

Senior Member
Joined
Aug 10, 2019
Posts
991
Reaction score
518
Location
Chicago
A return style system also lowers the temperature of the fuel. Which can help reduce the chances of detonation and vapor lock.
 

Latest posts

Support us!

Support Us - Become A Supporting Member Today!

Click Here For Details

Sponsor Links

Banner image
Back
Top