DW400 Fuel Pressure Dropping During WOT - Whipple Stage 2

[Face]

Hey guys-

So I've been chasing this problem for a little while now and I can't seem to find out what's going on. Recently wrapped up install of a Stg 2 Whipple on a 2019 and fired off the first few logs where we encountered a steep drop of Fuel Pressure at the pump under WOT. Fearing a bad pump, we replaced it with a brand new DW400 to no avail- logs looked nearly identical.

Lund said he's seen problems/issues with the venturi tube causing a similar bleed off so we yanked the pump, installed fresh lines and the problem persists. I'm getting ready to pull my hair out over here but before I do (and before I dump money into a return style system) I wanted to see if anyone had any suggestions.

Thanks in advance!

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[engineermike]

What pulley are you running? What is the air temp?

 

[Face]

What pulley are you running? What is the air temp?

The car is running the 3.8 pulley that is included with the Stage 2 kit and the dyno room temp is around 75ish degrees.

 

[LSchicago]

Buy a fuel system. DW400 is questionable for a boosted car.

 

[WildHorse]

E85?
edit: can't be cause lund tells you to buy a return style fuel system.

 

[engineermike]

I found the dw400 wouldn’t keep up with a stock stage 2 kit running a 3.75 pulley in cold air. I installed a boost-a-pump and now it’s a solid 73 psi at 7500 rpm running the 3.625 pulley.

it’s beyond me how the roush cars get away at all with the stock pump.

If the pump is mounted too low in the basket it can smoosh the sock flat and restrict flow. That might be something to check.

 

[Face]

Buy a fuel system. DW400 is questionable for a boosted car.

While I appreciate your opinion and partially agree, there is certainly something going on here with this setup in particular. Lund has told me the only time he's seen one drop this bad is when there is an issue with the venturi tube- but since we addressed that (with no luck) I'm just seeing if anyone has any other suggestions.

Fuel system is sounding better and better by the day lol.

 

[Face]

E85?

93 with a splash of Octanium for the dyno.

 

[Face]

I found the dw400 wouldn’t keep up with a stock stage 2 kit running a 3.75 pulley in cold air. I installed a boost-a-pump and now it’s a solid 73 psi at 7500 rpm running the 3.625 pulley.

it’s beyond me how the roush cars get away at all with the stock pump.

If the pump is mounted too low in the basket it can smoosh the sock flat and restrict flow. That might be something to check.

I appreciate the response Mike, I'll give it a look.

 

[WildHorse]

93 with a splash of Octanium for the dyno.

Hmmm. I personally can't see 2 faulty DW400 pumps in a row. What happens with the stock pump ?

 

[TEXAS HEAT]

I appreciate the response Mike, I'll give it a look.

I'm having a similar problem on my centri-boosted 2019, however I am still on the stock pump but with a BAP. My lift pump fuel pressure drops to about 52-55psi on 93. I waiting on the DW400 pump to arrive and install to see if it solves my issues. If not, I'll run the BAP with the DW400 as Engineer Mike has suggested.

Out of curiosity, are you seeing any codes associated with this issue? I'm getting two codes that I clear but they always return. A P2BEE (Bank 2) and P2BEC (Bank 1) which are fuel system (A) too lean. The car runs fine otherwise, STFT's are good as is afr's. Fuel pressure drops to 40psi on the hit, then recovers and drops again as rpm's climb.

 

[19BULLITTwhipple]

Are you having any startup issues? I have the stage 2 Whipple kit with the DW 400. The fuel pump works for me during wot and normal driving. But Lund told me there was no check valve so the car starts and sometime it shuts off before I have to try and start it again.

 

[engineermike]

Not long after the gen3 kits were released, Whipple switched to the dw400 with a check valve. This fixed the hot start issue.

 

[Vert]

Hmmmm, I'm going to have to check mine now. I've been lazy and haven't done a log since I did one when I installed my whipple stg2.

 

[olaosunt]

Hey guys-

So I've been chasing this problem for a little while now and I can't seem to find out what's going on. Recently wrapped up install of a Stg 2 Whipple on a 2019 and fired off the first few logs where we encountered a steep drop of Fuel Pressure at the pump under WOT. Fearing a bad pump, we replaced it with a brand new DW400 to no avail- logs looked nearly identical.

Lund said he's seen problems/issues with the venturi tube causing a similar bleed off so we yanked the pump, installed fresh lines and the problem persists. I'm getting ready to pull my hair out over here but before I do (and before I dump money into a return style system) I wanted to see if anyone had any suggestions.

Thanks in advance!

Well since you already pulled the pumps I assumed checked all the hoses ?
Same thing happened to me before i went return.
Here is what I found . Black rubber feed hose was leaking .

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