Fuel PSI not increasing with boost after E85 conv

[ronnie justice]

Recently converted to e85. Turbo tweak 95lb injectors and chip. Have a steady 43psi fuel at idle vac unplugged. The problem is under boost (20lbs) my fuel psi is only getting up to about 50-53psi. My AF is leaning way out. The car misses and backfires under full boost. I’m running a new DW300 pump with Hotwire. Stock lines. Any ideas? All research says stock lines will support 95lb injectors. With the slight exception being the return line restriction which would cause a spike in pressure which is not my problem.

 

[mblum]

I don't see any mention of modifications to the car, that would be helpful? Depending on how mild or wild your setup is and how much power your trying to make that pump may not be enough. Example, if the car is relatively stock with "bolt-on's" that pump should do, if you have ported heads, roller cam, full bolt-ons ect, that pump probably won't supply enough flow.

I'd strongly suggest staying out of full boost until you get this resolved or a set of head gaskets or worse could be needed. Is the car showing KR?

How new is the fuel filter?

Are you able to log fuel pressure and AFR? If so, back the boost down low and see if you get a 1:1 rise. If so, slowly increase the boost until you no longer see a 1:1 rise and AFR starts to drop off. Do this slowly 1-2 psi at a time and monitor for KR.

 

[Chuck Leeper]

All research says stock lines will support 95lb injectors.

Burning gas.... What will they do with a 30+% increase in demand?

 

[xlr8ngn]

To diagnose fuel capacity problems, monitor your fuel pressure as close to the pump as possible. If the fuel pressure rises with boost and then begins to drop off, you are running out of pump. If it rises with boost and flattens out, you have a fuel line or delivery issue. If it rises normally with boost and does not flatline or drop off, you likely have no fuel system problem.

 

[BEATAV8]

The DW300 will need some premium wiring and a volt booster to support 80lb injectors. 95lb probably not going to make it....
BCWA-BLT1 Racetronix BLT1 Bulkhead Wiring Assy HD Tyco
FPWH-076 Racetronix BLT1 Fuel Pump Wiring Harness HD. Alternate P/N FPWH-018
https://www.racetronix.biz/p/blt1-fuel-pump-wiring-harness-hd/fpwh-018
https://www.racetronix.biz/p/blt1-bulkhead-wiring-assembly-hd-tyco/bcwa-blt1

10ga ground wire from racetronix ground bundle to battery up front. Home made.

Most folks don't replace the bulkhead wiring. But it's critical to do so.

By the time you wire it all up like this, it's probably gonna over flow the return line. At that point your just better off using new -8/-6 lines and a hellcat pump instead.

 

[dynoman]

Also double check the short hose inside the tank from the pump for any leaks / cracks .

 

[JayC]

Sounds like you dont have enough pump.

 

[ronnie justice]

I don't see any mention of modifications to the car, that would be helpful? Depending on how mild or wild your setup is and how much power your trying to make that pump may not be enough. Example, if the car is relatively stock with "bolt-on's" that pump should do, if you have ported heads, roller cam, full bolt-ons ect, that pump probably won't supply enough flow.

I'd strongly suggest staying out of full boost until you get this resolved or a set of head gaskets or worse could be needed. Is the car showing KR?

How new is the fuel filter?

Are you able to log fuel pressure and AFR? If so, back the boost down low and see if you get a 1:1 rise. If so, slowly increase the boost until you no longer see a 1:1 rise and AFR starts to drop off. Do this slowly 1-2 psi at a time and monitor for KR.

Thanks for responding. I have ported stock heads, big valves, ported stock intake, and roller cam. Fuel filter is 10yrs old with maybe 10k miles on it.

I show 0 KR. Even when it breaks up and backfires. I do have a wideband and Fuel psi gauges in the car. I will back down the boost like you said.

Before this current set up I was running 42lb injectors with a red Armstrong pump. I was building adequate fuel psi then. Same boost 20lbs

 

[Chuck Leeper]

Fuel filter is 10yrs old with maybe 10k miles on it.

 

[JayC]

You may also not have enough line. You have to keep in mind how much fuel those injectors dump every time they fire. Back in the day, mid to high 10s was where you started re-evaluating your fuel system from a lines perspective.

 

[dynoman]

That E85 WILL clean your tank & lines and send it to the filter .............. Change the filter before doing anything else and maybe upgrade to a better filter .

 

[BEATAV8]

Thanks for responding. I have ported stock heads, big valves, ported stock intake, and roller cam. Fuel filter is 10yrs old with maybe 10k miles on it.

I show 0 KR. Even when it breaks up and backfires. I do have a wideband and Fuel psi gauges in the car. I will back down the boost like you said.

Before this current set up I was running 42lb injectors with a red Armstrong pump. I was building adequate fuel psi then. Same boost 20lbs

You've got plenty enough there to justify 120lb injectors, 525L/hr pump, and larger fuel lines.

 

[Chuck Leeper]

The stock line controversy....
Many yrs ago in a town far far away, a "guru" argued that the stock line/filter system would support 1000FWHP!.
Haven't seen him in yrs.

 

[ronnie justice]

I don't see any mention of modifications to the car, that would be helpful? Depending on how mild or wild your setup is and how much power your trying to make that pump may not be enough. Example, if the car is relatively stock with "bolt-on's" that pump should do, if you have ported heads, roller cam, full bolt-ons ect, that pump probably won't supply enough flow.

I'd strongly suggest staying out of full boost until you get this resolved or a set of head gaskets or worse could be needed. Is the car showing KR?

How new is the fuel filter?

Are you able to log fuel pressure and AFR? If so, back the boost down low and see if you get a 1:1 rise. If so, slowly increase the boost until you no longer see a 1:1 rise and AFR starts to drop off. Do this slowly 1-2 psi at a time and monitor for KR.

I backed boost off to 16 pounds. Pump still only builds about 52psi of fuel psi but it doesn’t break up as bad. 52psi is still 7psi short of adequate. I’m ordering the hellcat pump and lines.

 

[Chuck Leeper]

That 10yo filter may not be E85 friendly and has come "unglued" so to speak.
The alky will dissolve the glue in the filter media and the remaining fibers will be found it the inj filter baskets.
Just tried to resurrect a set of 220's that suffered that fate.
The failure cost the owner a $25K engine.
Shitcan the stock filter and put one in that'll TCOB.

 

[ronnie justice]

I have a new Wix replacement ready to go on

 

[Chuck Leeper]

I have a new Wix replacement ready to go on

If it's a stock type that goes in line, it's no better than what u take off... Other than it's clean.
If you put the big pump on, then what?

 

[ronnie justice]

Is this a legit question or do you have a better suggestion? A specific filter?

 

[ronnie justice]

Everything I’ve researched said there’s no issue with stock filter and e85

 

[ronnie justice]

I’m open to suggestions for a high flow e85 safe, stick location filter