Problem with FAST XFI.

[Turbopoul]

Been having this problem ever since i bought FAST XFI. FAST tech are stumped.

At 40% and above go pedal, the engine check light comes on, saying that injectors dutycycle is at 100%.
Injectors are #85, fuel pump is A1000.
The base fuel 43psi. Psi goes up with boost, 1psi= 1psi boost.
Afr is at 11.5-11.8 under boost.

I have no idea what else to do ??

Please help

 

[Otto J]

Can you send me a datalog and your current gct file to look at?
How new is the fuel pump? what are you using for filters before and after pump?

 

[Turbopoul]

Hey Otto J , pump, before and after filters are brand new Aeromotive.
I was wondering, if AFR set 11.5-11.8 , and VE tables set to low, under 90, could be the problem ?
email sent. Thanks..

 

[Otto J]

Poul,after looking at that log you need to take a serious look at your fuel system to before going any further.
what does your fuel system consist of?

 

[Turbopoul]

Otto J , I have rear sump with 10an fitting , Aeromotive A1000 pump, before and after Aeromotive filters, 8an braded line from filter to stock fuel rail, GN boost refrence reg, stock 3/8 return line, stock vent (open at engine bay)

The fuel psi goes up with boost, base 43psi, 20psi boost = 63psi on the fuel gauge.

Can the tune be way off ?

Thanks.

 

[Otto J]

Dont hesitate to remove both filters and have a look at them.
just because the pressure isnt dropping of doesnt mean that flow isnt.
doesnt matter if they are new or not.
Is the before filter a steel screen or paper?

 

[asloan5]

did you clean the braided line after you installed the ends ? as shipped they are not very clean and have enough crap in them to clog up the little screens in the fuel injectors.

 

[bobc455]

Is your fuel filter visible while driving? Or is it underhood? (as long as pressure is not dropping, your pump is able to handle whatever flow the injectors are requesting.)

Do you have any O2 correction?

Does a datalog agree that the injectors are trying for 100%?

Does this occur at all RPM?

Is your air and water temperature indication accurate?

Have you had your injectors cleaned and flow-tested recently?

Is your fuel pump as low as possible on the vehicle?

Any knock?

-BC

 

[HighPSI]

If your fuel pressure is keeping up and the injectors are reading 100% duty cycle, you either need a larger injector or have a fuel delivery problem. This is provided you are running at the proper A/F ratio. Have you tried raising the base fuel pressure up? Even if the tune was way off, the duty cylce wouldn't change as long as the WBO2 was mainting the proper A/F ratio.

 

[Turbopoul]

Hey guys, I instaled a brand new fuel tank, cleaned the braded line before XFI.
I raised fuel psi to 50 base, no change.
WB correction is 24%.
One thing, I'm running 10g wire from alt to pump relay by the pump, I had to rig the relay so that it turns the pump on with the ground wire that i am running back to the XFI. I noticed that the ground wire is only 16g, and original from 1992.
Wonder if that could be the problem ? I'm going to replace it with new 12g, see if it helps.

 

[Otto J]

Hey guys, I instaled a brand new fuel tank, cleaned the braded line before XFI.
I raised fuel psi to 50 base, no change.
WB correction is 24%.
One thing, I'm running 10g wire from alt to pump relay by the pump, I had to rig the relay so that it turns the pump on with the ground wire that i am running back to the XFI. I noticed that the ground wire is only 16g, and original from 1992.
Wonder if that could be the problem ? I'm going to replace it with new 12g, see if it helps.

from what i saw the o2 correction wasnt near that.is this a new problem?
What is the PRE filter made of in your fuel system?
That neg trigger is fine,if its working it triggers,its just a signal wire.

 

[bobc455]

I noticed that the ground wire is only 16g, and original from 1992. Wonder if that could be the problem ?

If your fuel pressure is not dropping at WOT, then the wiring is not the problem.

Can you observe your fuel pressure while driving? Is it dropping at WOT?

-Bob C.

 

[Turbopoul]

Hey Otto J, look at the 3.65 sec frame 73 of the log, XFI is adding 21.9%

Both filters (before and after the pump are Aeromotive, I think they are paper element)

I have an Autometer fuel gauge that i watch while driving, It reads 43psi base and 1psi=1psi boost, 15 psi boost = 58 psi on the gauge.

One thing: I'm using wire from stock wg relay to turn on + injectors, wonder if its dropping voltage while on boost ? (using after market boost controler)

 

[DR BOOST]

i had a paper element filter collapse causing the same scenario. pop out the elements and take it for a spin.

 

[Otto J]

Hey Otto J, look at the 3.65 sec frame 73 of the log, XFI is adding 21.9%

Both filters (before and after the pump are Aeromotive, I think they are paper element)

I have an Autometer fuel gauge that i watch while driving, It reads 43psi base and 1psi=1psi boost, 15 psi boost = 58 psi on the gauge.

One thing: I'm using wire from stock wg relay to turn on + injectors, wonder if its dropping voltage while on boost ? (using after market boost controler)

If you have a paper elemeent between the tank and pump get it out of there,it should be stainless mesh screen there,paper is fine AFTER the pump,This could be your problem,next what are you using for a relay to turn the pump on?
The aeromotive pumps do not like the little 30 amp light relays most people use,If so get that out of there and use a continuous duty
starter type relay.
The spot that you see adding the 21.9 is transistion fuel,it just needs to be played with,has nothing to do with fuel delivery,if you look at the correction even at 100% duty cycle it is only 1.6 or so.
take the paper element out and go make a pass(as long as you trust your fuel and tank are clean) and see what happens,also let me know what you run for a relay

 

[Otto J]

Do yourself a favor and buy a Caspers injector hotwire harness,this is standard issue on ANY car I work on,This alone will drop injecotr duty cycle a min of 10% on any car using stock wiring

 

[HighPSI]

I'm pretty sure he is using a Casper adaptor harness. If so, they have a new injector harness built into them since the Sy/Ty's were wired batch fire from the factory.

 

[Turbopoul]

I'm using racetronix hotwire fuel pump kit, it has 40amp relay that i had to modify so that i can use XFI neg fuel pump port.

The fuel filters are clean, and it flows ALOT of fuel.

One thing, I had alot of problems with caspers "plug and play" harness. It would plug but would NOT play. Could not get injectors to fire. Finnaly i cut oem plugs, and one by one ran the wires to the XFI. I'm still using caspers injectors and adapter harness to the "D" connector on XFI. I wonder if the firing order on the that harness is correct ?
Are Typhoon wiring for the injectors and adapter harness to the "D" connector the same as GN ?

 

[HighPSI]

Yes, same firing order. Even if it was wrong, it wouldn't matter at 100% duty cycle. At that point their no longer pulsing, just nozzles.

 

[Otto J]

Are you DAMN sure you have the proper injectors? Did you recheck the part number on the Injector?
Also get that paper element out of the pre filter
it may cause a lean out at higher pressures even though it appears to flow well