Holley EFI dominator cutting off after start.

SpoolingTurbo6

SpoolingTurbo6

Donating Member
Installed a Holley EFI dominator on a Syclone.
The engine will start, run, then stop.. Almost like the coil wire is pulled. It will not fire again until the system / key is cycled. Sometimes having to disconnect and reconnect the efi power completely before the fuel pump will cycle on again. (this has happened twice)

The coil has 12v on the pink wire before, during and after cranking.

Red/white wire has 12v before, during and after cranking.

Cloned my working tune over from my Typhoon. Few changes. From Ty to Sy. And updated the firmware, and software to v4.0
1. Injectors ( turbotime 75 #) low impedance. (2.4ohms)
2. RaceTronix hot wire kit.
3. Holley fuel pump relay powers firewall relay, powers RaceTronix

Other than injectors, I shouldn't need to change anything in the setup to run the Syclone motor.
I set them as low impedance, 73psi, 60lb flow rate,

Anyone had a similar issue?
Thanks
Tyson
 
RealFastV6

RealFastV6

@jb_and_his_coffee
Re: Holley EFI dominator cutting off after start.

I'm just going to throw this out there but are you sure it's getting enough fuel in your starting parameters? The cranking fuel is probably setup for Pulse Width so if you changed the injectors between the two tunes you need to adjust it.
 
randy merritt

randy merritt

Donating Member
Re: Holley EFI dominator cutting off after start.

I am wondering if it might have something to do with the oil pressure/fuel pump circuit. I think you removed a bunch of the wiring from the driver's firewall area. Try running the Holley fuel pump power wire directly to the trigger terminal on the RaceTronix relay.
 
SpoolingTurbo6

SpoolingTurbo6

Donating Member
Re: Holley EFI dominator cutting off after start.

We ran the pump constantly during cranking and startup. It had no effect on the situation.
 
SpoolingTurbo6

SpoolingTurbo6

Donating Member
Re: Holley EFI dominator cutting off after start.

Justin. I'm not sure of anything.
I did input the injectors size, rate, flow number into the holley, as I said in the last paragraph. I thought it would make all the necessary adjustments to run the engine.
 
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D

denny

Active member
Re: Holley EFI dominator cutting off after start.

Can't you log it and look at the log to see what signal is dropping off the ecu?
Maybe ecu not seeing crank or cam signal or oil pressure.
 
SpoolingTurbo6

SpoolingTurbo6

Donating Member
Re: Holley EFI dominator cutting off after start.

Eric, yes. I meant to type low z. At first the flow was 43.
It didn't seem to make a diff at 43 or 60 lbs.
 
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SpoolingTurbo6

SpoolingTurbo6

Donating Member
Re: Holley EFI dominator cutting off after start.

Im curious why the ecm doesn't kick on the pump every time the key is cycling. Sometime I have to pull the fuse before it acts normal.
 
RealFastV6

RealFastV6

@jb_and_his_coffee
SpoolingTurbo6 said:
Im curious why the ecm doesn't kick on the pump every time the key is cycling. Sometime I have to pull the fuse before it acts normal.
Click to expand...


Post a vid, but my bet is...

Once you go over Cranking RPM into running RPM the ECU won't re prime the pump without turning the key all the way off (and waiting for the ECU to shut down). That's normal. You'd normally never notice this but you've got your fueling wrong so the truck is trying to start and stumbling all over itself and going over the Running RPM in the process but doesn't have the fueling to stay running.



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SpoolingTurbo6

SpoolingTurbo6

Donating Member
Re: Holley EFI dominator cutting off after start.

I measured the resistance on the injectors and it is 2.4 ohms. I do know that they are 75 pound injectors and engraved on them is an average of 73 PSI. I have unhooked all other possible sensors and tried to set the TPS. I have check for continuity on all three wires of the TPS to the ECM side P1 connector. They are showing that there are no breaks in the wires. Also triple checked my wiring to the TPS it is correct. I am still unable to get the TPS to set.


Any ideas?
 
SpoolingTurbo6

SpoolingTurbo6

Donating Member
Re: Holley EFI dominator cutting off after start.

I took the ecm out of the syclone. And installed it into the typhoon which has the exact same harness. And tried to set the TPS on the typhoon. It failed to autoset in the typhoon also.

It may be a bad unit. I don't know.
 
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RealFastV6

RealFastV6

@jb_and_his_coffee
When you say unit; are you talking about the TPS sensor or the ECU?


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RealFastV6

RealFastV6

@jb_and_his_coffee
No but if you don't have TPS then you're not going to be able to start it.


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