Fuel Pump Priming Issues

XofXtimeX

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Hello all,

I came upon an issue that I *think* is in the harness coming from somewhere within the driverside dash, leading to the ignition cylinder. Where you plug in a turbo timer harness. 13 years ago or so, I attempted an alarm install with a remote start. We eventually got the car running and it's been running fine ever since. I imagine we tapped into those wires behind the ignition cylinder for several reasons. These were not well done, and I'd like to remove the system entirely. (Sidebar: anyone have any tips for removing soldered wires? Just heat it up with the iron until it melts off? )

The issue is: With the key in the "ON" position, the fuel pump will start priming with no discernable pattern. ON-OFF-ON for 3 seconds-OFF-ON-OFF for 1-10 seconds- and so on. Sometimes it does this, sometimes it doesn't. I got under there and wiggled each wire individually that's been tapped in to for the alarm, again, no repeatable pattern I could recreate, which gave me no real area of focus. Besides... All of it, I suppose.

I did some digging and found this "The fuel pump turns on after the afm sees a signal." from @hvyman in 2014 in a thread about fuel pump issues which gave me another thought... Could this be in my DET3 Wiring? Or are "on" and "priming" different actions?

My question is: could there be an issue where I was looking in the ignition cylinder wiring, or could it perhaps be with my ECUMaster DET3 wiring? Perhaps it keeps seeing AFM signal over and over again?

Any help would be greatly appreciated.

-Nick
 

figgie

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Hi Nick,

I like to keep things simple.

Remove the Det3 from the picture. Get it as electrically close as possible to the OEM configuration. Try again and report back.
 

XofXtimeX

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@figgie Do you mean to get the car up and running without the piggyback, or simply unplug it, and try the key on and see if the problem persists?
 

XofXtimeX

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That makes sense. Unfortunately, I no longer have an AFM, so I can't do that. It was installed by Zach from ECUMaster in 2014, and has been running fine ever since. I can remove it, but I wouldn't be able to start the car. Are you thinking it's more likely there than in the ignition harness itself?

Thanks so much for your help, @figgie !
 

figgie

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With piggy backs, it just another thing that can fail.

Are there settings in the Det3 that might possibly override the OEM priming function?

I would say even without an AFM, remove the det3 and see if the car primes. Unfortunately not much else to do since the Det3 essentially became the AFM with the removal of the OEM AFM :(
 

XofXtimeX

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With piggy backs, it just another thing that can fail.

Are there settings in the Det3 that might possibly override the OEM priming function?

I would say even without an AFM, remove the det3 and see if the car primes. Unfortunately not much else to do since the Det3 essentially became the AFM with the removal of the OEM AFM :(
Very true. I'm not sure about the settings. I know I haven't changed them since '14, but it's certainly worth a look.

Of course, there are plans to replace with a full stand alone & harness in the future, but that'll have to wait. I can definitely unplug it, and see if the priming condition is present or not. I'll handle that and report back.

Thanks for your help!