View Full Version : Coyote New battery- no fire
legend42
10-24-2025, 12:22 PM
I replaced a 5 year old battery in my Coyote Gen 3. Engine turns over fine, but no fire. This is what I have checked so far:
1. Fuel pump fuse at RF fuse panel-good.
2. Confirmed fuel pump is working by connecting battery directly to Walbro 190 lph In-tank pump connection.
3. Double checked fuse panel ground.
4. Every thing else electrical in the car seems to be working-gauges, ignition, lights
Car was running and starting fine until the original battery went dead, and I replaced it.
Any suggestions or help appreciated.
AC Bill
10-24-2025, 12:34 PM
Have you checked for spark?
Indy Shu
10-24-2025, 12:38 PM
Does the fuel pump come on when you first turn the key?
If you have a gauge at your regulator does it show pressure?
Have you checked that no blown fuses in the control pack fuse box? I somehow blew one once during the build and it would turn but no spark. I think it was F5 or F6.
legend42
10-24-2025, 01:50 PM
It does appear to have no spark. I do not have fuel pressure guage, and all the control pack fuses look to be good. I probably need my wife to turn the key while I place my hand on the pump connection, I have a in-tank fuel pump.
Indy Shu
10-24-2025, 02:06 PM
You should be able to hear the pump for a couple of seconds when you first turn the key to the on position. If you want to listen again you have to wait 10 or 15 seconds for things to reset.
JeffP
10-24-2025, 04:37 PM
Inertia switch?
legend42
10-24-2025, 05:18 PM
How do you check the Inertia switch? Continuity?
JeffP
10-24-2025, 07:57 PM
How do you check the Inertia switch? Continuity?
That or you should hear your fuel pump running when you first turn the key on, if you do the switch is fine. If you don't, it could be the issue. Make sure the button is pushed down.
Mike.Bray
10-25-2025, 09:03 AM
My money is on no spark. Get one of these to test with. https://www.amazon.com/dp/B01HU2L1NU?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
AC Bill
10-25-2025, 01:56 PM
So a dead battery...changed the battery, now it won't fire. Couple thoughts..
-Prior to changing the battery, did you try jump starting the dead battery to start it? A voltage spike has the potential to cause various electrical issues, including the ECM (ECU, or whatever they call it in the coyote system)..
-If you were switching the ignition key on and off several times, is there is a chance the switch itself has failed. You mention you have ignition in your first post, but how was that confirmed?
No spark could be reflective of a bad crank or cam sensor.
-Injector system failure.
-Bad ground.
I'm curious: did you resolve the problem? What was the cause? Thanks!