Coyote First Start - No Start

[Straversi]

I tried to bring the Coyote to life Saturday but no joy.

Fuel in, battery connected, fluids checked, connections checked, camera rolling....Nada.

Swallow my pride, shut down the camera and try to figure it out.

Key to "on" and we have +12V on the gauge but no sound coming from the fuel pump. I do have fuel in the tank.

I put +12V directly to the fuel pump leads and the pump engages so I know my problem is electrical and not mechanical. Unfortunately, my powered fuel pump reveals a fuel leak so the rest of my energy is spent fixing the leak. I retreat to a glass of wine and my wiring schematics.

I reached out to EdwardB thinking I had tapped into the RF harness incorrectly. He suggested that I check to see if I was getting +12V at the Dk Green Coyote pigtail. I was not.

I'm starting this post to share the experience and not pollute EdwardB's thread with my problems.

I called Ford Racing Techs (Marty and Tom) Monday morning and they steered me towards the same Dk Green lead. Also asked me to check the Lt. Green Ignition trigger lead. I was getting +12V at the Lt Green lead but only +6.1V at the Dk Green lead so they suspect faulty grounds are at play.

Per their suggestions I have (1) checked my grounds (2) re-run the connection from the main Coyote harness ground to the battery ground (3) Run a new Neg battery cable directly to the engine block. Short of driving a steak in the earth, this sucker is as grounded as it gets. Still only getting +6.1V at the Dk Green lead. I have been instructed to call back tomorrow when Ray is in. Apparently Ray is the man for these issues.

The good news is that the engine works. In one of my multimeter checks I turned the key with the clutch switch engaged. The engine fired right up. I forgot I had manually pumped fuel into the system two days prior. Startled? Ya, but what a great sound!

Suggestions?

I'll let you know what Ray the Ford Tech comes up with.

-Steve

[phileas_fogg]

I feel your pain. On my first start attempt, I misconfigured my EFI computer such that it was not telling the coil to spark. Took a couple of days, but I figured out my error.

Is it possible to check continuity between the ends of the dark green wire? That would eliminate the wire itself as the culprit. If possible, you could also check if there's +12V at the input to the dark green wire.


John

[wareaglescott]

Don't have much to offer but have many, many communications with Ray Heron. Good guy. He will get you squared away. Tell him Scott says hi. Haha

[BEAR-AvHistory]

Is the pump in the tank or external?

[Straversi]

In tank fuel pump.

Wires seem to check out fine although skills with multimeter are suspect.

[edwardb]

I'm assuming when you say it "started right up" that was with residual fuel and it died pretty quickly. That EFI setup won't do much without constant pressure. Surprised it started at all without pressure from the fuel pump.

I posted the RF connection info for the fuel pump wiring in my build thread where you asked the question. I assume you saw that. As best I can tell from your pictures, you have it hooked up correctly.

The +12V at the Lt Green lead should be from the RF harness. Not the Coyote PDB. Should only be present with the ignition key on. That's the Ignition Relay Trigger which energizes the Coyote ignition relay and makes the system active. So don't think that's telling you too much about the PDB power.

With the grounds you've described, and I'm assuming equally solid positive wires, if you're still not getting +12V on the Dk Green fuel pump wire with the ignition key on, then seems something internal to the Coyote wiring or PDB. Maybe the fuel pump relay in the Coyote PDB? That one is R4 in the PDB. You could swap it with R5 and see if anything changes. R5 is for A/C and which I'm guessing you aren't using. I'm assuming the fuel pump fuse JC4 is OK since you have some voltage. But if in doubt that too could be swapped. They're J-Case fuses. The layout of what's in the PDB isn't marked on the box, but it's shown on page 21 of the Ford instructions.

Will be curious to hear what Ray says. My experience as well is he's the go-to guy for electrical issues.

[boBQuincy]

Most multimeters are suspect too, with a typical 10 M ohm input impedance they will read voltage even if there is almost no current behind it. 6.1 V sounds suspect, like there may be two devices in series.


In tank fuel pump.

Wires seem to check out fine although skills with multimeter are suspect.

[BEAR-AvHistory]

In tank fuel pump.

Wires seem to check out fine although skills with multimeter are suspect.

FWIW. Mine is external but who knows. Had a similar problem. The wires used were from the RF harness with the plugs cut off to mount to the pump. Problem was solved by loosing the RF ground & running a short separate ground wire from the pump directly to the chassis.

[Straversi]

I'm assuming when you say it "started right up" that was with residual fuel and it died pretty quickly. That EFI setup won't do much without constant pressure. Surprised it started at all without pressure from the fuel pump.

I posted the RF connection info for the fuel pump wiring in my build thread where you asked the question. I assume you saw that. As best I can tell from your pictures, you have it hooked up correctly.

The +12V at the Lt Green lead should be from the RF harness. Not the Coyote PDB. Should only be present with the ignition key on. That's the Ignition Relay Trigger which energizes the Coyote ignition relay and makes the system active. So don't think that's telling you too much about the PDB power.

With the grounds you've described, and I'm assuming equally solid positive wires, if you're still not getting +12V on the Dk Green fuel pump wire with the ignition key on, then seems something internal to the Coyote wiring or PDB. Maybe the fuel pump relay in the Coyote PDB? That one is R4 in the PDB. You could swap it with R5 and see if anything changes. R5 is for A/C and which I'm guessing you aren't using. I'm assuming the fuel pump fuse JC4 is OK since you have some voltage. But if in doubt that too could be swapped. They're J-Case fuses. The layout of what's in the PDB isn't marked on the box, but it's shown on page 21 of the Ford instructions.

Will be curious to hear what Ray says. My experience as well is he's the go-to guy for electrical issues.

Thanks I did see your reply and followed your recommendations on where to start. I swapped the relays and fuses on my own with no change. Called Ray this morning and he asked me to to the same thing. Tested the fuses. Tested the harness side of the pigtail connection. Did several tests to the PDB with a jumper wire that I won't try to describe. Finally, Ray emailed his go-to wiring guy and they told me to ship them my PCM.
I'll report what they find.
Yes, the accidental start was short lived. I keyed it off after a couple of glorious seconds. Glad it did run because that told Ray quite a bit and eliminated a few potential faults.

[edwardb]

Sorry to hear it wasn't a quick/easy fix. But sounds like you're getting good support from Ford.