2004 Nomad FI won't start

rt66john · 04-24-2023, 04:06 PM

Hello Everyone,
I have a no-start issue with my 2004 Nomad 1500 FI.

Last November, the bike wouldn’t start. A friend (Mercedes tech) and I diagnosed coils as the issue; no voltage at plug wires. I let it sit over the winter as Chicago winters can get darn cold.

I’ve installed new coils. It ran on throttle body cleaner, but not fuel in tank.

My friend brought over a FI tester and the engine ran using it. Put the tank back on and tested the fuel pump. The pressure spiked up to 70 psi on initial key turn. After that test, we installed the tank and the bike started. I rode it around my neighborhood for about 15 minutes, including up to about 70 mph. It seemed to run normally. Started and shut off several times in the garage after the ride. It started every time.
The next day, it wouldn’t start. Not with the fuel in the tank, not with throttle body cleaner sprayed, not with the tank off and the FI tester hooked up. It’s been that way ever since.

The only code the ECU stored is 45, fuel pump, but tank was off. No codes with tank installed.

I replaced all 4 plugs (0.035” gap) and there is fresh fuel in the tank.

The fuel pump primes. After attempts at starting, the plugs are wet with fuel.
There’s spark at all 4 plugs (removed from head, grounded to engine and visually verified). We also tested with a MAC Tools ET2010 scope. There are 10K-15K Volts at each plug.

DFI fuse is fine. According to the parts store, the battery load tests fine. It will not start when jumped from a non-running car.
Doesn’t matter if the clutch lever is squeezed. Doesn’t matter if kickstand is up or down. All attempted startups have been with the transmission in neutral.

It does appear the resistor in the ignition switch has failed. The grey wire at the ECU sees 12V. My friend brought over a little box that can adjust resistance. Set box resistance until we saw 6.6V at the grey wire. Still no start. Is 6.6V low enough? I’m not sure how this works, though. I still get spark when I try to start the engine. Will it allow a few turns, then stop the ignition and/or fuel? I did buy a 100 OHM, .5-Watt resistor I will splice into that grey wire.

When attempting to start, it will often “belch” burning fuel through the throttle body. If I take one plug out of a head, it will throw a flame through the open plug hole.

I’m at a loss now and beginning to think my ECU has gone south.

Any help is appreciated.

Mechaniac · 04-24-2023, 04:17 PM

Test compression. If compression is good and you have spark disconnect the exhaust pipes or muffler if separatable and retry starting.

rt66john · 05-19-2023, 04:26 PM

Compression results on a cold engine: 120psi front, 130psi rear. That's well above the "useable" range listed in the book.

Seems to be plenty of air exiting the mufflers when I try to start it, so I doubt there's a blockage in the exhaust system. It is the stock exhaust.

Quote:

Originally Posted by Mechaniac

Test compression. If compression is good and you have spark disconnect the exhaust pipes or muffler if separatable and retry starting.

04-24-2023, 04:06 PM	#1
rt66john Jr. Member Join Date: Sep 2019 Location: NE IL Posts: 4	2004 Nomad FI won't start Hello Everyone, I have a no-start issue with my 2004 Nomad 1500 FI. Last November, the bike wouldn’t start. A friend (Mercedes tech) and I diagnosed coils as the issue; no voltage at plug wires. I let it sit over the winter as Chicago winters can get darn cold. I’ve installed new coils. It ran on throttle body cleaner, but not fuel in tank. My friend brought over a FI tester and the engine ran using it. Put the tank back on and tested the fuel pump. The pressure spiked up to 70 psi on initial key turn. After that test, we installed the tank and the bike started. I rode it around my neighborhood for about 15 minutes, including up to about 70 mph. It seemed to run normally. Started and shut off several times in the garage after the ride. It started every time. The next day, it wouldn’t start. Not with the fuel in the tank, not with throttle body cleaner sprayed, not with the tank off and the FI tester hooked up. It’s been that way ever since. The only code the ECU stored is 45, fuel pump, but tank was off. No codes with tank installed. I replaced all 4 plugs (0.035” gap) and there is fresh fuel in the tank. The fuel pump primes. After attempts at starting, the plugs are wet with fuel. There’s spark at all 4 plugs (removed from head, grounded to engine and visually verified). We also tested with a MAC Tools ET2010 scope. There are 10K-15K Volts at each plug. DFI fuse is fine. According to the parts store, the battery load tests fine. It will not start when jumped from a non-running car. Doesn’t matter if the clutch lever is squeezed. Doesn’t matter if kickstand is up or down. All attempted startups have been with the transmission in neutral. It does appear the resistor in the ignition switch has failed. The grey wire at the ECU sees 12V. My friend brought over a little box that can adjust resistance. Set box resistance until we saw 6.6V at the grey wire. Still no start. Is 6.6V low enough? I’m not sure how this works, though. I still get spark when I try to start the engine. Will it allow a few turns, then stop the ignition and/or fuel? I did buy a 100 OHM, .5-Watt resistor I will splice into that grey wire. When attempting to start, it will often “belch” burning fuel through the throttle body. If I take one plug out of a head, it will throw a flame through the open plug hole. I’m at a loss now and beginning to think my ECU has gone south. Any help is appreciated. __________________ 2004 Nomad 1500 2000 Excelsior-Henderson Super X Login or Register to Remove Ads
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04-24-2023, 04:17 PM	#2
Mechaniac Member Join Date: May 2022 Location: Magnolia, Texas Posts: 80	Test compression. If compression is good and you have spark disconnect the exhaust pipes or muffler if separatable and retry starting.
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