1985 LTD problem

[glock20sam]

I have an 85 LTD that will start when I press the starter button, but then dies as soon as I release the button. Anyone have any ideas?

I have replaced the fuel pump, all of the fuses, injectors, and the computer.

Thanks.

[Rambozo]

Sounds like an open ballast resistor.

[Rednaxs60]

No ballast resistor on the '85 Limited Edition. Are there any error codes generated by the ECU? Do you have the three manuals; OEM service manual, Electrical Troubleshooting Manual, and the most important - the Supplement. Don't leave home without these.

The starter button only turns over the engine, has nothing to do with the operation of the engine. The ECU controls whether the engine continues to operate or not, this is why I ask about ECU error codes.

The start up sequence should be:

Key to the ON position, fuel pump should operate for 3-4 seconds to prime the fuel system (you should be able to hear this)
The dash goes through a start up sequence, after which the only dash indicator lights that should be illuminated are the gear selector, and the oil lamp.
No error codes, the "FUEL SYSTEM" light would be on if there were, push the start button and the engine should start.

The FUEL SYSTEM light is Honda's check CFI system components, one or more of the CFI components are not sending a signal to the ECU. The ECU does not monitor the fuel supply system.

If you think the fuel supply system is not operating correctly, you need to check for fuel system pressure. Static with key ON engine not started, should be approximately 36 PSI, dynamic with engine started 28 to 32 PSI. There is a fuel pump flow requirement as well.

The other FUEL indicator lamp is a low fuel level indicator.

Check the 30 amp CFI system fuse that is connected to the "B" terminal of the starter solenoid. This is the white wire. Maybe a hairline crack in the dog bone fuse.

The crank sensor, Ns, has to be good. If not the engine would not start. The TPS can be out of calibration, but would not stop engine operation.

The other sensors are robust and don't fail too often.

Take the plugs out and check for spark.

From your description, about all that I can offer at this time.

Good luck.

[glock20sam]

Thanks for all of the information.

I have all three of the manuals and have been immersed in everything they have to offer in print. The schematics have been a great resource.

I will try and do some more troubleshooting with the info you have shared.

This is a beautiful machine and I would love to solve this problem before the next riding season. It doesn't deserve to just sitting in my garage.

Thanks for all you have offered!