Error 43 no start

[Sugarkryptonite]

The ground you probe at the starter relay comes from the key switch. It provides a ground signal to the starter solenoid to control power to the starter. That same wire from the key is spliced and that ground signal is also sent to the ECU so that the ECU detects the start attempt. Clean the connector behind the key switch (even if it doesn't look corroded it can form a white oxide layer that won't conduct). Did you check the harness rub points (especially the one under the steering post)?

Okay thanks. I checked quickly but it's hard to see back there. Better to take the whole airbox and steering shaft out?

 

[74Nitro]

Hook everything up. Then jump the red/green and red/blue at the fuel injection relay. This will power both the pump and injectors. I would use a fuse in the jumper wire to be on the safe side.
This should help narrow down where the problem lies.

 

[Sugarkryptonite]

To inspect the wiring harness under the steering column, air box needs to be removed, correct? How the hell do you gain access to the bolts that hold the runners to the intake manifold? Seems like to take one thing apart you need to take apart 3 other things first. Crazy.

I have done current carrying capacity tests on all wires that go to the fuel pump relay, and they all check out. ECU seems to not be sending ground signal to turn pump on. Error 43 and then 12 was also showing. Is there anything the ECU checks for/needs to see before turning the pump on?

ECU has all its grounds and powers and they are intact.

 

[grizztracks]

Have you swapped the fuel relay with one of the others yet? The fan, load and fuel relays are all interchangeable. The fan and load relay are not needed to start the engine, just the fuel relay is needed.

 

[Sugarkryptonite]

Have you swapped the fuel relay with one of the others yet? The fan, load and fuel relays are all interchangeable. The fan and load relay are not needed to start the engine, just the fuel relay is needed.

Yes long time ago. No change. Also changed my starter relay to a new one. No change.

Definition of code 43 is "Power supply to the fuel injectors and fuel pump is not normal"

But where is the ECU checking that power supply exactly? The only power I see at the fuel injectors and pump is once the relay is connected, and that wire splits to the pump and injectors and also goes to the ECU.

How can it know the power is not good if the relay isn't closed?

Highlighted in yellow

 

[cannondale27]

Does it crank and run with key engaged to start position?

 

[Sugarkryptonite]

Does it crank and run with key engaged to start position?

Not sure what you mean. The machine doesn't run at all but yes it will crank as long as you want it to.

 

[Sugarkryptonite]

I went through all the wiring today. Checked all the common spots, even opened up the harness at those spots. Turned out to be a waste of time. This machine is a major pain in the #*$&@ to work on. Every single thing I touch is hard to get to or needs 3 other things removed first.

Anyway, I am convinced that I have fried a transistor in the ECU that controls grounding the fuel pump relay...I must have done it by accident when the fuel pump wouldn't run the first time. Not sure what I did. I will have to run it with full time key on power for now until I manage to get another ECU to test.

 

[Sugarkryptonite]

Well I’m at a loss.

Set to DC volts. Key on. One lead on the positive coil side from the fuse starter relay at the fuel pump relay, and other lead on the ground coil side from the ECU at the fuel pump relay. Gives 12V!!!

Set meter to continuity/resistance. One lead on the ground coil side of the relay from the ECU, second lead on negative battery removal or other ground. Open circuit!! How is that possible.

Can measure +12v on the multimeter but seemingly no connection to ground???

 

[smokingcrater]

Well I’m at a loss.

Set to DC volts. Key on. One lead on the positive coil side from the fuse starter relay at the fuel pump relay, and other lead on the ground coil side from the ECU at the fuel pump relay. Gives 12V!!!

Set meter to continuity/resistance. One lead on the ground coil side of the relay from the ECU, second lead on negative battery removal or other ground. Open circuit!! How is that possible.

Can measure +12v on the multimeter but seemingly no connection to ground???

Going to ask the obvious, when you were testing resistance did you first touch the meter leads together to make sure it zero's out? (aka bad meter?)

 

[74Nitro]

If you go through self diagnostics what voltage reading do you get?

 

[YukonMP]

Going to ask the obvious, when you were testing resistance did you first touch the meter leads together to make sure it zero's out? (aka bad meter?)

I do, and my meter has a dial to that I can zero the reading.

I still have the original box for the meter and receipt is in the lid ... 34.95 in 1984. How is that for a pointless comment in your thread.

Good luck with your issues, I've been following and you have a stinker.

 

[Sugarkryptonite]

Going to ask the obvious, when you were testing resistance did you first touch the meter leads together to make sure it zero's out? (aka bad meter?)

Yup

If you go through self diagnostics what voltage reading do you get?

It shows 0.0 for fuel system voltage. I still can’t figure out where it reads the voltage from.

 

[74Nitro]

I've had this happen twice on Nytro's and both times it was the female pin connector inside the plug that plugs into the starter relay. It just wasn't crimping the male pin anymore. You're sure that it's all good in there?
Where are you located.

 

[Sugarkryptonite]

I've had this happen twice on Nytro's and both times it was the female pin connector inside the plug that plugs into the starter relay. It just wasn't crimping the male pin anymore. You're sure that it's all good in there?
Where are you located.

I'll double check that tomorrow, thanks. I checked the other end of the wires that leave there and go to the ECU and they all seem to be fine, though. I'm in Montreal