ECU not running pump on start

s300 and SManager software questions & answers
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mjalaly
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Joined: Tue Oct 28, 2014 1:34 pm

ECU not running pump on start

Post by mjalaly »

I'm trying to get my new engine started but what I'm finding is that I am getting fuel to the pump but no fuel out of the pump. It's a walbro running on hondata. It's wired up correctly because it will Prime with key on but if I try to start the engine I get nothing.

Not the pump since when I directly connect voltage to the pump it will build pressure.

Thoughts?
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Spunkster
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Location: Hondata

Re: ECU not running pump on start

Post by Spunkster »

You should test your ECU in a known working vehicle and see if it works with your ECU/s300.
mjalaly
Posts: 114
Joined: Tue Oct 28, 2014 1:34 pm

Re: ECU not running pump on start

Post by mjalaly »

i don't really have a way to do that. Everything worked before i rebuilt the harness and engine. Its trying to start. Datalog attached but not sure if it is telling me anything. For a short time it screen said 3 error codes but i could not find out what they were. not showing up.
start7.s3d
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Spunkster
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Location: Hondata

Re: ECU not running pump on start

Post by Spunkster »

It sounds like something is not wired correctly if it was working before you made changes to the wiring.
mjalaly
Posts: 114
Joined: Tue Oct 28, 2014 1:34 pm

Re: ECU not running pump on start

Post by mjalaly »

What inputs would tell the computer to not trigger the fuel pump? During data log the fuel sensor was activated.

Any ideas on what to check? It also has the distributor error.
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Spunkster
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Re: ECU not running pump on start

Post by Spunkster »

It's hard to say as you have altered the wiring in the vehicle and that is the first place you need to look.
mjalaly
Posts: 114
Joined: Tue Oct 28, 2014 1:34 pm

Re: ECU not running pump on start

Post by mjalaly »

I assume ECU pin A7 is a continuous ground from the ecu once the key is turned to ON. Correct? If so i can check this.
What inputs does the ECU need to trigger the pump after Key on? I assume all of the grounds powers (VBU s well), ICM and the dizzy inputs? Everything else could be off but still start?

can you help me understand from the data log if the ECU is sending signal to the pump? are there any tell signs?

thanks for your help too. Just trying to narrow down possibilities. I have checked all of the ECU connectors to their respective outputs any everything looks correct. Will do again though. The next thing would be to check for the right resistance, voltage output/input of each pin. I though I saw a list of each pin and it respective voltage etc but i cannot seem to find it again.
mjalaly
Posts: 114
Joined: Tue Oct 28, 2014 1:34 pm

Re: ECU not running pump on start

Post by mjalaly »

Ok to close. This was a polarity issue at the pump.
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