Fuel Pump Wont Stop!

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frankp2112
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Fuel Pump Wont Stop!

Post by frankp2112 »

Hi,
Just had my unit fixed as the Q3 transistior was faulty and would not earth the fuel pump..

Now it runs the fuel pump constantly.

When i disconnet the Ms and turn on the ignition the fuel pump does not run.
When I earth the fuel pump lead to the MS the pump runs.

Any ideas what could be going wrong?

Thanks

Frank
Matt Cramer
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Re: Fuel Pump Wont Stop!

Post by Matt Cramer »

Does the fuel pump LED stay stuck on when you test the MS on the Stim?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

My pump stays on, on the stim. What can it be?
Currently running MS1 V 3
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

Nobody have an answer?... Or a link I didn't find?
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
DaveEFI
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Re: Fuel Pump Wont Stop!

Post by DaveEFI »

Does the pump run with the processor card unplugged?
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Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

Haven't tried removing the processor again since I actually got the fuel pump light to light up. Now I just need it to stop when it doesn't see rpm.
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

Pulled out the processor and the fuel pump light comes on when powered up on the stim.
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
DaveEFI
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Re: Fuel Pump Wont Stop!

Post by DaveEFI »

You still have a fault on the pump driver circuit.
Rover SD1 3.5 EFI
MS2 V3
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Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

Well it looks like I'm going to have to change the resistors and diodes then. Already changed Q2 and Q19.
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
DaveEFI
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Re: Fuel Pump Wont Stop!

Post by DaveEFI »

If the zener is short circuit, the relay will be made all the time there is power. Very unlikely a resistor is faulty unless obviously burnt. Are you certain there are no solder bridges at the transistors?
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MS2 V3
EDIS
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Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

DaveEFI wrote:If the zener is short circuit, the relay will be made all the time there is power. Very unlikely a resistor is faulty unless obviously burnt. Are you certain there are no solder bridges at the transistors?
I first replaced Q2 and that fixed the issue of it not turning on. I replaced Q19 with the hopes that would stop it from continually running with no rpm signal. Checked the transistors with a magnifying glass and it doesn't look like I have a solder bridge, I could be wrong. Bought this ECU used from someone else so I have know idea what the previous person did and what they burned up.

Good news is when I plug it in to my startup stand with a motor on it, it runs. :yeah!: So it's just this little deal of the pump not shutting of with a lack of rpm signal. Thanks for the help this far.
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

I purchased all the pieces for the circuit. So if the zener is bad, I can change it.
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
DaveEFI
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Re: Fuel Pump Wont Stop!

Post by DaveEFI »

Corysvdub wrote:I purchased all the pieces for the circuit. So if the zener is bad, I can change it.
I'd guess you could check if it is short circuit in situ. Also double check it is installed the correct way round.
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Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

Ok, well changed everything in the circuit and got the fuel pump light to go out on the stim when it doesn't sense a rpm. Should work when I plug it in to a relay box right? Negative! Fuel pump stays on! Plugged in another ECU (ms2) into said relay box and it functions like it should. So what do I do now?....
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
Matt Cramer
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Re: Fuel Pump Wont Stop!

Post by Matt Cramer »

If you retest the board on the Stim, does it still operate correctly there, or does has the light become stuck on?

If it's the former, you may have a relay that generates an odd amount of flyback and is damaging the transistor. Running a 24 volt zener diode from pin 28 to pin 30, banded end to pin 30, could help with that.

If the board checks out correctly on the Stim, see if you get the fuel pump to turn on if you put the board on the car, but with the processor removed.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

I retested on the stim and the light goes out like it should.
Matt Cramer wrote:If you retest the board on the Stim, does it still operate correctly there, or does has the light become stuck on?

If it's the former, you may have a relay that generates an odd amount of flyback and is damaging the transistor. Running a 24 volt zener diode from pin 28 to pin 30, banded end to pin 30, could help with that.

If the board checks out correctly on the Stim, see if you get the fuel pump to turn on if you put the board on the car, but with the processor removed.
I put it back on the stim after trying it on my startup stand and the light goes out like it should after a few seconds.

Hooked up my ms2 to the same relay box and it functions like it should so that kind of eliminates the relay board being faulty right?....

Would like to get this figured out, I was super excited when it worked on the stim and thought I was finally done figuring this thing out. Then really bummed when it didn't work on the stand :cry:
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

I will try the removing of the processor later this evening
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

Pulled the processor and tried the ECU on the stim, no fuel pump light. Plugged it into the startup stand and no fuel pump.
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
Matt Cramer
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Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: Fuel Pump Wont Stop!

Post by Matt Cramer »

It sounds like you're getting some sort of false RPM signal triggering the pump.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Corysvdub
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Re: Fuel Pump Wont Stop!

Post by Corysvdub »

Matt Cramer wrote:It sounds like you're getting some sort of false RPM signal triggering the pump.


How though? Pump light goes out on stim and other ECU runs fine on the same relay box.
MS1 V. 3.0 Not assigned to a motor
MS2 V. 3.57 Subaru Powered Squareback
Microsquirt Startup Stand W/ turbo EJ25
MS3X Subaru EZ30D Finished!
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