Do all F.A.S.T. ECUs have fuel pump trigger?

[fast4d]

I just installed a FAST system in my '89 mustang. I'm not getting a ground from the "fuel pump" wire when the ignition is on. I had to ground my pump relay manually to get it going. I got my engine started for the first time today. The fuel pump field in the dash shows a "0" which means "off" I suspect.

Any ideas?

 

[bobc455]

When you say that you are not getting a ground, does that mean that you are not getting continuity to ground from that pin? If that's how you are testing, then I don't think you will see continuity because instead of actually grounding it, it drops it to 0 volts or something like that. Maybe some EE can explain it more or correct me.

Anyhow, the fuel pump should be activated when you first turn the key forward (as determined by the fuel pump priming timer), and then again once it sees RPM from your motor (either your distributor or cam sensor or however you feed the ignition signal to the ECU on a Mustang). If the ECU doesn't see any RPM, it won't turn on the fuel pump (unless you just turned the key forward).

-Bob Cunningham
bobc@gnttype.org

 

[fast4d]

The pump prime time is set to 25 sec right now.

I used a test light to test (1 end to 12v the other to pump wire from ECU).

I'm going to try a volt meter next.

 

[bobc455]

I don't think a test light will work.

You should just be able to watch the dashboard and see if it changes from 0 to 1, that will tell you if the ECU is trying to run the pump.

-Bob Cunningham
bobc@gnttype.org

 

[Craig Smith]

What is the part number of the ECU?

 

[fast4d]

Originally posted by Craig Smith
What is the part number of the ECU?

fuel pump field in the main dash shows "0" when engine is running.

part number is: 30-114010

firmware: B2BLT1-R

 

[Craig Smith]

I don't remember if the fan and fuel pump flags in the dashboard work with the version of firmware you have, but there's no reason that the pump shouldn't turn on. Did it ever work? Do you have it set up so that the fuel pump output from the ECU grounds a relay to activate it? It should just work!

 

[fast4d]

I bought the system used. The previous owner probably didn't use the FP output from the ECU since it was a 100% track car. I'll ask when I get a hold of him.

I did hook it up to a neg trigger on the relay. To be sure I had the relay correct I grounded that pole on the relay and pump came on.

Is there a test I can perform to be sure the ECU is not damaged?

Thank you for your help.

 

[Craig Smith]

Do you know if the fan or the nitrous outputs work? They are all driven internally by the same part. If there is damage it is likely that these outputs would also be affected.

You should be able to use a test light to verify these outputs. They should provide a ground signal to activate the test light. Since you already know the pump output isn't functioning, I would try the fan output for the test. Also check to see if the "fan" flag in the dashboard corresponds with the output you see on the test light.

Let me know what you find.

 

[fast4d]

I'll try testing the fan output asap. Thank you.


What'll it cost to repair the ECU if it's indeed the problem? You can email me if necessary, Craig.

 

[fast4d]

fan output is grounded ALL the time

I just tested the fan output from the ECU. I hooked up the test light with the ECU OFF and got a ground.

I started the engine COLD test light stayed on. The "turn on temp" is at 180 F. On the dash fan field shows "0" until turn on point is reach. Light stayed on the entire time.

What do you think?

 

[Craig Smith]

I'm kinda starting to think that I can smell the burnt chip in your ECU from here. If the fan, fuel pump, or nitrous output lines touch +12V or get hooked directly to an accessory instead of a relay, it tends to let the smoke out of a chip in the ECU. It just doesn't work without that smoke in there.

Check your email...

 

[whiteturbolx]

Craig,

I sold Alan that speedpro unit from my own personal car. It was a unit I bought from Jim Summers at ASSC in late 99 before I was a dealer for your stuff while I was at Texas Jam. Murillo set that thing up to use the fan and fp outputs at one time, although I did end up wiring the Weldon pump up to a switch panel so we could run the pump with the motor off if we wanted. We're positive that they did work at one time, although it had sat in a box for the last year. Never did use the nitrous output. One interesting thing about that unit was that the water temp and air temp was reversed on that harness. Almost caused me to "let the smoke out of" a brand new $20k turbo motor. hahaha

Shane Hill

 

[whiteturbolx]

Oh......and the flags for fuel pump and fan operation were shown in the dashboard with that firmware. I've got another car sitting here with the same unit, bought at the same time, that I verified that on.

Shane

 

[Craig Smith]

Shane,

thanks for the input. Given that you had it working, and that you
HAVEN'T mentioned miswiring it at one time, I would have to presume that the necessary smoke is still where it needs to be in the ECU. However, it looks like we've covered everything we can here on this board and still no luck. I spoke with Alan and he is going to send me the unit for inspection - that way we'll know for sure. He's verified that all of his wiring is correct by grounding the negative terminal on the relay and activating the pump, so we'll just hafta figure it out one thing at a time.

thanks again!

 

[fast4d]

Thank you Craig

I just want to thank Craig for the fast turnaround. He got my ECU repaired and out the door in 2 days.

I tested the fuel pump circuit yesterday and it works fine now. Now I can continue to tune this thing.