PLEASE HELP ANYONE, PLEASE,

[apexnfever]

I own an apex mtn, really weird, running great no turbo, still stock, had the sled sent in to be re-clutched as it was hitting the rev limiter, once the dealer took it out for a test run it shut down,will turn over, but no fuel is being pumped to the motor, I had a diffrent fuel pump hooked up, and still same problem, when you hook up the plug to the fuel pump, at the fuel pump, and stick volt meter on the two lines one red one black, the power is shut down, unplug the the wires from the fuel pump, and the volt meter reads 12 volts, plug it back in, and the volt meter reads no volts, so once it is pluged in no volts, I took a 12 volt battery hooked it up directly to the fuel pump, and the sled will start the fuel pump does run continously, but still it shows that the pump is ok.

So somthing electrical is shutting down the power going to the fuel pump when it is pluged in, but when its unplugged it has power all the way to the plug that plugs into the pump at the pump.

Confuessed someong help please.

No codes at all come accross.

 

[Tork]

Sounds like the fuel pump relay, acouple of others have had this problem.

 

[apexnfever]

where is the fuel pump relay, is it the one that is above the left foot behind the cover.

If so we swaped it with the one right next to it had the fuel pump unplugged, and still same problem, and you can hear the relay click on when the key is first turned on, and click off 2 seconds later like it does when the sled operates normally, it cycles the pump to build up the pressure to 36 lbs and after the motor starts the fuel pumps truns back on.

Now when I plug the fuel pump in, and turn on the key it trips the relay right away, instead of two second delay.

So the relay clicks and does what it supposed to do, but no pump at all.

 

[Mighty]

Sounds like the dealers problem to me...............

 

[Tork]

you have 12v until you add a load (fuel pump)

A relay can click and still have a bad connection between the contact points. Dont know where the relay is. The system is likely to have a pressure switch unless that is built into the pump.

It sounds like a weak connection in one of the components, or wiring.

When you add the fuel pump, volts drops right? Do you still have volts on the input side of the relay?

 

[apexnfever]

Sounds like the dealers problem to me...............

yea but I have a big ride for this weekend planned.

I feel it may be a shaffed wire grounding out, or ECU, ecu because it controls all the wireing, shaffed wire being grounded because I am not getting any codes.

 

[Mighty]

I gottcha.

 

[apexnfever]

you have 12v until you add a load (fuel pump)

A relay can click and still have a bad connection between the contact points. Dont know where the relay is. The system is likely to have a pressure switch unless that is built into the pump.

It sounds like a weak connection in one of the components, or wiring.

When you add the fuel pump, volts drops right? Do you still have volts on the input side of the relay?

Great points, when we plug in the fuel pump at the pump, (connector right on the top of fuel pump) no volts at all, goes to zero.

when I unplugg at the fuel pump full 12 volts are supplied right to the plug at the fuel pump.

We unplugged all plugs and cleaned them, and plugged them back in.

moved all wires to test for shaffing, only 1900 miles are on this sled and no major accidents.

By passed tors as well, tested the relays with volt meter, and all ok.

 

[apexnfever]

I gottcha.

I own an auto body shop, and deal with things like this, and I feel that if I am there helping, they put more effort into solving the problem, they all are a great group of people, and I just want to solve the problem.

Relays, wiring, sensors, we deal with it all the time at my shop, so testing and checking volts is something I do know about a little.

they are helping in every way to fix it, I just want to be involved to help it get fixed.

 

[guardrail]

Try checking to see if the 12v from the computer is at the relay(thinner wire) when cranking. I'm not sure sure if the computer has relay, but if your losing the 12v while cranking its got to be in the starting circuit. If you have the 12v while cranking, then it sounds to me like its the wiring on the fuel pump side of the relay. The 12v coming from the computer to the relay is isolated from the fuel pump. The relay is there to handle the higher current draw from the pump. The computer can't handle any significant current. I would disconnect the plug from the fuel pump. Get a jumper wire and ground the pump. Then run a jumper wire from the fuel pump side of the relay(heavy wire) directly to the to the positive side of the pump. Try to start it. If that doesn't work remove the jumpers and reconnect the plug on the pump. Next, run a jumper from the battery to the battery side of the relay. All the relay does is complete the circuit between the battery and the fuel pump. If this works the wiring from the battery to the relay is bad. This should eliminate any problems on the that side of the circuit.
I would have given wire colors but I'm out of town right now. I don't carry my manuals with me,
Hope this helps