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So much for having a running car. I was planning to take the car in to get the exhaust connected as it is running with an open header but she is being tempremental. Originally I thought is was the battery (I still think it is one factor) since at start up it reads 14.4V but the minute I crank the motor it is between 12.0-12.4V so it won't start. The battery has been on the charger for the last few days, hopefully it can recover from its long period of just sitting. BTW, it is a good battery, Optima red top.<p>Next problem, I am running a FC3S fuel pump, very loud and noticeable. Problem is that I don't hear it. Since it is ran off the battery to bypass the skinny factory wires, once the key is put in and turned to the "ON" position it starts to run. Not hearing this anymore. I have checked the fuse and it appears fine. I will check the switch to see if that has gone out on me. Next thing would be the pump, might have to put the old one back in.<p>Ecu is only pulling a code 41 which is of no importance as I am running the Pro lx ecu, not the mx-3 ecu. Not sure what else I should look for. Tomorrow I will start trouble shooting and see if I can find the problem. Any ideas from you guys?

yeah, aeromotive 1000hp fuel pump and a standalone <p>all joking aside. did you use a relay to power up the pump? if not its probably the switch. they dont take much before they go. just jump it for now and see if it fires up.<p>as for the battery going down to 12 volts when cranking, thats completely normal. starters draw alot..id have to test this to get an actual number but that sounds correct. when we test batteries at work anything under 9.6 volts while doing the load test fails. that gives u an idea of what they can drop to. although if you have a bad ground or a faulty starter it can have that effect also. and this would only happen while cranking so battery voltages would remain correct. let me know how things go

Should have said that the battery drops voltage after cranking failed, not during. After trying to crank it once, the battery has discharged enough power to only register 12V or so.

sounds like its beat. throw another one in there to see if it eliminates the problem.

before you do that maybe try boosting your car with another and see if it starts with the extra juice

when we did my swap a couple tries at cranking and the battery would be dead...
check the relay and/or switch. my pump didnt wanna act right until i put it in test engine mode... but i'm sure thats done from the B6T swap u did...

Well it isn't the battery.<p>Here is the strange thing: I did have the car running since putting in the new radiator and it ran fine. On Monday I started the car up, it ran for about 10 minutes then slowly died. After this, nothing would get the car running. Using the voltmeter, I traced the power supply to the fuel pump. When I installed the FC fuel pump, I rewired the entire system directly off the battery using a 30amp relay to overcome the tiny wires that Mazda uses. This setup worked fine when I originally rebuilt the motor and up until Monday. I discovered that the wire that I was using as a 12V switched no longer was "switched" for some reason. The wire that I am refering to is the black/red wired on the fuel pump harness under the rear seat. Doing some testing and jumping of wires I found that the very small white/red wire was a 12V switched wire. I swapped the wires, reconnected the black/red to its original destination and everything fired up fine. I still have to check my wiring schematics to determine what wires were designed to do what.<p>Strange....

if the problem persists just run your own switch and relay, it would probably be alot better for the pump and ecu anyways.