So I hotwired my fuel pump and then.......

[92EuroDiamante]

Ok, so as some of you read in my other thread, I was having some issues with a faulty fuel pressure sensor.
So while dealing with that I hotwired my fuel pump.
30amp relay, 8g wire. Wired off the stock relay thing (I know its not a relay, the unit that NAs have but the VR4s dont). Very confident I did everything right.
So I started the car dozens of times, everything was fine.
I drove the car a few miles and everything was fine.
Well today I decided to go for a longer ride. I took it on the highway and then slammed it. It got up to 4kish and all hell broke loose.
My relay thing (the little gold box) started going nuts, it was clicking like mad.
My RPMs were going crazy, My stock coolant temperature gauge started going up and down, the car was very unresponsive and felt like it was gonna die.

So I pulled off the highway and into a lot.
I let the car cool off, checked the engine bay for anything weird. Thinking it was the aftermarket hotwiring relay that was clicking, I removed that and wired the fuel wire to the stock relay. No improvement, I realized that wasnt the issue.

I started it back up and whenever I hit the brakes it really wants to die. I have to slam it into gear to get it to not die. I managed to get it the short distance home (it died a few times) with the relay box clicking like mad.

I know its not the fuel pump because the car idles fine, and when the relay box quits going nuts it will get up and go.

Any ideas? Did I miss something by hotwiring the stock relay, did I overstress it?
Luckily a guy has the stock unit locally for cheap but I really would like to know what is going on. Hoping I didnt damage anything. Doubtful as timing is still true and it never got past 4k.

[Steve '92ES]

Boy that kind of sounds like maybe your alternator died, what with the gauges going nuts and the relay clicking.
Do you have a voltage gauge, or a meter you can hook up, to see what the battery voltage is doing when things go wild?

[92EuroDiamante]

Yes I do have a voltage gauge. Voltage jumps around but that is because RPM is jumping around and the car is stalling.
Alternator is fine, its a freshly built H/O unit. Very thankful for it since I had to crank the car a crapload of times to get it going while the fuel pump relay was going nuts!

I know the problem is the fuel pump relay/ whatever it is called in this car. I just dont know what would cause it and if my hotwiring screwed it up. No sense replacing it if it will just blow next time I hit the gas hard.

[TUFFTR]

Its your battery that counts when cranking....not your alternator...just wanted to point that out.

[TUFFTR]

Check the ground from the new relay dude. Just double check all the wiring.

[92EuroDiamante]

I know that
but if I'm gonna be cranking away I want to make sure my battery is charged and that its getting the most charge possible in the 10 seconds before it stalls .
The stock alternators on the diamantes are not very good. What are the TRs equipped with from the factory?

[92EuroDiamante]

Check the ground from the new relay dude. Just double check all the wiring.

It still did it when I eliminated the new relay and just used the stock relay.

[Steve '92ES]

Voltage jumps around but that is because RPM is jumping around and the car is stalling.

Shouldn't jump that much. Even if the car stalls you should still have battery voltage. If it's dropping under 10v you've got a problem.
BTW, is this a turbo or NA? Also, I'm a little confused by this

Wired off the stock relay thing (I know its not a relay, the unit that NAs have but the VR4s dont)

Both have the MFI relay behind the passenger's side console. The turbo's also have another relay under the aircleaner that the NA's don't. Is that what you're talking about?

[Steve '92ES]

Oh wait. This is a Diamante?
I'm not sure I know what I'm talking about then...
Sorry...

[92EuroDiamante]

Shouldn't jump that much. Even if the car stalls you should still have battery voltage. If it's dropping under 10v you've got a problem.
BTW, is this a turbo or NA? Also, I'm a little confused by this.

Both have the MFI relay behind the passenger's side console. The turbo's also have another relay under the aircleaner that the NA's don't. Is that what you're talking about?

Didnt drop that much. I consider the change by a full number and the rate at which it was changing jumping around. sorry if I gave a wrong impression.

Yes I mean the MFI, forgot the term for it. Oh my bad, its been a while for me since I have worked on one.

as far as it being a Diamante, They are basically identical to 3/s other than body obviously. Other than some different suspension options and No 6 speed they were available in the same configurations. The one in question is N/A.