3400 problem

[Tylerlp]

So I DID search this and I couldn't really find anything about this but I just swapped to a 3400 from a 4 cylinder and I'm wanting to work out this one odd problem. I am using a 95 v6 wiring harness and what I'm running into is that when I push the throttle all the way to the floor the engine will cutout and of I hold it there it will die. so what could be causing this problem?

[berettaboi]

if it is not a ECM issue, (which one are you using?), and not a sensor issue, if you have spare coils and maybe an ICM (the coils mount on) that's an easy thing to try.

could also be a weak fuel pump... quite a few possibilities.

[spacecadetz26]

what fuel injectors are you using?

[Tylerlp]

Im using a 94 z computer and the 3400 injectors. The car accelerates and drives fine. It only cuts out at full throttle

[DTMAce]

Wait.

A 94 computer for a 95 harness? Can you do that? I know they are supposed to be similar, but I think the 95 has a different wireup for parts of the harness, but not sure what parts. But I'm sure to be pointed out wrong, and if so, cool.

3400 injectors require more fuel pressure though than the 3100 injectors, so not sure how well that will work. Does it cut out like someone turned off a switch, or does it fade and stumble out?

If it just shuts off completely like a switch, then it sounds electrical, or as if something is protecting itself, like the 3100 does when it hits an RPM limiter.... Or an issue with the computer and the ignition, good lord, could be a number of things.

If its stumbling and like gasping when it cuts out, then its simply not getting enough fuel under WOT conditions, which means you may need to upgrade the fuel pump, or at least change the fuel pressure regulator to attempt to compensate, providing the pump is working well enough. Or go back to the 3100 injectors.

[Tylerlp]

It turns off like a switch got turned off...and that computer works fine with the harness as far as I can tell. I don't think that's what's causing this though

[3X00-Modified]

Is it in park or neutral? If so there is a 4k rev limiter...

The 3400 injectors if they are pre 2000 versions which I'm assuming they are they do not need higher fuel pressure they are 43.5psi just like the 3100 ones. The should be short fat injectors with a red ring. Anything that is a thin pencil like injector that you had to splice wires onto the injector harness to work will require 55psi since they are all 2000+ styles.

As Ace said it could be a number of things going on especially since you are mixed and matched here with parts and don't have any scans or logs to verify whats going on.

[spacecadetz26]

whats your fuel pressure? try taking the vacuum line off the fuel regulator and checking it also.

check your spark when your wot

start with the basics, fuel, spark, air, compression with any driveability issue. then trace the cause to what issue your having.

[Tylerlp]

It does it while I'm driving down the road! It sucks lol

[3X00-Modified]

What is the RPM when it does it? And how do you have the trans hooked up to this wiring harness? gear selector wise and speedo and such... since the 94 ECU isn't meant for a 3t40 I'm wondering if it does think your not in D and it's hitting some sort of limiter.

[Tylerlp]

The 94 z26 had the 4t60e...

[DTMAce]

Yeah, even that threw me off a bit. 94's didn't have 3t40s. And he is using the computer out of a Z, not his base one which probably was a 3t40, now that I think about it. Forgot the auto based 4 cylinders had different autos. lol

[spacecadetz26]

What trans did u use?

[3X00-Modified]

Last I heard you had a 3t40 in there or you blew one up at least and was switching to a 5-speed...

You never stated you have a 4t60e now. or do you?

WTF is your setup?

I corrected my earlier statement I meant to say the 94 ISN'T meant for a 3t40 trans.

[Tylerlp]

Haha I'm sorry guys...I just recently put a 4t60e in. I couldn't get ahold of a getrag