Lets suppose there was some idiot, just some guy, joe shmoe who happened to have a roller that used to be a stock S4 TII. And let's say for the sake of argument this guy put a stock S5 NA motor in it. Do you suppose this fellow, might have problems with the stock S4 TII fuel pump and the S5 NA fuel lines, etc? Y'know, just a theoretical question...

 

the pump would be too powerful and overwhelm the fuel requirements for the N/A engine.
Solution: put an N/A pump in it.

 

I'll try swapping to NA pump, thanks for confirming my suspicions.

I figured as much. When I put a new starter in, suddenly it turned over great, but acted like it was being flooded. I realized that by lowering the resistance on the system at starting, current was increased through the whole system, including the fuel pump, thereby increasing power, because P = IV. So the TII fuel pump is probably finally getting the power for which it was rated, and I guess providing too much fuel?

 

You may want to look into bypassing the fuel pump resistor also..down the line.
they seem to play games with the voltage to the pump.
You can find that info easily when you search.

 

Welp, got a new fuel pump...and... still no good

I have new spark plugs, new starter, new battery....

and yet won't start, but it did a week ago back when it had old stuff... wtf. It acts like it's flooded, I usually have to spray starter fluid in the air intake and jump it to give it enough power to crank the starter fast enough.... and then the plume of white smoke (like it's flooded). And it runs great once it's going.

 

another couple of observations here.
the S5 Engine has an Electric OMP so either you need a S4 front cover and mechanical OMP or premix the gas.
Also,the 5/6th ports are electrical on the s5 so you need to address that.
But basically turning the S5 engine into an S4 will help to achieve this swap.

If the s5 injectors were wired in then the Harness would need to be compatable..
that means that IF the injectors on the old setup ran with the harness that had a Resistor pack (for LO impedance injectors) then it would need to be bypassed.


You got your work ahead of you.

 

This is common with the na ser 4=5 check your injectors for leaking or stuck open ;Have them serviced and will proberly fix your problem

 

That was taken care of during the rebuild. It has a block plate and bypass chip in the ecu. Gas is premix.

I figured the guys who rebuilt would know if that was addressed, but I guess it's my problem now, so I'll have to double check it all.

Again the guys who rebuilt it should have dealt with the issue, but I have no idea if they did it right or not.

indeed, it would seem that I do. wondering why I paid so much now if I have to go over all the work again

I'll do that. When the engine was rebuilt I believe the original rail was used, and IIRC those components had 150K miles on them, so who knows. I'll check.