Alright I just did a s4na swap from my 88 rx7 to a s5 jspec t2 swap. I'm trying to pinpoint my issue and was hoping a few could chip in. i know its fuel related or tps. I'm actually still running the s5t2 tb and i wired the narrow-band tps (the one that sits in the front of the other) to work like it would in an s4 t2 car. I found on here that was possible, but now im getting different info. I'm also running s5t2 injected but its on a s4 harness. the harness didn't come with the resister pack wiring though so im not sure what year it could be. I know it was an s4. because i use the plugs off of the jspec s5 wiring and spliced them into this harness i bought from eBay. Just put a new walboro 255 in the car and the timing seems correct also. Still running the factory top mount with this and a 1gdsm bov in between the up pipe. Can anyone tell me where their vacuum line goes from the boost pressure sensor and their fuel pressure regulator? I just purchased an s4 t2 throttle body and should be in soon. I just don't wanna be spending money on the wrong thing. Sorry for jumping all over the place! Thanks

 

anyone?

 

Use the vacuum nipples on the front of the uim and/or the side for both, I just blocked off everything else (although I did block off all my emissions and my mechanical omp)

Block off anything that doesn't need vaccum by looping two nipples together with a hose by putting the vaccum hose from one nipple to the other, this is much better then putting a vacuum cap on.

Rotary > Pistons

 

The lack of paragraphs makes it really hard to read. I find it best to put each question on a separate line. Since one is asking for free help, it helps to make it as easy to help as possible.

Our swap was S5NA to S5 JDM Tii so I dont know anything about the S4 aspect. If you havent already I believe Landers has a writeup on Rotary Resurrection on the issues. Might be something you missed.

But since it is running I'd do the normal checks at the ECU of the TPS. If the TPS isnt set perfectly, it won't run right.

And then I'd pressurize the intake and look for vacuum leaks. These ECUs will tolerate absolutely no vacuum leaks.

 

what mode of ECU, engine harness, MAPS and AFM are you using? first, lets make sure you have a compatible combo.

any other relevant info will be a plus.

 

yea i was sorry for rambling. It was late and i had been up for hours with this thing. I will post the afm/boost sensor/ ecu models when i get home. I did a boost leak test and it built pressure just fine so its not that.

 

Measure the voltage at the Green/Yellow wire of your Boost Sensor and w/key to on it should read 2.2 to 2.5 volts. If it has 12 volts then you didn't account for the difference between the Emission Harness and the Front Harness especially if the Front Harness is from the S4 and the Emission Harness is from the S5.

 

Ok well the mass air is a 318 the ecu is a 332. and there are no numbers on the boost pressure sensor. I purchased that from a member on here that said it was a s4 t2 pressure sensor. All of the harnesses are from an s4. it plugged right into the s4 ecu. I will check the volts though. Im thinking its my injectors or tps. im running s5 injectors spliced into the s4 harness with no type of fuel injector resistor. I had no plugs on the harness that i could see for it

 

You can take an ohm test of the injectors to prove if they are the older low ohm variety which required the resistor box. Actually, an S4 Tll Emission Harness is not compatible w/the S4 NA Front Harness as some changes would need to be made.

The Brown/Red output wire of an S4 Boost Sensor would be the wire to be measured.

 

I will try the ohm test. im pretty sure they are s5t2s i got all the paperwork from the engine set. and the plugs wouldn't fit the s5 harness. I had to extend some wires as well. Its a full s4 na harness with no emissions.

 

ok tps is dialed in correct. I think i found my issue lol. i went to test the volts in the green/yellow wire and it showed no volts at all. can you tell me all of the colored wires that hook up to the boost pressure sensor to make sure i dont have it hooked up to the wrong plug? also if its correct what would cause it to have no volts in the harness? is there a plug around the ecu that i may have missed?

 

To clarify things you have an S5 engine but are using S4 engine sensors? Correct? S4 Boost Sensor requires 4 wires, S5 3 wires.

 

s5 turbo engine. but im using all s4 stuff atm besides the manifolds/injectors/tb. My wiring is a 4 wire

 

There is some under the dash stuff by the ecu that looks kinda mangled. The previous owner yanked out the ac and all of the engine bay stuff because he was going to put a 1uz in it and i just happened to save it. I did see some kind of pressure sensor around the passenger kick panel that had wiring going to it. I just dont get how it will start up and let me rev it and then just die if i take my foot off the throttle. It has a brand new Walboro 255 as well.

 

The 4 wires at the sensor are as follows. First off there is no G/Y wire at this sensor (found on S5's). B/W wire has 12 volts w/key to on. Br/White has 5 volts w/key to on. Blue/White wire is the output wire which should have 2.3 to 2.7 volts w/key to on. Final wire is the ground wire.

The ATP sensor is the pressure sensor by the kick panel.

 

Ok well when i checked it early. one had about 12 volts and one was close to 5 volts. but i dont think the other 2 registered anything. In your opinion. what could let it start up and let you rev it while its fighting to shut down?

 

Vacuum leak.

 

i did a boost leak test and i didn't hear much. just sounded like you could hear some air going through the turbo or top mount intercooler. I will try it again tomorrow. thanks

 

ok just tried the boost leak test again and you can hear the air somewhere around the turbo or intercooler. is that normal? im about to try the soapy water trick. stay tuned