okay I recently rebuilt my motor and dropped it in the car and I got it running but I'm having some issues, but this is my general setup:

S4 car w/ s4 electronics
S5 irons large streetport
S4 rotor housings, pineapple streetport
megasquirt 2vb3 to come after its broken in and whenever its assembled.

I keep trying to set the timing but its like its off a tooth, I can get it to run and the lowest idle I can get out of it is around 1500.

the car has s5 manifolds on it and etc but I'm also using an S5 throttle body and TPS, so I just been using the narrowband signal but the car runs when I have the TPS unplugged, TPS is within spec, did the whole light tester and everything.

BAC is installed and functional

when it runs you can hear it missfire.

when messing with the timing Its like there isn't enough retard to make it run smoother, if I could retard the timing more it would work.

I keep re stabbing the CAS and checking timing and it seems dead on.

fuel system is not a problem, everything is working out fine.

tested cooling system and comp and they came out great.

so do I just borrow an S4 TB with TPS until I break it in and use the s5 one when the squirt is installed

I need some help, I just want it to idle and not missfire. it feels like a mixture problem. Could my port job affect this?

 

If you had mad overlap your car would want to idle pretty high I think.

Are you sure you don't have any vacuum leaks?

Stuck or too tight throttle cable?

Idle adjust screw too far in?

 

I dont mind if it wants to idle at 1500rpm, I can kinda get it lower but you it just misses and wants to die.

I don't hear any vacuum leaks and I haven't found any...
(although it seems like the likely culprit)

been messing with the idle adjustment screw and it doesnt do **** really....

I dont see how I could have given it too much overlap with a streetport, maybe I went too far with the port opening timing...

throttle cable is fine



I gotta try an S4 TB with TPS because right now it runs without the TPS plugged in but it wont idle.

should I try adjusting the variable resistor?

it misfires across all rpm not just idle-ish speeds.


but it does sound good, I'll get a video of it soon.

 

tps?

 

throttle position sensor

 

The TPS is more of a indication to the ECU about a sudden pedal change rather then an extremely important sensor. It helps the ECU have a smoother transition into full throttle. The fact that it idles with it unplugged is irrelevant.

If its missing all the time you might have another problem.

 

Unless you can get your idle speed down below 1500 then any timing reading you take will be WAAAAY off as well as the idle mix screw will not work either. And dont let anyone tell you the ISC is locking the timing because it ISNT. Its just disabling the BAC.

 

I can get it around 1000-1200 but its tricky.

and ISC?

 

you have s4 electronics? but a s5 tps? do you have a s5 ecu?

 

I have s4 electronics, including ECU but the only TB I had laying around was an S5 NA TB with TPS, I sold my old S4 TBs with TPS's over the last few months because I would modify and P&P them

so I checked the schematics and tried wiring just the narrow band TPS by looking up the pin connectors but no luck. the S5 narrowband signal may be different than the S4 narrow band signal.

I have a franken wankel.

 

You will probably have to rewire the S5 narrow band, but the signal itself is, as far as I know, the same.

 

I tried that, doesnt work. ^