Help: KA-T fresh motor cant hold an idle, please help! (I checked all of the obvious) - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Tjk2world · 04-20-2017, 09:12 PM

Hello Zilvia,
Just got a KA and slapped it in my s13 after I blew my motor. So I get it all together and have a tuner come out to base map it (last motor was over bored) and we couldnt get it to idle so we could do some tuning. It would just pop alot and not even come close to idle.
I throw a new engine harness at it: same thing. So I figure the AEM V1 EMS is the problem and decide to go with a nismotronic setup. I get it all wired in and the same thing occurs. New plugs with a different heat range helped a little bit, it went from just popping to actually "idling" but pretty shitty at about 200rpm before it stalled out.
I noticed vaccum barely going down to -10psi and hitting the throttle would instally stall it so I pulled the intake manifold and replaced every single vaccum and pcv hose in the car, cleaned the Iacv, gave the FPR (stock) its own sepereate vaccum source (no longer tee'd off despite this working fine before, and cleaned the whole intake with carb cleaner this helped alot. My vaccum now goes all the way -20psi and when I turn the key it actually starts up like a real car, going right up to 1200rpm and not misfiring at all. When it starts to come down like a normal startup, it gets to about 1000rpm and starts seriously misfiring. Throttle sort of keeps it alive longer.

At this point I am lost. I replaced some rough looking wires on the distributor, put in a new distributor (old one started throwing CAS code), tried two sets of plug wires, tried unplugging each injector to see if it changes anything, checking grounds, adding grounds, tested tps (resistance was 1.7 at close and about 9.6 at open, decent results) Really cant figure this out!

Other relevant info:
No MAF
Aem 3.5 bar map sensor
Aem boost controller
Nismotronic with NEMU
KA-t
Nismo 740cc injectors
Chassis is 89 single cam auto chassis
Emissions deleted
Compression is 160-165 across the board

Timing is for sure correct! Chains and dizzy!

04-20-2017, 09:12 PM	#1
Tjk2world Join Date: Jun 2016 Location: Rhode Island Posts: 18 Trader Rating: (0) Feedback Score: 0 reviews	Help: KA-T fresh motor cant hold an idle, please help! (I checked all of the obvious) Hello Zilvia, Just got a KA and slapped it in my s13 after I blew my motor. So I get it all together and have a tuner come out to base map it (last motor was over bored) and we couldnt get it to idle so we could do some tuning. It would just pop alot and not even come close to idle. I throw a new engine harness at it: same thing. So I figure the AEM V1 EMS is the problem and decide to go with a nismotronic setup. I get it all wired in and the same thing occurs. New plugs with a different heat range helped a little bit, it went from just popping to actually "idling" but pretty shitty at about 200rpm before it stalled out. I noticed vaccum barely going down to -10psi and hitting the throttle would instally stall it so I pulled the intake manifold and replaced every single vaccum and pcv hose in the car, cleaned the Iacv, gave the FPR (stock) its own sepereate vaccum source (no longer tee'd off despite this working fine before, and cleaned the whole intake with carb cleaner this helped alot. My vaccum now goes all the way -20psi and when I turn the key it actually starts up like a real car, going right up to 1200rpm and not misfiring at all. When it starts to come down like a normal startup, it gets to about 1000rpm and starts seriously misfiring. Throttle sort of keeps it alive longer. At this point I am lost. I replaced some rough looking wires on the distributor, put in a new distributor (old one started throwing CAS code), tried two sets of plug wires, tried unplugging each injector to see if it changes anything, checking grounds, adding grounds, tested tps (resistance was 1.7 at close and about 9.6 at open, decent results) Really cant figure this out! Other relevant info: No MAF Aem 3.5 bar map sensor Aem boost controller Nismotronic with NEMU KA-t Nismo 740cc injectors Chassis is 89 single cam auto chassis Emissions deleted Compression is 160-165 across the board Timing is for sure correct! Chains and dizzy!