Help: KA-T fresh motor cant hold an idle, please help! (I checked all of the obvious)

[Tjk2world]

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!

[hanzbrady]

What's your ignition timing look like while cranking/idling?

[tuzzio]

How is your throttle cable set? and the screw on the TB

[Tjk2world]

What's your ignition timing look like while cranking/idling?

I assume that i would check this in my tuning program? My bew laptop is in the mail, but when it gets here what doni look for in the timing? (Not a competant tuner but willing to learn the basics)

[Tjk2world]

How is your throttle cable set? and the screw on the TB

How should it be set? I just have it set so when the pedal isnt being touched, the throttle plate is closed so when i press it it opens. What screw on the throttle body are your talking about? The one to adjust TPS sensor?

[hanzbrady]

I assume that i would check this in my tuning program? My bew laptop is in the mail, but when it gets here what doni look for in the timing? (Not a competant tuner but willing to learn the basics)

You'd check what the engine has for timing with a timing light, base timing should be about 15* but anywhere between 10-20* will generally idle, and the value you see at the engine has to match the value at the ECU, you have to manually sync this by either turning the distributor or changing the tooth angle in the ECU settings.

[Ilya]

You'd check what the engine has for timing with a timing light, base timing should be about 15* but anywhere between 10-20* will generally idle, and the value you see at the engine has to match the value at the ECU, you have to manually sync this by either turning the distributor or changing the tooth angle in the ECU settings.

I still can't believe that people are "building" their engines without understanding what "timing" is.

I'm calling it "The North Korea" approach, sooner or later it will work 50% one hundred percent of the time.

[OnTheChip]

Have you done a compression test?

[JM216S14]

i still can't believe that people are "building" their engines without understanding what "timing" is.

I'm calling it "the north korea" approach, sooner or later it will work 50% one hundred percent of the time.

+10000000000000

[Tjk2world]

Have you done a compression test?

165-167 all cylinders good sir

[Tjk2world]

I still can't believe that people are "building" their engines without understanding what "timing" is.

I'm calling it "The North Korea" approach, sooner or later it will work 50% one hundred percent of the time.

Welp im here to learn! 2 years ago i couldnt tell a nissan from a chevy, literally. It was that bad. Really all i know about timing is that the lower and and upper chain share a sprocket so the crank, pistons, and rods, and work at the same timing at the cams controlling the valves. Also that the distributur shares a chain with the cam sprockets so spark can happen at the correct time.

I assume the CAS relays information to the ecu so it knows when to fire injectors? To be honest I dont know a thing about the ecu side of timing. But im going to look into what the other guy said about matching the mechanical timing with the ecu.

[KAT-PWR]

Take it to a professional

[Tjk2world]

Take it to a professional

Thank you for the positive and motivational words of encouragement!

[thegr8one013]

have you loaded the nemu to work the with the map sensor? put the stock injectors back in and load a map to work with stock injectors. if you dont feel like putting the stock injectors back in, have your tuner come back and try to get it idling. i have a feeling its the tune.

[godrifttoday]

I would first try , the basic , compression test. Then a leak down test. For your tps check if anything changes in the ecu , if your able to monitor it. Try moving the cable to the tps if you get a different reading my messing with the tps ... Well their you go. What type spark plugs? Have you done a boost leak test? You'll be surprise from where you can leak .