Not sure if SC threads here are dead yet but I figured I’d try!

I have a 1995 SC400 I’m building to drift. I’m swapping the A340 with a CD009 via the Collins kit and I got as far as putting the flywheel and clutch on and figured before I put the transmission in I’d check starter engagement. The engine cranked over no problem but to my surprise, it did not start... NO SPARK! I read on other threads that all you need to do to the factory auto harness is jump the NSS via the black-black/white wires and the two green wires for reverse lights. An important note: I didn’t want the factory harness to end flopping around under my car if my cable ties broke/melted so I cut the entire harness off near the rear of the engine, spliced NSS and reverse wires and capped the rest to prevent the issue. I’m not sure if this is causing my issue or if there was supposed to be a voltage reference from the trans that the ecu needs to see to allow spark? Idk I’m stumped... the car ran perfect before the swap. (Although it has been sitting for about 4 months.) Battery is charged and good, fresh fuel and stabilizer has been added, checked the ECU capacitors; good. Checked plugs, wires. Has new ig coils, new distributor caps and rotors. Igniters tested good. I’m sure I’m missing some things I tested.. Please help!!!!

 

Oh ya, and after jumping the NSS I have no neutral light on the dash. I do t think this is normal either?

 

i bet it has to do with u cutting the stock harness off and "capping it off" lol or ur igniter randomly died. My cars a factory Manual i put an r154 in and so i havn't dealt with what your doing

 

Thank you for the reply. Yes I thought maybe chopping the harness could have something to do with it but I figured since all the plugs will not be used (open circuits) I would shorten the harness and hard wire needed wires. Assuming wire colors didn’t change. There were no in-line relays or anything so at the time I thought why not.

 

if NSS isn't on, the car won't crank at all, so if it's cranking the NSS isn't the issue and something else might be.

 

So the black-black/white wires don’t control the neutral light on the dash? I’m also wondering if my ECU, plugs, wires, coils and igniters are all good, why am I not getting spark? Crank position sensor? Across the two terminals I got a resistance of 5 M ohms. I can’t find the spec anywhere. But I also read somewhere the ECU gets crank position from the distributor caps.

Thanks for the feedback boys

 

The open isnt going to do anything besides maybe set a code. if wires are cut and short together jumping circuits that could be bad.

As long as the connectors on there then the pins and wires should never be able to touch.

 

5Million ohms...? thats like an open. you want like 5 ohms 50 ohms something like that. just google the Pins of the ECU for our car and youll be able to see where everything goes and comes from its old enough everythings out there

 

Alright ive got the wiring diagrams for you off TIS. I forgot you had an sc400 and stuff isnt as common.

From looking real quick its the second pic top right and you would want to ground the Light blue Neutral wire but i'm just guessing.

 

 

resistance for cam and crank sensors should be 900-1200 ohms i think, or maybe it's k ohms. one of those, if you're seeing something way above or below that you got bad sensors. first though check the wiring on both the cam and crank sensors, it usually gets chewed up by the serpentine belt.

the NSS does not turn the neutral light on inside the cluster, it allows the starter to crank. the position of the gear selector changes the lights on the cluster. since you don't have that anymore you won't see any PRNDL lights on. is your fuel pump turning on? ECU won't send spark without fuel pressure. Try jumping pins FP and B+ inside the diagnostics box by your intake manifold and see if you get spark then.

 

I failed to mention before that I’m getting code 12. No physical damage to the cam sensor wires. Although I could see where that would be a problem; The Right side looks like it’s been repaired before. Left side cam sensor tested 1.06 K Ohms. The right side tested almost the exact same. Crank position sensor read 4.4 M ohms across the 2 terminals. Fuel pump only runs with the jumper wire and Still no spark with the jumper hooked up. I ended up ordering an eBay crank position sensor. 🤷🏻*♂️ The sensor should be in on Monday.

 

yea sounds like it's the crank sensor, car won't even try to start if that's bad. i had the same problem except mine was worse, all the wiring was destroyed and the sensor read like 4 ohms, so completely closed circuit somehow.

 

Update: My crank position sensor came in last night. After replacing that, she fired right off! So excited I can finally continue with the swap! Just gotta hang the trans, put in driveshaft and bleed the clutch. Should be running and driving by this weekend!

 

good to hear! we're doing the same swap this saturday too.