SR20DET swap problems!!

[luke20]

OK, The swap is about 99% completed. It's a blacktop S13 SR20DET into a 91 240SX LE. The wiring harness (now installed) was sent out to be wired (very reliable person). All electrical components and functions seem to be working. The only problem is that cylinders 2 and 4 aren't sparking. I checked the plugs, they're fine. I switched coil packs with cyl. 1 and 3, and 2 and 4 still won't fire, so I know all four coil packs are good. I even pulled, and grounded, all 4 plugs, and saw only plugs 1 and 3 sparking. All plugs are grounded when in the engine. The engine DEFINATELY is in time -- I've done this before. I have no idea what is behind this problem. I've narrowed it done to: the ignitor chip, the ECU, or the harness. I am unfimiliar with how the direct fire coil/cam angle sensor type ignition system works, as far as what "tells" what to do what and when. I'm familiar with distributor/plug wire types only. I need to determine what sends the plugs their signal, and what sends the plugs their power, and maybe I can go from there. If anyone has ANY info, it will be greatly appreciated. thanks

[sideways180]

get the s14 manual, and start looking for wiring diagrams. maybe your boy who wired the harness screwed something up.  did you pull the valve cover to put your CAS back in?  and is your MAS wired up correctly?

[luke20]

OK, look...The timing is definately right.  I lined the shiny links on the timing chain with the punch marks on the cam gears, matched up the second mark from the left on the crank pulley with the pin on the block, and lined up the CAS before sliding it in.  Once the CAS was in, the orange marked lined up correctly, so I know it's in time.  Besides, even if it were not in time correctly, all four cylinders would still spark, just not at the right times.  I took the plugs out of the motor and saw cylinders 1 and 3 sparking, but 2 and 4 would not.  
What I am trying to find out is what "tells" the plugs when to fire, and what sends them their power.  Does the Cam angle sensor take four readings, one for each plug, and send that back to the ECU, or to the ignitor chip?  Or does it only take one reading, and send that to the ECU?  Do you know that one?  I don't.

[luke20]

Another thing,  the only part of the wiring harness that deals with ignition, and is lengthened, are the CAS wires, right?  I doubt he screwed up on lengthening the ECU wires, that's pretty straightforward...
Another thing--the car ran before, on all four cylinders, untill I removed the harness, ignitor chip, and CAS (to tape the wires, double check the timing, and make it all fit good).  It must've been something I did...

[sideways180]

ok, here's what i can tell you,

A. make sure the computer is bolted into the harness nice and tight.  if it is loose at all, it won't run right.

B. The CAS wiring should not be lengthened.  only the MAS, power steering switch, and O2 sensor really need to be lengthened.  unless he extended the wires to the ignitor chip to mount them.  

C.  here is how the coil packs work.  there should be 3 wires going into each, one is power, one is the signal, and one is the ground.  check and make sure there is continuity between each one and the ground first.  then look for power at each coil pack.  i wanna say the outer two pins on the plugs are the power and ground, but i am not sure.  like i said, get the s14 wiring, it can help you with a little bit of this.  if these both check out fine, then look for continuity between each coil pack, and it's respective pin that runs down to the ignitor chip.  if each one has continuity there, then check for power at the ignitor chip, which it should have since you have 2 plugs firing.  then check for continuity between the ignitor chip and the computer.

D.  the CAS has 2 sensors in it, a 360 degree sensor, and a 180 degree sensor.  it reads these at the computer, sends a signal to the ignitor chip, which in turn sends a signal to the coil packs to fire.  

E.  check all of your grounds

[importrza]

ok on your ka motor you only have 2 coil packs for the ignition, on the sr20 you have coil-over-plug setup therefore you have 1 coil per cylinder. This is why only 2 cylinders are firing. You need to get the wiring pinouts for you car and run the signal wires to the ecu and then you'll be in business (assuming the grounds and power supply are good connections). Hope this will help.

L8r

[importrza]

sorry also forgot that if you did not put the sr20 ecu in then you not going anywhere the ka ecu is not programmed for 4 coils.

[luke20]

first of all--Jay, thanks for your advice.  I haven't checked any continuity yet.  I'm planning to do that today.  You are right about how the wires are arranged for the coil packs.  the middle one is signal, the outer (left?) wire is power, and the other outer black wire is ground.  All the grounds run together to ground on the engine.  All those wires look fine.  

As for importrza--thanks also, but what do you mean by "You need to get the wiring pinouts for you car and run the signal wires to the ecu and then you'll be in business..."   What does that mean?  My knowledge of wiring sucks completely.  Can a bad ignitor chip be behind all of this?

[luke20]

Also, what's a "power transistor" in relation to the SR20 wiring?
I was told that I should check that...the process on how to do that is in the S14 service manual

[luke20]

ok, importrza, you there?

[importrza]

did you get a full front clip? I need some more info to help you trouble shoot. It's not as easy to do this without the car in front of me. Anyways what I am trying to say is: the way you are describing your problem leads me to believe you are still using the ecu for the ka motor.. let me know on this. The reason I say this is because the sr ignition is set up differently than our US version. In the good old US they have two coil packs each of which fires for 2 cylinders. In JDM land they have one coil per cylinder. So.. long story short if you have all the wiring correct and are using the US ecu then 2 of the coil packs are not recieving a signal to fire. I don't think you are having a problem with CAS. If the CAS if 180 off you should be getting spark, but just not in the right order. You can check the ignitor chip, but first start with the basics before you really start ripping anything apart. A faulty ground could be the cause but I highly doubt that;it is unlikely(but not impossible) that you coincidentally only have 2 cylinders firing. Let me know if this doesn't help, I'm located near detroit if your near I could take a look.

[luke20]

OK, first off--thanks for your help.  I appreciate it.  Here is some more info for you:
The car is a 91 240sx le 5 speed.  
The engine is an S13 blacktop SR20DET ('97 ish)
The ECU, engine wiring harness, CAS, and ignitor chip are all from the SR20.  The only thing re-used was the KA trans. wiring harness.  
My theory is that the problem is either in the wiring, or the ECU.  Since cylinders 1 and 3 are firing, and they are in different phases, the CAS is probably working correctly, right?  If it f--ks up, then usually only cylinders 1 and 4 or 2 and 3 will fire, because they are in the same phase.  
I've also been told that if the ignitor chip was bad, no cylinders would fire.  
Cylinders 1 and 3 fire at the correct times, always, so this is not a timing problem.  
So, there.  I think I've ruled out the CAS, the timing, and the ignitor chip, that leaves the wiring harness, or the ECU.  Does that all sound right to you?  Let me know.  
BTW, I live near Pittsburgh, PA.  :-(
thanks for your help.

[SR20DET S14]

try asking at sr20.hybrids.jp they seem to knw a sh!t load about sr20det's

[mini-x]

sorry to bring back this old thread, and yes i did SEARCH. i am having the same problems. only getting spark in cylinder 1 and 3. ive changed the ecu, igniter chip, cas, checked all the grounds, checked continuity, and have went through all the wires on the harness and am still having this problem. so does anyone have any idea that might fix it?

[nassin31spr]

Are you getting a signal from the ecu and ignitor for the non firing coils. Did you switch the coil packs. Is your timing 100%. Take a multimeter and start tracing down the problem.

[mini-x]

i did switch the coil packs around and all of them do work. timing is 100% dead on. i did use a multimeter and found that the coils are not getting a signal. ive checked the harness and everything to see if there were any frayed wires touching, and there wasnt any.

[nassin31spr]

Check for a signal on the ecu side of the ignitor. If no signal then your ecu is burned up. If you have a signal on that side then check the other side of the ignitor and if you have no signal though the ignitor, then you have a burned ignitor. You doing the right stuff you just have to keep going back though the system to the ecu and you will find the culprit.

[mini-x]

i think i might have found my problem but can anyone please verify that this is the right ecu pinout for a redtop s13? http://datnet.org/techinfo/page1.html