I'm getting seriously frustrated. Sr20 wont fire

[landins13]

93 nissan 240sx with red top sr20, i blew up my motor rebuilt it and put everything back together, i am not getting a spark at all, engine will not fire. I was told before to check my wiring, my ignitor, and my ECU. I pulled the entire wiring harness re did it and re-installed it, i replaced my ignitor, i replaced my ECU. I am still not getting any spark, and the engine still does not fire. does anyone know the voltages for the power wire and signal wire at the coils and does anyone know the voltages my CAS should be recieiving and putting out.
Thanks, Landin

[SoSideways]

Get a hold on an S14 w/ SR20DET FSM... everything's in there...

[NemeGuero]

You should get a KA.

Distributors rawk.

[SnakeKack]

^^ I agree NemeGuero.

[Vision Garage]

Hahaha. Unhelpful bastards! :) Grab a multimeter and trace where the power is going and where its not going. Maybe your cross some wires wrong.

[unicoladron]

there is also a diagnostic procedure you can use by connecting LEDs to your ignition (somwhere near coilpacks) then pulling your CAS, turning it by hand, and seeing if the LEDs flash. someone chime in if they know what i'm talking about. i know i didn't make this up. the procedure may be in the electrical/ignition section of the FSM. this will determine if you have a bad CAS. it could also be your ignition wiring, i remember hearing of issues with that.

[landins13]

ive checked all of the wiring, the car was running without a problem until it blew up, none of the wiring was changed, and i removed all of the wiring once i started having this problem and inspected it for problems. The wiring is good. I'm having trouble getting a hold of a repair manual, if you have any sites or suggestions let me know. and the procedure i think youre talking about would be using a timing light, but that wont really help me with getting a fire, unless im thinking of something different. I really appreciate the insight, if you have any other suggestion please let me know.
Thanks again, Landin

[onyxaltezza]

Timing? Distributor?

-Aaron

[johngriff]

Take out the cas, spin it. Are the injectors clicking?

Test continuity from the ignitor chip plug (ecu harness side) to the ecu. Test the coil pack harness the other way. Do this by using a resistance test, if the resistance is too high, I am guessing its bad.

Um, Check for power on the injector wires. If no injectors + no coil packs, probably a bad egi relay.

[unicoladron]

Timing? Distributor?

-Aaron

his SR20 doesn't have a distributor, it uses a camshaft position sensor.

but i swear there was some other procedure..but now that makes me thing of something else. i'm still stuck on the CAS, because it's the only part of your ignition system you haven't tested. here is a procedure from the FSM, the procedure i was thinking of was for injector pulse i think...oops. but here try this maybe:
http://i198.photobucket.com/albums/aa231/unicoladron/cas.jpg

is your mechanical timing in spec?

how do you know you're not getting spark? did you crank the engine with your coil packs out with an extra spark plug and hold it ~1 inch from your valve cover and look for an electric pulse while cranking?

[unicoladron]

ahhh! did you check your ecu for codes too!? if you haven't yet, check now!

[johngriff]

It is not sparking.

Its also not going to generate codes until it runs probably..

[WISH ONE]

Im getting sick of my sr also! bELIEVE ME! i have a similar problem, fuel spark and to my knowledge timing is there, but no firing at all. anyone wanna buy an sr set up lol. good luck keep us posted.

[mestizo]

THis may sound like an obvious and stupid comment but did you check your fuses and grounds?

[WISH ONE]

check your cas?i tested it the first time and all the injectors seemed to pop fine when i spun it on second look i finally figured out why mine wouldnt start i tore my cas apart and the metal disk inside had a little hole burned out of it.

[landins13]

ok so here is the update. all of my wiring is good, i pulled the entire harness again and rechecked its all good. I havent checked my CAS but i have a slightly larger concern after talking to a friend of mine that is a master tech for mercedes. he listened to it turning and said it almost sounds like im getting not compression, so tomorrow im going to compression test it. Ive done the ignition spark test as described above, i finally found a FSM for my car, its for an s14 but hopefully it will help me with my redtop. Um as far as anything else....ignitor is new, starter is new, ECU is new, i also have a mines ECU (IN CASE ) oh im definitely getting fuel, my timing is perfect, im just kind of at a stand still, i'm feeling like its gotta be something with the coils and/or the CAS hopefully its something simple cuz those are both expensive and im really not trying to give up on this thing. My fault though, i was making stupid power on stock internals and i ran the motor almost dry so yeah.

I appreciate all the help guys really, ill keep updating with any news.
Thanks again, Landin

[landins13]

forgot to mention, i checked the fuses and grounds. Sorry, ive done a lot in the past few days plus work, school, snow, flu, im pretty sure ive lost my mind.

thanks, landin

[mxsx25]

if your deffinately getting fuel, than that means the cas should be good, ohm test your coil packs , and is your igniter BRAN new or just bran new-second hand lol could be faulty... i had sorta the same problem for a while, and it ended up being both my cas and igniter

[hstylez]

Recheck grounds. I had no spark when I didn't have a ground on my valve cover...

[cotbu]

Its also not going to generate codes until it runs probably..
Good save!

I say. if it's not an obvious problem, reverse engineer it! Look at all the things that would cause your car not to start under normal circumstances.

Also you must mean mechanical timing is perfect, because you haven't started the car yet. What was the results of the compression test?

Pop in the other ecu to maybe eliminate an ecu problem. I'd really like to hear the sound it makes when your trying to start it.

I also have a shit load of tests that I would have you do, but that's just redundant at this point.

Continuity test the harness would be #1 before the ecu swap.

[johngriff]

Sounds like it has no compression? You would know.

Fuel + Spark + Compression = Run. Its got to be one of those 3.

[blownmotor]

you probably could have flooded the combustion chamber from all those times of cranking pour some oil in to each cylinder before you crank it next time see if your ignitor is getting any power from the ecu and power coming out of the ignitor

[WISH ONE]

I havent checked my CAS but i have a slightly larger concern after talking to a friend of mine that is a master tech for mercedes.


... make sure you really check everything, i had 3 nissan master techs a stuck on why mine wasnt starting, they all looked right past the cas issue. good luck with the comp issue

[OfourTHREEfive]

Any update on the status, I hate unfinished stories :(

[Chrischeezer]

Sounds like it has no compression? You would know.

Fuel + Spark + Compression = Run. Its got to be one of those 3.

Yep... check compression buddy...

[blu808]

You know the cas has to be set on a specific tooth right?

If it is off the car wont run.

[mxsx25]

cas and/or igniter... had the same problem... swapped em and started right up

[blu808]

good going man. Hows it run?

[landins13]

the car still isn't running, ive gotten kinda side tracked with my 280z. I need to check the compression still, as well as the coils, ignitor is good, im getting fuel, the CAS is in the proper location according to my FSM the only things left that i can think of are the coils and the compression, i made the mistake of loaning a friend my multimeter so i need to get that back. Until then there wont be any updates, i mean in the time ive been waiting on things i lowered the car, started measuring and fabricating my cage, i got my hands on a set of Hayashi racing wheels from the 70's they are the ugliest things ever but i love them lol, they are only 14's but they weigh less than 10 lbs each the fronts are 14x7 +13 offset and the rear are 14x9 +22 offset, they should look obnoxiously good with some drag radials on them

[landins13]

i didnt see the question about the ignitor until just now, sorry, im running a z32 ignitor and it is brand new, i got ignorant special ordered it from advance auto parts, swapped it with the one i had and returned that one and told them it was the wrong part and got them to refund me.

im real close with the manager and thats what he told me to do so its w/e, lol i spend so much time at advance that i have a commercial account with them.

[landins13]

so for those of you who have been helping me out, i know i said i wouldnt have an update for a while, but i figured out whats wrong, i snapped a camshaft in half. i have no idea how, but the engine had no compression because nothing in the head was turning, the intake cam snapped clean right where it attaches to the cam gear. im in the process of taking off the head to check and see if i have any bent valves i probly will, and at this point im thinking about buying a new head so if you see one let me know (dick tracy) i really appreciate it.

Landin

[slider2828]

Did you follow torque procedures in the FSM? Only real way to snap the came, but if you cranked it with the valve open, you can be assured of a bent valve. Better safe to rebuild the head seriously or break it apart and chek all of the valves.

[Big Bronze Rim]

Yup, I would say 99.999% of the time a broken cam is due to install error. Sucks to hear. You probably need to pull the head to check for bent valves.

[GuardianLlama]

You probably need to pull the head to check for bent valves.

Sr's are interference motors?

I didn't think that they were.

but I'm still a :newbie:

[jskateborders]

Sounds like it has no compression? You would know.

Fuel + Spark + Compression + Air + Timing = Run. Its got to be one of those 5.
.fixed it. . . . . .

[landins13]

heads off, now bent valves, how the hell this happend i have no idea im still trying to work things out.

[slider2828]

You probably didn't torque the cames center outwards like FSM. THe cam snapped, and the valves stayed down or open. You cranked the car and the piston's slapped into the valves hence bent valves. Since you know you have bent valves, you might as well rip the entire engine out as you probably will have nicked the pistons a little or just really clean on the bottom end...

[Big Bronze Rim]

Sr's are interference motors?

I didn't think that they were.

but I'm still a :newbie:
It is. And the OP unfortunately has bent valves to prove it. Time to build the head and upgrade cams! You MUST follow the proper torque sequence or broken cams WILL be the result.

[landins13]

i did follow the proper torgue sequence and had them torqued down properly, i was bolting down the trans when my buddy reassembled the head, and he flopped the cams, he had the intake cam on the exhaust side and vise versa. the head is toast, im buying a whole new one.

[Gjohnson7]

So, I assume you and your buddy are going half on a new head???:smash:



Well, lesson learned. Next time you make sure you handle the most important part and tripple check your work.