s13 sr20det running on two cylinders please help ive tried everything!

[Mass_sr20]

Hey everyone, ive got an s13 sr20det in my 96 s14, i have been going through this for over a year now and dont know what to try next, the sr is only running on the middle two cylinders,
things ive tried...
replaced harness with brand new wiring specialties harness,
replaced coil harness and coils with running ones
tried an ecu out of a running sr
tried an ignitor chip out of a running sr
new cas
new plugs
new injectors
tested both injectors and plugs signal both good
compression yielded 150 on all 4
sealed all vaccum leaks
replaced ENTIRE motor with a sr that was running before pulled
new walbro 155lph fuel pump
z32 fuel filter
reset timing again and again
new chain tensioner

some one please have a simple answer to stop this madness...
thanks!

[DR.EVIL]

ecu change??

[ForeignMuscle]

So the complete harness and complete engine have been replaced and you have the same problem? Something is missing here..

[Mass_sr20]

yea i tried another ecu, im going to try it again just for hahas

[Mass_sr20]

also idk if it makes a difference but it starts right up without hesitation everytime

[BoostWanted]

are the injectors plugs on all the way?? lol.

[Mass_sr20]

are the injectors plugs on all the way?? lol.

yess.. they make the nice *click*

[rotation3x]

Knock sensor throwing ecu in limp mode

[savages13]

Knock sensor throwing ecu in limp mode


That... is just crazy enough. Its equipped with a nistune board so we can disable knock sensing. I believe we've tried it in the past but worth a shot. Better question, how does limp mode work? because the dead cylinders still get fuel and spark..

[Mass_sr20]

Knock sensor throwing ecu in limp mode

Would not having the sensor plugged in cause it to be put in limp mode? The dumb*** who I got the first motor from clipped the knock sensor wires. Luckily the new motor has everything and is plugged in

[Prozac]

While in limp mode you are still going to run on all 4 cyl. all its doing is bypassing sensors and restricting rpm range. So you can limp home. Yes not having a sensor plugged in would cause a limp mode in most situations , with the ecu looking for signal returns.

[Mass_sr20]

While in limp mode you are still going to run on all 4 cyl. all its doing is bypassing sensors and restricting rpm range. So you can limp home. Yes not having a sensor plugged in would cause a limp mode in most situations , with the ecu looking for signal returns.

so.. mine shouldn't be in limp mode sense its running on 2 right? or could it kill two of the cylinders?

[91ka24]

Limp mode is electronical so it not running on all 4 would not be the cause of limp mode. Have u pulled the coils and plugs and run the car, and visually see if your getting spark? If you are, then pull your injectors and see if they are spraying.

[Mass_sr20]

Limp mode is electronical so it not running on all 4 would not be the cause of limp mode. Have u pulled the coils and plugs and run the car, and visually see if your getting spark? If you are, then pull your injectors and see if they are spraying.

Yea I have checked all the plugs and are all firing great and we pulled the fuel rail , and put a piece of cardboard under neath then turned the cas by hand and all are firing correctly

[240sr20de t]

have you checked the injector harness? i had the same problem but when i took the rail out to check if they where spraying they somehow made contact and did spray. about a month later i found two wires completely cut.

[Mass_sr20]

have you checked the injector harness? i had the same problem but when i took the rail out to check if they where spraying they somehow made contact and did spray. about a month later i found two wires completely cut.

Yea i bought a brand new harness from wiring specialties

[Mass_sr20]

Update* I tried a friends ecu (62) and his ignitor neither changed anything besides his ecu wouldn't start my car

[ultimateirving]

What order are the plugs firing in?

[Frank_Jaeger]

Step 1. Sell the car
Step 2. Start over
Step 3. ???
Step 4. Profit

Seriously man, this sounds like some garbage. Did you check the harness with a multimeter?

[Mass_sr20]

What order are the plugs firing in?
I'm not sure I havent checked, I imagine id pull all plugs ground them and see that way?

Step 1. Sell the car
Step 2. Start over
Step 3. ???
Step 4. Profit

Seriously man, this sounds like some garbage. Did you check the harness with a multimeter?
Haha I know I've thought about it but I've dumped to much money and time to bail now

[OrangeVirus1]

Dunno if it is possible on these cars ( but I know this happened on my DSM ) is it possible your cam timing on the CAS is 180* out?

are the CAS's adjustable in any way? ( I have no idea honestly )

[Mass_sr20]

Dunno if it is possible on these cars ( but I know this happened on my DSM ) is it possible your cam timing on the CAS is 180* out?

are the CAS's adjustable in any way? ( I have no idea honestly )

Tried it:/ but yea they're adjustable

[OrangeVirus1]

well there is only 1 thing left it can be then....

Bad car. replace

[steve shadows]

That... is just crazy enough. Its equipped with a nistune board so we can disable knock sensing. I believe we've tried it in the past but worth a shot. Better question, how does limp mode work? because the dead cylinders still get fuel and spark..

Wait I'm confused does the OP have a nistune on the car? Or are you referring to your car?

It could be a problem with drivers on the board but if you swapped the ecu I would still be leaning towards some sort of connectivity issue.

Have you popped the valve cover off to make sure your rocker arms didn't try to escape from under the cams on the exhaust side or something?

What about the chassis harness? Maybe it's not supplying correct power to the ECM/ECU somehow. Sounds like some sort of cross over from USDM S14 Chassis Harness to JDM Engine Harness if you REALLY have done all of that.

Or yeah buy a new rolling chassis and blow the other one up.

[Mass_sr20]

Wait I'm confused does the OP have a nistune on the car? Or are you referring to your car?

It could be a problem with drivers on the board but if you swapped the ecu I would still be leaning towards some sort of connectivity issue.

Have you popped the valve cover off to make sure your rocker arms didn't try to escape from under the cams on the exhaust side or something?

What about the chassis harness? Maybe it's not supplying correct power to the ECM/ECU somehow. Sounds like some sort of cross over from USDM S14 Chassis Harness to JDM Engine Harness if you REALLY have done all of that.

Or yeah buy a new rolling chassis and blow the other one up.
Yea my cars got the nistune but I soldered the jumper back to stock just to make sure, and the harness I bought is made to connect directly to the 14 chassis harness, also I checked all the rockers because it happened once before which I why I re shimmed it

[Mikester]

Try draining your gas and putting some fresh fuel in. Other than that, you can try a different MAFS.

It's prolly something really silly that you are overlooking.

[Mass_sr20]

Try draining your gas and putting some fresh fuel in. Other than that, you can try a different MAFS.

It's prolly something really silly that you are overlooking.

I'm hoping that's the case, ive got a Q45 maf laying around I might try

[Mass_sr20]

So! I tried a different cas... ran on all 4! Problem solved! Thanks for all the help everyone! Now I just need a new cas, anyone selling?