CA running on 3 cylinders

[ELV-iS]

So got the engine in the car going but its running shite

misfiring shaking left and right on idle - calms down a bit higher up the rev range but still not running right....

anyway after spending a feckin age looking for vacuum leaks - I've narrowed it down to cylinder two not doing anything...

basically I can unplug coil two and it runs (nearly) the exact same...


what I've tried so far...

there is no vacuum leaks
changed coil pack harness
changed coils
changed plugs
earthed coil harness to battery
checked and getting spark on all 4 coils
getting fuel to rail
getting fuel in injector
changed 2nd injector anyway
all four click
tried different ecu
tried different cam sensor
played with ignition timing (kinda makes it better or worse but nowhere near where it should be)
I did the timing belt before the engine went in - took cover off and factory marks still line up
Did diagnostics using the led on back of ECU - 5 red / 5 green "no fault code found" on both ECUs - cunt

at one stage while it was running I unplugged nearly every sensor one by one and all it does is a little fart and keeps running the same way - won't start with maf unplugged... this has a lambda sensor old engine didnt - tried both ECUs with and without lambda plugged in - no difference........

its got a t28 and walbro now but fairly certain that has nothing to do with it


its got 110psi compression in cylinder 2 - which is low and I know its low but from what I've read online there's people rocking around with CAs for years with around 100 across all four.
Cylinder 3 has the same compression, if I unplug the coil it dies so that's why I'm thinking its not compression. The engine isn't great I know its got 140/110/110/130 cylinders 1-4 but I still think its strong enough that I can drive it till I get the cash monies together for a fresh one...


anyway.... any ideas ?


put an SR into it they said....................

[ELV-iS]

Should add to this.... cylinder 1 is not the best either... and thats the one with highest compression? wtf

unlugging coil from:

1 - a little bit of difference in how it runs
2 - no noticable difference
3 - struggles to stay running
4 - struggles to stay running


Runs fairly well on two cylinders tho

[Tomas_s13]

which loom and maf are you running? as you said old engine was non lamda and his one is, non lamda maf will have 4 pins on it and loom of the same wont have the pins for lamda sensor on the main ecu plug and map on the ecu itself is different to lamda one which will have only 3pins on the maf and all needed pins at ecu, engines themselves have no difference in between lamda/non lamda its just ecu+loom+maf that differs- just something to check, other bit to check would be you tps, counting that your cas is set right, as half moon yoke in the cam likes to brake leaving you with messed up timing.
did you try to swap cyl1+2 coils with cyl3+4 and see if the effect of engine not reacting to unplugging coils 1 and to moves over to cyl 3 and4?
and is that 4 port or 8port head?

[slithertooth]

Oh 8 port ca head!! Now were talking Nissan's haha. Not heard that for some years!!

[ELV-iS]

I'm using the 3 pin maf and lambda engine harness

Cutting the spare coil loom now to connect 3 into 2 to check if the issue moves onto cylinder 3

This might be a stupid qs but how can I tell if its a 8 or 16 port head ? Like is there any external visual differences or numbers ?

[Tomas_s13]

ha ha! ye rory thats the real engines
elvis- ya dont need to cut nothing! just swap coils over on loom as is and try to unplug them then just to see if the problem isnt the coils themselves! 1 port head ha! no man its either 4 or 8 ports, you can tell the difference from outside looking at the intake manifold, 8 port head will have 8 ports going into head 1 for each valve and will have butterfly flaps controlled by vacuum, so it should be vacuum controler at he back of the manifold

so if ya using 3 pin maf and lamda loom make sure to use lamda ecu as well as other one is mapped to run with no lamda and based on maf+tps readings only

[ELV-iS]

I've tried different coils problem is always with no.2

Just changed the ignitor aswell just there still the same

Have a lambda and non lambda ecu not sure which is which goin google it now and leave the lambda one in it but it runs the same on both with cylinder two missing. ..

Don't get how ecu isn't giving a fault with the amount fucking around with sensors I've done..

[ELV-iS]

Actually runs a bit worse on lambda ecu and you can can hear it backfiring into intake aswell if that means anything

[ELV-iS]

Took a video earlier... this is on the non lambda ecu... with the lambda ecu its a wee bit worse but the mad misfire and shake is still there..

http://youtu.be/f4YrsrgkMpQ

Oh and Tomas not sure why I swapped the coil plugs when it was going to run like a pig anyway.. thought you were saying that and I was ready to try anything.. cars nearly all back together and I haven't driven anything rwd in months I'm goin end up on heroin if this doesn't run..

Do you think its worth a shot trying the non lambda engine loom and ecu ? If I can find it...

Something I thought of earlier... I'm using the non lambda cars interior/body loom... There isn't any sensors inside that are different and would cause this ?

[Tomas_s13]

Dude drugs are bad for you.... so I was told at school but on serious note- interior loom will make no difference, r you sure that the timing is correct? That missfire sounds like the belt is not lined up right