BIg Hello to All,

I'm from Singapore, and have owned my 180sx for the past 7 years. Ran the stock CA18det in the early years, then dropped in a SR20det, and now I'm back a full circle with a rebuilt (new oil and water pump, bearings, hone + rings, ARP head studs, deck + Cometic HG) JDM CA18det

I've learned alot from this forum when I was researching about how to go about with the rebuild, so thank you to everyone who shared their experiences.

I'm in the process of running in the rebuilt CA18det. She starts, idles and runs well, and pulls fine without any hesitation. The only thing is that there are random momentary dips in power, these can happen under any situation, be it accelerating, coasting, constant throttle etc.

You can feel the engine stumble and see the rev counter dip, before it picks up again. I believe the problem is electrical as I've hooked up a self made red-green flashy light diagnostic box to my dash - every time the power dips, the diagnostic mode resets itself to Mode 1, so I believe one of the 12V lines going into the ECU is dropping momentarily, causing the ecu to turn off and on.

Another thing to note is that I am running SR20det ignition coils on all four cylinders, as 2 of the old CA coils were faulty. I used the SR coil sub-harness, CA coil rubber boots and used longer bolts with the CA coil pack plastic cover to press/keep the taller SR coils in place, the CA ignitor module is still in use. Internet info about the CA and SR dwell times seem quite close, and this setup seems to work fine, but I'm not sure if this is a source of my problems until I can get a replacement ca18 coils to try out.

Hope to get some views from anyone who has experienced similar issues.
Thank you

I've never heard of anyone with that issue. I would start with grounds. Go through ALL of them, remove, clean with a wire brush, apply conductive anti-seize (like what you would use on a spark plug) and reassemble. When I first brought my S14 home, it started to develop all kinds of random issues. I knew the car had sat for a while, so I just started by cleaning all of the grounds associated with the engine in the way I just described. All issues stopped and it ran better than it did when I bought it.

float_6969 wrote:I've never heard of anyone with that issue. I would start with grounds. Go through ALL of them, remove, clean with a wire brush, apply conductive anti-seize (like what you would use on a spark plug) and reassemble. When I first brought my S14 home, it started to develop all kinds of random issues. I knew the car had sat for a while, so I just started by cleaning all of the grounds associated with the engine in the way I just described. All issues stopped and it ran better than it did when I bought it.

Thanks for the reply Float. Great suggestion to check on something fundamental like the grounds, maybe I'm over thinking all this and just need to get the basics sorted out.

Do you think running the SR coils with the CA ignitor is ok? It kinda runs fine and I did it to get the car through the required annual inspection and back on the road.

For whatever it's worth I had the same problem a few weeks ago only to discover the ground wire for the coils had broken. You could see the thing arcing in the dark when I lifted the hood...

You can never have too many grounds. Never.

I can't comment on the SR coils, but people have used GM coils without issues.

I'm sure the SR/CA coil/driver combination is fine.

dhen wrote:For whatever it's worth I had the same problem a few weeks ago only to discover the ground wire for the coils had broken. You could see the thing arcing in the dark when I lifted the hood...

You can never have too many grounds. Never.

I can't comment on the SR coils, but people have used GM coils without issues.

Hi dhen,

Your comment about the coil ground got me checking on that, but the ground wire was fine. What I did notice on closer inspection was that the SR coils were not seating very well due to just being held down by the CA coil cover, so I re-seated them and made sure they were vertical to the spark plug before tightening the cover down.

This seemed like a step in the correct direction as the misfire count fell dramatically during the 20 minute drive to work this morning (2,3 occasions vs >10 previously).

So yeah it looks like I will be looking for replacement CA18det coils now instead of d*cking around to make the SR ones fit.

Thanks guys for the help

Glad to help, good luck!

float_6969 wrote:I'm sure the SR/CA coil/driver combination is fine.

Just to update based on some more info that I got from the net while researching my problem:

http://www.sxoc.com/vbb/showthread.php? ... ost3804765

As per the above post from sxoc, it's been mentioned that the SR coils need a longer dwell time to charge up compared to the CA coils, so this might be the one of the causes of my misfire problems as well. One more reason to just get the correct coils and call it a day