Rough KA24E at idle and moderate acceleration

[jerryk]

I just picked up a second red 90-240SX hatch(new). I plane to use this car as the body and my (old) red 240SX as the parts car. Everything in my old 240SX is running perfectly the engine has 210K and I have owned and taken car of it all these years. The problem with the old car is the underbody is almost completely gone and that is the reason for the (new) car. The plan is to take the best parts from each and create one car. Both cars are stick and have the same colors. The only difference between the two is the (new) car has ABS, which I plan to dump.

Problem:The (new) car engine with 175k, which I was thinking of keeping, is very rough at idle it is also rough when you accelerate moderately. I had a compression test and the results are posted below. I checked out the plugs and they were clean. I changed the oil, plan to change the rotor wires and plugs but I do not think this will help. I am not sure that the problems are related. What should I look for next?

Nissan 1990 240SX Wet and Dry Compression test CYL 1 CYL 2 CYL 3 CYL 4DRY 155 156 155 158 12.90% 8.97% 13.55% 13.92%WET 175 170 176 180

Remember my (old) car can be used for parts.

[WWJD]

check the connections on your injectors, MAF. Also if you IAV or IAA are dirty they will do this. I sea foamed my car, then hand cleaned the IAA (the thing under the master cyl. forgot the name of it right now) the car idles better and runs smooter. Another thing you should look out for is the little black box that sits on it, mine had a hole in it so I just hooked up the hose from the air box straigh to it.

[whiplash willy]

Check your injectors, I had similar issues and when I pulled my injectors, they had brown crap in them.

[spindrift187]

plan to change the rotor wires and plugs but I do not think this will help.

When I first got my current motor running it had very little power, and would spit/sputter at WOT under 3500rpm then free rev like normal. I changed my distributor cap and rotor button and it completely fixed my issue and car pulls very well now. Dont overlook the small stuff

[WWJD]

good job. Hey I just tryed a new spark plug gap .44 and car runs smoother. give it a try and see what your think