WHAT'S WRONG WITH MY 240sx???

[thrusday]

This is the stock engine. I'm planning on getting the SR20DET here in the future, but until then I need this one to at least work until I can afford the new engine..

I've tried everything! I bought my 240 about 2 weeks ago. She ran a little rocky at first, but I took care of a few things.. Here's a breakdown of everything I've done to her since I've gotton her;

New water pumpnew platinum 4 spark plugs and wiresnew distributor capnew beltsoil changetranny oil changenew brakes and calpierscleaned fuel injectors

Here's what she sounds like at the moment;

http://www.youtube.com/watch?v=Y3rbj8VAXt8

Anyways, she was running pretty well right up until we put in the new spark plugs. I know I put them in right, they're not crooked or anything, they're giving off plenty of spark. But after I got all of this done, I took her out for a drive.. The car was idling at about 700-800 rpms at idle and when I went to take off from a stop, the car started shaking really bad and I had almost no power. When I finally got it up to about 3,000 rpms, she lit up. Here's an odd thing. When the car is in park, it idles at around 700-800 rpms, but when I put in in neutral or drive, NOW it will die or choke to the point where it almost dies. This all happened gradually. One day the idling started getting messy, then the next day it got worse, then the other day it sounds and runs like it does on the vid I have on here... I have it tuned to it's hightest to prevent it from dying, but it dosen't help. I've checked the valves and cleaned the fuel injectors, but it dosen't help.

CAN ANYBODY HELP ME OUT?? I'm starting to think it may be wiring or something. The car is grounded and the sensors seem to be alright, but I'm out of options here. I don't know what else it could be..

Any ideas??

[dkdeleon68]

switch spark plugs to ngk

[smokin240]

You might try popping the wires off the plugs and making sure the metal caps that pop on the ends of the plugs aren't damaged, then wiggle the wires a little. But other than that, that's really the only thing you messed with when you did this that could cause that. Unless your plugs are in wrong or something. It may be running so much better since the "tune up" you need to adjust your timing? Also, did you check the plug gaps? Try to make sure everything is tight too. Good luck.

Another thing, when I put my KA24DE in I got the wire combo wrong several times, for some reason it confused the hell out of me. But double check to make sure your dizzy and wires are on in the right order.

[thrusday]

Well, we pulled out spark plugs #2 and #3, there was oil on them.. especially on the tips. We think it MAY be a valve problem..

I hope not..
Modified by thrusday at 10:50 PM 5/7/2007

[Acecool]

Check the injector wires :-)

[thrusday]

Do you know how much voltage or resistance I should get out of the injector wiring/injectors?

[Acecool]

Nope, but make sure they are not corroded, and seated properly.

If you have to, bend the connectors on the inside of the plug a little together.. I did that with mine.

[180fan]

yeah switch to ngk coppers...

[thrusday]

Just did a compression test.. I'm PISSED!! Pistons #1 and #4 at 160, pistons #2 and #3 read 65!!!!!!!!!!!!No oil on the spark plugs, I mistook that for gasoline soaked carbon. I took off the valve cover and torqued all the rocker arm bolts down to 28 ft ibs of torque, but when I was putting the bolts back into the arms of the rockers some of them were stripped.. Not the bolts, the HEAD! So I'm going to get some "Nu-Thread" and see if that will secure the bolts into place..

That's as far as I got tonight.. When I realized that the damn holes were stripped, I put my tools away and came inside.. I'm too pissed to work on it right now...

[tiger]

oh i have been in that ugly boat before.... yea just cool down and don't worry, have you ever heard of helicoils? If that thread stuff doesn't work maybe you could try that.. but it involves drilling...

[thrusday]

Well, I'm not planning on keeping this stock engine for much longer, just for at least a few thousand more miles until I can afford the SR20DET.. this damn engine is just pissing me off. I think my best bet is to go to the junkyard and pick up another head.. I still can't figure out what the hell is wrong with this one as it is... I've tried just about everything!!

[thrusday]

I FIGURED OUT WHAT THE PROBLEM IS!!!

BLOWN HEAD GASKET BETWEEN PISTONS 2 AND 3!



Man I'm so happy it's figured out now.. I've been going insane ripping this car apart trying to figure out what it could have been.. Now I know why it's backfiring, why there's the SAME EXACT low compression in pistons 2 and 3, and why it gradually got worse over a matter of a few days.. That hole in the gasket was just getting bigger and bigger, finally it BLEW!

This is what the engine looked like when I first got it and was replacing the water pump..

And this is what it looks like now..

I won't stop ripping apart a car until I know what the hell is wrong with it.. I'm just glad I figured it out.. Now I just hope I remember where all the vaccum lines go..

But I'm relieved.. I was afraid I was going to have to get a new engine, but thankfully not.. Just wanted to let you all know.. I FOUND THE PROBLEM!!To everyone who might be having the same problems.. Make sure you do a compression test on all pistons BEFORE ripping the head off.

PS...

F**K HEAD GASKETS!

[tiger]

yay u figured it out yeah headgaskets are a b-i to replace.. haha. Well, now you have found your problem!

[Darius]

Your compression test results were text book for a blown head gasket between #2 and #3. Good luck. Hopefully you can get a clean surface for your new gasket to seal against.