Here's the deal. I'm new to Nissans BTW. Decided that trying to get power out of an Accord was futile so I found a deal and went for it.


1990 240sx SOHC/KA24E project car/beater. Base model 5 spd, no fancy HICAS or anything like that. Starter only works 1/500 the time (Def. need a new one, but thats not the big problem). It is low on oil, and what is in there is extremely dirty. The radiator also appears to be pretty low. I put in a new air filter, got new spark plugs, going to get a new starter next week, also thinking about a new distributor, basically overhaul the entire ignition system.

The problem is insanely hard starts. I had the hood open and the engine jumped a good 3-4 inches left and right. The shifter also jumps pretty hard. It also sputters a little and tries to die if you dont immediately give it gas. Once you give it a little, I revved up to 3000 and held it there for a few seconds, the idle stabilizes. It dips a little now and again, but stays steady. The engine itself sounds OK beyond the hard start, just needs oil and injector cleaner, and a full tune up. No serious knocking or rattles, just normal sounds for an old engine. Could it just be the knock sensor or some other sensor? Loose mount?

I know the rod bearings can give it problems, but what would a spun bearing sound like? Would it cause hard starts?

 

Follow up....

Ran some Gunk brand engine cleaner through, runs much smoother now. It still has a nasty sub-1500 RPM shudder, but anything over that is stable. What could cause that?

 

well not to sure but my old cars motor use to jump when i started it and when i shifted. I jus replaced the motor mounts and the problem was fixed.

 

Suspected that.

What about the shuddering?

 

Well im no mechanic but sounds like a few things, check all the connectsions on ur MAF it could be that, otherwise it could be a faulty injector, and then check the fuel pump.

 

Mine was pretty rugh on idle and I noticed the first injector wire was messed up and next to that there is a sensor(I think it's a red connection. That one was bad also.

 

Could be your AIV flowing the wrong way, messing up your idle, in fact if you've replaced your plugs, 02 sensor, fuel injector cleaner, clean throttle body, MAF cleaned, replaced fuel filter, i'd be willing to bet thats it.

Dr.

 

My engine is been kind of jumpy also, every one of two times when I start the car, the engine jumps violently, but it runs fine and steady other than that...how can I check for bad mounts??? They are hard to get to them as it is.....


thanks

 

If you have bad mounts they will be pretty obvious-dried out, cracked, falling apart, visibly rotted away.