92 240sx shakes in all gears

[rightbrainnow]

Hi, hope im posting in the right place. I own a stock 240sx...just a normal point A to point B daily driver. Sometimes, more often than not, the car shakes violently up to about 3000 RPM's. Once I exceed 3000 RPM's the feel kinda evens out. At idle the car shakes...gear shifter vibrates heavily. Go into any gear...vibration until the top of the gear. I took it somewhere and they told me it was a driveshaft issue and wanted to charge me 900 dollars. Went to a junk yard and got a driveshaft for 13 bucks and put it in myself. I then test drove it, vibration was gone (i think this was just a coincidence). The next day it started happening again. On the way to work at the top of 4th gear i felt something kind of "lock" in place and the car stopped shaking all together for the next few days. Confused, I decided to push the car up to about 80 mph to see if the problem was actually magically resolved. Sure enough, doing this made the problem come back. I realized that the mechanic I showed it to was probably an idiot considering that the car shook at idle...how could it be the driveshaft? The driveshaft just sits there and does nothing at idle, right? Im thinking that its maybe a motor mount issue. Any ideas? Where are the motor mounts? I am not car savy.

[MRNA]

I'm thinking your right about the motor mounts, happened to my wife's Mercedes and thats what it was. For a daily that you're not gonna push you can just try some from a yard or hockey puck it - http://www.driftopia.com/2007/...ounts

[dickie]

from skimming your issue it sounds more like a dead injector causing the car to run on 3 cylinders, thereby misfiring and causing the car to "shake."

my car did the EXACT same thing with this issue, it would balance out above a certain rpm and drive more smoothly, but still be running on only 3 cylinders. the fact that it happens at idle rules out the driveshaft. if it were motor mounts it wouldnt be intermittent.

what you need to do is let the car idle and unplug one spark plug wire at a time moving from the front to the rear replacing them as you go. if the idle gets worse, you know that cylinder is good. when you pull a wire and the shaking doesn't change, you know that cylinder has no fuel, spark or compression.

try it and post the results here.

[rightbrainnow]

This makes sense. Do you suggest i get new wires etc as well? I went outside and started the car with the hood open. I could definately see the engine come to a "stand still" when i upped the RPM's in neutral. I looked under the car (as much as I could) and the entire exhaust system is shaking as well...seems like this is doing a lot of wear and tear on the entire vehicle. Would you recommend to not drive until i get this fixed?...or is this not that big a deal.

[rightbrainnow]

from skimming your issue it sounds more like a dead injector causing the car to run on 3 cylinders, thereby misfiring and causing the car to "shake."

my car did the EXACT same thing with this issue, it would balance out above a certain rpm and drive more smoothly, but still be running on only 3 cylinders. the fact that it happens at idle rules out the driveshaft. if it were motor mounts it wouldnt be intermittent.

what you need to do is let the car idle and unplug one spark plug wire at a time moving from the front to the rear replacing them as you go. if the idle gets worse, you know that cylinder is good. when you pull a wire and the shaking doesn't change, you know that cylinder has no fuel, spark or compression.

try it and post the results here.

Ok, cylinders 2-4...the shaking changed. Cylinder 1, there was no change at all. Again, im not very car savy....what are you suggesting i change or repair?

[Cone Junky]

Now you have established that the misfire is on cyl 1. So you need to pull the spark plug and check the resistance of the plug wire. Hopefully it is just one of those two items, since they are cheap, readily available, and easy to change.Unfortunately there are many other possibilities. It could be a bad injector, injector wiring, low compression, bad valves/lifters.

Good luck

[rightbrainnow]

Ok, changed the spark plug and the wire. The old spark plug was filthy and gapped way too wide. This did not solve the problem, though. Seems like the shake changed, but did not go away. Next thing to try? Fuel injector? Is this difficult?

[addisonblck]

ooo...damn was it covered in oil......carbon?wat was it cover in...? lol sumthing important to no.

[xekushnr]

Yeah, d!ck's got it right, definitely a dead cylinder. Now that you're sure its not an ignition problem (unless its the dizzy, could be a worn breaker point) you just gotta make sure that fuel is going to the cylinder. The easiest way to test this is to pull the injector out, keep it hooked up, grab a empty water bottle and have a friend start and run the car for a few seconds while you shoot gas into the bottle. You want to make sure that fuel is coming out (obviously) and spraying in an even fine mist. I wouldnt recommend that you put that gas back in your tank unless the bottle was COMPLETELY dry before, because there will be some water left in the bottle and I'm sure you know that water does not compress.

[rightbrainnow]

Yeah, d!ck's got it right, definitely a dead cylinder. Now that you're sure its not an ignition problem (unless its the dizzy, could be a worn breaker point) you just gotta make sure that fuel is going to the cylinder. The easiest way to test this is to pull the injector out, keep it hooked up, grab a empty water bottle and have a friend start and run the car for a few seconds while you shoot gas into the bottle. You want to make sure that fuel is coming out (obviously) and spraying in an even fine mist. I wouldnt recommend that you put that gas back in your tank unless the bottle was COMPLETELY dry before, because there will be some water left in the bottle and I'm sure you know that water does not compress.

Ok, so i bought some fuel system cleaner (techron) and some carb and throttle body cleaner...and an air filter, but thats neither here nor there. Anyways, after both cleaning treatments the shaking has gone down i'd say....30-50%. However, the tehcron didnt unclog anything. I was going to try and pull the injector out like you said and test it, but the screws are so corroded that they stripped in about 2 seconds...so now im off to figure out to get those off.

[rightbrainnow]

Ok, so I did some testing. I pulled out fuel injector 1 (where the dead cylinder was)...dipped it in some gasoline, cleaned it off, and then swapped it for fuel injector 2, from cylinder two (which was working). Started the car, no shake at all. Drove around the block, felt a dead cylinder kicking in and out (it wasnt doing anything at all prior to my amateur cleaning). Got back home, got the rough idle again. Did the spark plug test, this time there was change in shake in cylinder one (a sign that the fuel injector is good according to prior post in this thread). Tried cylinder two and no change in shake at all. So the problem followed the fuel injector....this means that its absolutely the fuel injector thats the issue RIGHT? Also, I lost the metal washer (o ring?) that went on top of one of the fuel injectors. I've still got the rubber bushing thing that goes on top of it...how important is it that i have that washer? I found this http://www.partsamerica.com/Pr...PTSet=but i dont want to spend 9 dollars for one tiny odd shaped washer.

[dickie]

if the problem followed the injector, that means the injector is at fault.

if you purchase a new injector for $90 at most parts places you will have everything you need to put it in, including the o-ring (the tiny rubber band that goes around the tip of the injectors on the fuel rail side).

alternately, used injectors can be had or spare parts from other people's cars for much cheaper. you run the risk of buying a faulty part, however.

[leveloneae86]

ooo...damn was it covered in oil......carbon?wat was it cover in...? lol sumthing important to no.

lets say the spark wire tip is covered in a gooey material. it seems like its oil. what would that mean? sorry for the thread jack back im in the same position

[brandonDavid]

lets say the spark wire tip is covered in a gooey material. it seems like its oil. what would that mean? sorry for the thread jack back im in the same position

it means you got