When Will the Pain End ?!

[TachyonS14]

Ok, I have a 97 240sx and since I've had It, It's always had a vibration problem. The vibration Is engine related and causes vibration throughout my dash and my steering wheel. It seems to really vibrate around 2krpms. So, I've gotten new spark plugs, plug wires, O2 sensor, cap and rotor, air filter, fuel filter, cleaned the throttle plate (which was very dirty btw) all new motor mounts (left, right, and transmission), I also ran Seafoam through the gas tank, crank case, and brake booster line and yet my problem remains!

The only person I've seen on here with the same type of problem is S14Life In this thread http://www.nissaninfiniticlub....48430

Ok, so today I busted out my Chiltons and It said rough Idle and virbrations could be caused by 1) Clogged air filter 2) Dirty/Bad Gas or 3) Bad fuel pump. I think I've narrowed my problem down to fuel since I've done everything with the ignition/spark. Now, do you guys think that replacing my fuel pump or injectors might fix the problem? I feel that maybe one injector is bad and not spraying enough fuel which causes the other injectors to go out of wack and making my engine not run like it should. Or, my fuel pump is bad and Is not pumping enough fuel to my injectors? What do you guys think?

[Ambivalent]

Hey there,

Sorry, I dont have an answer, I just wanted to say I have the same problem....I just got my 240 last week so I was little concerned, but it seems to be a common problem..... I also get the "rattle" when I m at full throtle. I m not quite sure where its coming from since I m doing 140+Km/h and cant be bending down to listen........ :P

It is very annoying though, and the vibration in the steering wheel is uncomfortable........

Cheers

[TachyonS14]

Help me end my pain !

[karay240]

before you start spending money on a new fuel pump, I'd say get a new fuel filter. The 300zx fuel filter fits with hardly any modification, and will give you better throttle response (especially after you mod the car more). If you're not sure about buying a new filter, try cleaning out the one that's on your car. If that doesn't help it, then get the fuel pump, but no point in spending money on a stock part =)Save that money and get a part that actually makes the car better.

[TachyonS14]

[quote=" TachyonS14 So, I've gotten new spark plugs, plug wires, O2 sensor, cap and rotor, air filter, fuel filter, cleaned the throttle plate (which was very dirty btw) all new motor mounts (left, right, and transmission), I also ran Seafoam through the gas tank, crank case, and brake booster line and yet my problem remains![/quote]

I've already done the fuel filter

[crazee240sx]

First of all...Car and Driver reported that the Nissan 240sx was "a affordable supercar, but we hate the vibrations that roll throughout the car and into the steering colomn" so.....Welcome to Nissan 240sx! But if the vibrations are greater than a little shaky, try the motor mounts! rev the motor using your thumb to push the throttle cable and watch the drivers side motor mount. Engine lift too much? Theres the problem! Or transmission mount.

[TachyonS14]

[quote=" TachyonS14 So, I've gotten new spark plugs, plug wires, O2 sensor, cap and rotor, air filter, fuel filter, cleaned the throttle plate (which was very dirty btw) all new motor mounts (left, right, and transmission), I also ran Seafoam through the gas tank, crank case, and brake booster line and yet my problem remains![/quote]

I've already done the motor mounts... Hooked on Phonics worked for me!

[TachyonS14]

Would a bad alternator cause this kind of problem?

[allthrottlenobottle]

isnt there a balancer on the crank pulley?

[TachyonS14]

You mean the harmonic balancer?

[sleepyRPS13]

does it only vibrate at 2krpms or does it continues beyoned that?

[allthrottlenobottle]

ya harmonic balancer, i was thinking it might be that.

[TachyonS14]

does it only vibrate at 2krpms or does it continues beyoned that?

To answer your question yes. 2krpms is seems to be when it really starts. At higher rpms it's less noticable, but still there. The vibration causes all kinds of rattles and it's driving me nuts!

[hotshot240sx]

to be honest buddy...does sound like a fuel problem...if the car is vibrating roughly and is kind of stumbling along...u may want to check the resistance on your injectors...and even check the adjustment on your valves...rattles and vibration are hard problems to figure out....and to be honest u may never get rid of it...but u are on the ryte track...and if u feel its a fuel problem then take a shot at the injectors...and even look for a vacuum leak...take sum carb cleaner and one by one hit those lines...but i strongly suggest u check ur injectors...if one or more is acting up...u will feel the problem especially as throttle increases...what happens is that the engine starves for fuel and will stumble along...feels like a ratical vibration and even engine stall motion...other then that...check if u a have a service engine soon lamp on ar a check engine light...and pull the codes...

[TachyonS14]

No check engine light, so no codes. But I'm going to test the fuel pressure in the lines. So, I might try a new fuel pressure regulator if the pressure in the lines is low. Then new injectors, and if that doesn't work, fuel pump.

[Meantime]

I have a stupid idea, but here goes nothing.

Do you guys still have the factory catalytic converter heat shield attached?

After about, oh, 4-5 years the heat shield tends to get pretty beat up and it makes this ugly, nasty vibration/rattle around 2-3k RPMS.

Check that out as cheap insurance - I had the same vibrating problem on my '90 and '91, removed the heat shields on both and viola, no more rattle.

Don't know if that's related to your problem, but figured I would throw it out there as a possible culprit.

[TachyonS14]

My friends civic made a lot of rattling noises and we found out it was the heat shield for his cat. But could It cause actual vibration inside the car? I'll give it a try!

[cory2081]

how many miles are on the car?? does it vibrate when in neutral with the car stopped and the engine revving?? or only when driving??

[TachyonS14]

120k, and If I put It in neutral and rev, It will still do It. I'm going to start off with a new fuel pressure regulator. I have a gauge to test the fuel line psi, but It only goes to 10psi and my readings need to go up to 43 psi. Autozone wants like $45 bucks just for the gauge, and thats like the price of the regulator. So new regulator here I come.

[DGA]

It sounds like one of your injectors is not 100%. My '91 did the same thing when I got it, but my injector went belly up in 2 weeks. Easy way to figure this out. While your car is running pull out the spark plug wires from the engine, one at a time. Your car will not die it will just run very rough. Do this one cylinder at a time till you find the one that ruins your idle the LEAST. Even if it turns out that this does not do anything one way or another, at least you will rule out the injectors as a problem. If you isolate the cylinder that is misbehaving, pull out your injector and see if the rubber gasket is bad. Even if it has a little tear in it, it will ruin your performance, and they are only about .50 cents a piece. Also if you isolate the problem to a certain cylinder, compression test the engine/cylinder to make sure that you do not spend $130 on a fuel injector that is running well.

[cory2081]

Does your car still have the mechanical fan?? Sometimes the clutch goes bad on them and could cause a vibration.

[TachyonS14]

WOW, thanks DGA! I'll give It a shot. I highly doubt one of my plugs is dead, and not working at all as I have plenty of power from my motor. Maybe one is really clogged, and I should run another can of SeaFoam through. And cory, I thought of that too but It works just fine.

[cory2081]

I'm just trying to throw everything out there that I can for ya man. It could also be a worn pilot bushing, is the oil level ok? Is the engine running smooth (no missing or studdering)?? It could be a problem with the clutch as well, maybe the pressure plate threw a weight?? (doubtful) The harmonic dampener in the front of the crank pulley may be bad (rubber deteriorated). Does it do it less when the clutch is engaged/disengaged??? Hope some of this helps man.

[DGA]

Your spark plugs are probably good, but your fuel injector is probably going bad. This test assumes that your ignition system is in good operating order. It helps you isolate the problematic cylinder. If you know that you have good spark, only things that can go wrong are your fuel supply (your injectors in this case), or that your problematic cylinder is going bad. Try this and tell me what you find out.

My injector #2 was going bad over a period of a few weeks, and it started with just a little shake at idle, till it completely went bad, and I was running on 3 cylinders. These engines are very tough and will do 80 with one cylinder being completely dead. Lots of shaking though. Good luck.

[DGA]

Oh yeah, have you checked your timing?