highway shakes!

[muhammedmian]

I'm not too sure what the problem is but I have a hunch it's the fuel filter? I have a 90 automatic.

For the past three months or so, I've been experiencing a shaky/quivering/jumpy ride on and off, here and there but now the issue is persistent.

The Problem:

When driving on highways, at/around 2400-2500 RPM and 50-55+ MPH, when I accelerate. The car shakes back and forth like there is no fuel, or it could be anything. It's like if I put the car in neutral at 55 MPH, and then suddenly accelerated, and then put it in neutral again. This is my description of the shakes since there are a lot of different kinds. The car shakes back and forth.

The reason I think it's the fuel filter is because when I first experienced this issue, a buddy of mine told me to use 89 gas. I did exactly that and the problem completely disappeared. Now it's back and gas Is not correcting the issue. Logic tells me that this car was negelcted and it must be the fuel filter since 89 gas temporarily fixed the problem.

Anyone want to chime in?

[sonikaccord]

These cars have so low compression that 89 shouldn't have made a difference, but since it did:

Check your plugs
Check your ignition timing

Those are the easy things I can think of right now

EDIT: you have an automatic. Are the gears slipping? , or is the engine stuttering?

[muhammedmian]

It feels like the engine is stuttering. Then again, 54-60 mph is when the car shifts into fourth gear accoording to the AT FAQ.

[Theos92VR4]

I had an issue with my car doing the same thing. I wound up checking my spark plugs to find they were covered in oil. so i changed

Plugs
Wires
Spark plug tube seals (under rocker assembly)
Valve cover gasket
Distributor cap and rotor

Then the problems went away, and hasnt come back since. BTW my car is manual trans and was doing it.

[muhammedmian]

That's great news. I do have some oil that shows every other week out of the grommet closest to the oil fill cap. There must be an underlying problem because I changed my VC gasket for the same reason and the leak is showing up four months later, but not as severe. I'll look into the plug later today, I saw some oil on the bottom of the shank.

[muhammedmian]

I'm noticing that it's not so much the speed but the RPM. I was just doing around 35 MPH and tried to speed up quick and every time the tach was around 2500 RPM - it just kept dropping to 2000.

Do you gentlemen still think its the same issue?

[Raf99]

This could be many things. You need to start narrowing down some things.

Check the plugs, etc as the other guys mentioned.

- Any check engine lights?
- Does hot or cold make a difference?
- Is it total loss of power or does it "spit and sputter"?


Fuel filter would most likely do this at ALL higher RPMs (say anything about 2K). Sounds like its not. This would also remove fuel pump as the problem.

I think you may be looking at a O2 sensor, MAP, or IACV too

[Fleetw00d]

I'm noticing that it's not so much the speed but the RPM. I was just doing around 35 MPH and tried to speed up quick and every time the tach was around 2500 RPM - it just kept dropping to 2000.

Do you gentlemen still think its the same issue?

Is the transmission shifting to the next higher gear prematurely? This would drag the engine speed down? Put the transmission in 3rd, then try to accelerate from 35 mph (this should prevent it from shifting to 4th if that is what is happening).

[muhammedmian]

Okay, so it looks like I am only having this problem in the 4th gear at high speeds. I drove in 3rd gear on the way to work this morning well past 50-55 MPH and the car was fine - no stuttering. Then I moved the shift selector to D4 and I felt the transmission shift into 4th gear at 40 MPH, gradually accelerated past 60 MPH without stutter.

I am finding that the stutter only occurs when I am:

> 2500 RPM
> 50-55 MPH
in 4th gear

[Losiracer2]

since its transmission related, try a drain and refill of Honda ATF and see if the problem improves. If it does, then you'll have to do it a couple more times to get the entire system cleaned out of the dirty fluid since I believe its at least 8-10 qts full of ATF.

[muhammedmian]

I would say the issue is definitely intermittent since it comes and goes. Back in November when I first experienced it, I immediately did a drain and fill (once) and didnt notice any change. I still have 1.5 q left so I might do it once again.

Update:

I just changed my plugs and wires (after a long hard day of OT) and found the following.
cylinder#1 - oily! (This is near my leaking grommet and I am suspecting a correlation)
cylinders#2-4 - dry but white and crusty


Hopefully I'll notice a difference but I am also cleaning the IACV tomorrow

[Fleetw00d]

Oily on the firing end of the plug, or just on the top of the plug and wire? Sounds like you should have done at least a valve cover gasket if not lower tube seals while you're at it.

[muhammedmian]

looked oily on the firing end but then again there was oil in the socket running down. I'm noticing that when I start the car, it wants to stall. I give it gas and all is well. What gives?

Edit: from what it seems, the shakes are gone! (For now?) Can plugs and wires really affect the ride of a car? I thought all plugs and wires did was start the car.

[muhammedmian]

Here's an update for anyone searching on this topic.

After changing plugs and wires (ngk v power& ngk blue wires), the problem went away.

I also cleaned my iac valve and throttle body, adjusted fitv, and replaced the fuel filter. This was the first time I performed this kind of maintenance for this car since I accquired it and Im noticing a huge difference! It really does make a difference.

[Fleetw00d]

looked oily on the firing end but then again there was oil in the socket running down. I'm noticing that when I start the car, it wants to stall. I give it gas and all is well. What gives?

Edit: from what it seems, the shakes are gone! (For now?) Can plugs and wires really affect the ride of a car? I thought all plugs and wires did was start the car.

I hate to say it this way, but do you understand how an internal combustion engine works? The spark plug in each cylinder fires (voltage delivered through the plug wires) every other revolution all the time the engine is running. If one is not firing correctly for whatever reason, the engine will run rough, particularly under load (like accelerating from a low engine speed in a high gear); and that rough running will be felt in the car.