Stutter at Constant Steady Speed

MelFeliFJ · 09-29-08, 11:38 PM

I have noticed lately when driving on a flat highway at a constant speed I will every once in awhile feel a slight stutter/surge/hesitation. Its not the feeling of gears shifting but it almost feels like I drove over a small bump on the road. This happens randomly and at times it will also do this while accelerating going uphills when depressing the gas pedal at one spot. Does anybody have any ideas? I'm sure the dealer will be no help because they will say they can't duplicate it. Just seeing if anybody else experienced this.

MarcoPolo · 09-29-08, 11:45 PM

No answers here...

..just makin the rounds

Welcome to MUD

Good Luck

DEWFPO · 09-30-08, 02:21 PM

I have a somewhat similar issue at exactly 35 mph. The trans keeps shifting back and forth with the slightest touch of the pedal, the feeling is very jerky. If I stay off the gas or lock it into 4th, it does not do this. I think that my conditions, flat terrain, very light, occasional throttle input, constant 35 mph and high altitude are conditions the engineers didn't predict in the AT's programming so it gets confused.

DEWFPO

joebob2586 · 09-30-08, 03:06 PM

MT or AT?

knoll0351 · 09-30-08, 03:10 PM

I have found that the computerized AT feels "funny". After several trips to the dealer I now feel much more comfortable that it is just the way the tranny was designed to opperate.

MelFeliFJ · 10-01-08, 01:53 AM

Mine is an A/T. Maybe it is normal. I have heard that Toyota engines takes time getting used to. The thing is I haven't noticed it doing this before. Do you think it could be Spark Plugs?

joebob2586 · 10-01-08, 08:17 AM

how many miles are on the truck?

1911 · 10-01-08, 08:38 AM

Quote:

Originally Posted by MelFeliFJ

Do you think it could be Spark Plugs?

No; I have changed mine religiously at 30K and 60K miles and the old ones always look just fine and there is no difference in performance with new ones. Besides, if it were the plugs it would do it at all speeds not just one certain rpm.

MelFeliFJ · 10-01-08, 12:08 PM

I'm approaching 25K. I wonder if having the defroster on would cause this?

NYCTRD · 10-01-08, 12:49 PM

Quote:

Originally Posted by MelFeliFJ

I have noticed lately when driving on a flat highway at a constant speed I will every once in awhile feel a slight stutter/surge/hesitation. Its not the feeling of gears shifting but it almost feels like I drove over a small bump on the road. This happens randomly and at times it will also do this while accelerating going uphills when depressing the gas pedal at one spot. Does anybody have any ideas? I'm sure the dealer will be no help because they will say they can't duplicate it. Just seeing if anybody else experienced this.

The AT is controlled electronically and does some seemingly strange shifts that are designed, in part, to "down shift" when on a grade. This is likely normal, but it never hurts to mention to the dealer and if you don't have your own code reader (Scan Guage, etc.) so they can check for error codes.

MelFeliFJ · 10-02-08, 12:56 AM

I will probably take it to the dealer and have them check it out. I guess it wouldn't hurt.

knoll0351 · 10-02-08, 04:30 AM

How old, how many miles and how much wheelin'?

MelFeliFJ · 10-02-08, 09:25 AM

I have about 25K and not much wheelin lately. I'm wondering if has to to do with the Flex Lockup/Torque Converter.

Quote:

Originally Posted by knoll0351

How old, how many miles and how much wheelin'?

joebob2586 · 10-02-08, 12:27 PM

I had a problem with my FJ a while ago the steering would intermittently bind up, took it to the dealer and like you said they couldnt duplicate the gripe, so i asked one of the mechanics to ride around with me so i could show him what I was talking about, they found the problem and fixed it under warranty...so you might as well give it a shot since you do have a warranty use it.

MelFeliFJ · 10-08-08, 10:28 PM

I took my FJ to the dealership. There were no codes or anything. They say it could be my AC compressor and if there were any problems my Check Engine Light would light up.

DEWFPO · 10-08-08, 10:43 PM

Quote:

Originally Posted by MelFeliFJ

I took my FJ to the dealership. There were no codes or anything.

That's not unusual and it does not indicate there isn't a problem.

Quote:

They say it could be my AC compressor

Nope, I never feel mine come on or off

Quote:

and if there were any problems my Check Engine Light would light up.

Not necessarily so.

Sound's like they couldn't replicate the issue and gave you the standard "go away-it's normal" slop.

Go test drive a new one and see if it behaves differently under the same conditions.

DEWFPO

joebob2586 · 10-09-08, 06:47 PM

did you ask them to go for a ride with you so you could point out the problem when you felt it?

MelFeliFJ · 10-10-08, 10:48 PM

Yes he rode with me. And I definately feel it more when the defroster is on. I may test drive another and see if it acts the same. I guess as long as it is documented then I should be covered. Hopefully......

jsknockoff · 10-12-08, 06:38 AM

Sounds like the same thing mine is doing. The trans is staying in the same gear but it feels like driving over a rumble strip for a second. Mine usually does it when the truck is in a lower rpm range going up hill. Thought about taking it to a dealer also but figured it wouldnt do it for them so Im waiting for it to get worse.

MelFeliFJ · 10-12-08, 09:03 PM

What do you mean by a rumble strip?

Quote:

Originally Posted by jsknockoff

Sounds like the same thing mine is doing. The trans is staying in the same gear but it feels like driving over a rumble strip for a second. Mine usually does it when the truck is in a lower rpm range going up hill. Thought about taking it to a dealer also but figured it wouldnt do it for them so Im waiting for it to get worse.

powderpig · 10-13-08, 06:10 AM

In defroster mode, the a/c compressor is cycleing on and off. Maybe the compressor is dragging the engine a bit when you are at the speed you are. Thus the engine is trying to catch up to the sudden load of the compressor. This would also happen when you have he A/C on as well.

MelFeliFJ · 10-14-08, 12:04 PM

Yes, that is pretty much what the dealership is saying. It seems to be doing it more when the defroster is on.

Do you guys know if it is true that when there are problems with the tranny/engine will that trigger the check engine light? This is what the dealership is saying.

DEWFPO · 10-14-08, 12:22 PM

Quote:

Originally Posted by MelFeliFJ

Do you guys know if it is true that when there are problems with the tranny/engine will that trigger the check engine light? This is what the dealership is saying.

Sometimes, not always. It depends on the problem. Example : A fellow FJ'er had a bad torque converter and the problem was physically noticeable but no codes were set either with the ECM or TCM.

DEWFPO

Bluester · 10-15-08, 07:33 PM

What about fuel filter or vapor lock?

larsdennert · 10-28-08, 12:53 AM

Dirty MAF? That affects 3rd Gens quite a bit.

MelFeliFJ · 10-29-08, 01:23 PM

They didn't even look at the MAF. I don't know much about cars so I'm not exactly sure what I should have them look at. I would think they would automatically know what to look for. I guess it is documented and hope that if something turns out breaking they will take the responsibility of fixing it.

larsdennert · 10-29-08, 02:14 PM

Mass Air Flow Sensor. It can be cleaned with electronics cleaner or replaced at a cost. When dust (from wheeling) gets in the sensor it doesn't read correctly and throws off the air fuel mixture.

In short, a wire gets heated to a specific temperature and the air moving through the sensor cools it. The more and cooler air that is flowing, the more power it takes to maintain the temp. The computer calculates from this how much fuel must be added to get the correct mixture. Dust on the sensor confuses the computer into thinking there is less air so it adds less fuel. You then get a lean condition that causes the motor to stumble at constant closed-loop throttle positions.

OlyWaFJ · 10-29-08, 02:51 PM

Water in your transmission.

EXACTLY what mine was doing... I was able to work it through insurance and only cost me my deductible, it is a non-warranty issue. If insurance doesn't cover it then get your check book out to the tune of about $3k-6k depending on if you go used, rebuilt or new.

My dealership missed it the first time around too...

Good luck, hope I'm wrong!

MelFeliFJ · 10-31-08, 01:05 AM

Definately should not be any water in the tranny. I rarely go through water.

rusty1 · 10-31-08, 05:20 PM

Hi all
I too have the same problem with my fj. Its new only 250 miles on it and it shifts especially if I go around 28 or 29 mph. I did not take it to the dealer yet but will in the near future. would like to know if anyone ever got the problem fixed.
Thanks Rusty1