rpms bouncing

[swampthing]

this started about a month ago, when my car is cruising and it gets to a hill that's steep enough that it goes into positive boost to climb it sometimes the rpms will bounce around and make the car jerk, if I hit the gas it will downshift and stop doing it. i do not think that this is a misfire since I have no codes stored and because i can floor it when it's doing it and it doesn't have any problem going. it will also do it if I am just coming off a red light and slowly coming up to speed when the tranny shifts early into 3rd it starts bouncing around and I have to give it gas.


all i have tried so far is changing the maf with a spare I had laying around, it seemed to help but then last night on my way home from work it did every symptom exactly the same.

any suggestions would be greatly appreciated

[gweg_b]

I'm no expert on this, but several years ago, my Buick LeSabre would do the same thing. It was pretty much guaranteed to happen every time I climbed a hill. Turned out that my EGR was bad. It didn't set any codes, so I originally wasn't sure what it was. Someone told me to check the EGR. Replaced it with a spare I had lying around, and the problem never came back.

I guess that would be something to look into.

[swampthing]

swapped in a spare TPS yesterday and it seemed to help. I've only had one instance of something similar and that was it coming out of lockup and downshifting up a steep hill with the cruise set.

stupid question: where is my EGR and how difficult/costly is it to replace?

[gweg_b]

Here's where the EGR is on the SSEi's, the cylinder just behind the throttle body, and next to the transmission dipstick:



If it's anything like on the Series I, it's just held on by 2 nuts and the wire connector, so it's pretty easy to change. As for the cost, I'm not sure, as I had a spare from a torn down L67 I had lying around. Probably a few bucks for one from a junkyard, but I would figure it'd be up there for a new/re-manufactured EGR from an auto parts store, and even more from a dealership.

Hope this helps out a little.

[01bonneSC]

Around 100 bucks.

[Mystical-Myst]

Just as a side note to this pot my rpm gauge was doing the same thing as well and then it just suddenl went away. I'm not sure if it just fixed itself or something like that lol

[1fatcat]

Same thing happened to my girl friends car. Was a bad PCS in the trans.

[spoiledred94]

I am not getting a clear enough picture of the symptom. stalling upon acceleration? And no codes? Something I didn't read mentioned: bad gas/clogged f filter. My 94 SE egr was $75, didn't solve the problem...it was the cc servo setting the code.

[swampthing]

it's not really a stalling its more of a jerkiness under light throttle the rpm's do not bog they bounce upwards, i am beginning to think it has something to do with the tranny going into lockup and acting strange.

Same thing happened to my girl friends car. Was a bad PCS in the trans.

that's what's starting to worry me. it's not shidting hard but it does seem to go into lockup a little early. a question for you 2000+ guys if you set your cruise at 45 on a level road what do your rpm's say?

[bonneville dan-o]

i had the same problem forever! i replace the TCC solenoid the PCS and it helped for about 1000 miles then came back. new maf sensor, plugs, fuel filter didn't help either. i went to the tranny shop and they said my torque converter was going out. i put in a tube of torque converter shudder stop and the problem went away. then came back about 4000 miles later. i then flushed, and changed my filter and added the shudder stop again and it has been fine. it still seems to lockup early though. there wasn't an unusual amount of debris in the pan. i changed the plug wires and it helped a little more.

I'm going on a trip to Texas this tuesday. 3000 mile round trip. hope it makes it

my mom has a 99 regal LS that did the same thing, so she bought an 03.... that too has the same problem... now were stuck with two! i put plugs and wires in both of them and they haven't done it since. but the 99 hasn't been driven much since.

[01bonneSC]

I think when this problem starts happening your trans is gettin toast, im waiting/saving for a rebuild.

[swampthing]

ok given that this sounds like the converter I have a game plan. I just did a fluid and filter change about 3-4 months ago. I am gonna do another one using transtune before, with dex VI and two qts of lucas. and we will see how it goes from there.

this may take a few weeks to do since I am broke right now

[repinS]

Bringing this thread back, I've been doing some searching on an EGR issue I've been having.

I too have had a low throttle studder, present BOTH before and after a recent transmission rebuild. It tends to happen coming from a stop, or with light throttle in lockup. It's killing my city mileage because I have to stomp on it a bit more to get off the line.

I'm OBD1.5, but I'm occasonally getting an EGR valve position error code. I pulled off my valve (two 1/2" nuts) and cleaned it (hopefully S2 can do the same) with some throttle body cleaner. Took about 10 minutes and preliminary driving suggests that the shudder is gone. I'll know more after driving around, and it may just be a temporary fix, I don't know if it'll come back, requiring EGR valve replacement.

I know you're worried about the transmission, but you might as well try the free solution first. Worst-case scenario, you're out a few bucks for a can of TB cleaner that you'll likely use down the road anyway.

[bonneville dan-o]

i've been having the same issue off and on with my car. and it recently threw a code for the EGR valve. but i haven't got around to replacing it.

my question is.... how on earth does an EGR valve have anything at all to do with my rpms bouncing under light load in lockup???

this whole time i thought it was a trans problem... so did the trans shop.