Engine Surges on 2000GT

Got a problem I can't figure out. My car surges when going up hill. I though it might be the transmission but it does it in both drive and overdrive. I changed the spark plugs and wires (they were due anyways) but the problem is still there and getting worse. Typically oscillating between 2000-2500 rpm. Step on the gas and it goes away. Acceleration is still good and revs up to 6000 rpm without a problem.

Anybody else have this problem?

By the way it is a 3.8L engine.

Is there any specific speed that it does it in? How about any service engine lights? And how is the idle quality?

Idle quality seems ok. No engine codes. Does it at around 30mph while going up hill in drive and 50 mph in overdrive.

when mine did it, it seems to do it around 55/60 mph.

Mine seems to do it around 46/47 mph, a bit of an acceleration, seems to want to pick up speed moreso than before that speed, is this bad?

I don't know if I would completely rule out a tranny problem. With all the sensors and OBD-II it's a pain trying to find problems without a scan tool that pulls up live data. Anyway, there could also be codes that don't request a MIL lamp, or transmission data that could be helpful. Sorry I can't be more helpful.

The best I can do is on Monday check on any TSBs about that problem.

I'm going to put my scanner on it this weekend to see what is going on. Don't really know what to look for cause I assume that without a check engine light, that there is no codes. What you are telling me is that there may be codes generated anyways? Thanks for your help 86TATpi.

Yeah, stupid trouble codes. Had problems with the GTP, finally got a SES lamp but there was only one code that had a MIL lamp request. The other didn't trip it. Look for transmission codes as well as engine codes. If you can get the live data you would be able to see exactly what the engine is doing when it surges. Sometimes you have tools that can freeze data so you can review it.

Got a problem I can't figure out. My car surges when going up hill. I though it might be the transmission but it does it in both drive and overdrive. I changed the spark plugs and wires (they were due anyways) but the problem is still there and getting worse. Typically oscillating between 2000-2500 rpm. Step on the gas and it goes away. Acceleration is still good and revs up to 6000 rpm without a problem.

Anybody else have this problem?

By the way it is a 3.8L engine.


I have the exact same problem as you have described. No service engine light either. The only other thing mine does is when you try to reset the change oil soon light, the light just keeps flashing continuously and wont stop like it is supposed to. It goes out and stays out after you turn the key back off but it just wont reset properly. I was thinking it may be a throttle position sensor problem since the oil light reset uses this too. If you have fixed the problem on yours please let me know what it was if you would.

Thanks,
Greg

Yeah, stupid trouble codes. Had problems with the GTP, finally got a SES lamp but there was only one code that had a MIL lamp request. The other didn't trip it. Look for transmission codes as well as engine codes. If you can get the live data you would be able to see exactly what the engine is doing when it surges. Sometimes you have tools that can freeze data so you can review it.

Scanned for codes tonight and got zilch. Also found out that my scanner only gives codes and no data.

Told by a mechanic that it could be the solenoids in my transmission. Still not sure though cause it happens in both drive and overdrive.

Very strange. Have not noticed problem for a while. All I did was wiggled my spark plug wires.