RPM oscillate when idle!

lifesnotfair · 01-11-2006, 12:08 AM

Hey all,

My revs kinda oscillate when I'm idle. When I turn A/C they kinda go up a bit, to about 1000, without it it goes down to about 700-800... but they kinda dance in there, ya know... and it's not just a bad tachometer coz you can feel it in the car actually.

I know I have an escape somewhere in the exhaust (maybe the exhaust manifold gasket or I don't know what), and a mechanic told me it could be the spark plug wires.. he even told me those wires don't even seem like the stock ones on my car, because the tips of them don't go all the way "in" the head... What's a good set of wires for me to order? I changed all the spark plugs a week ago.

stumpjumper · 01-11-2006, 03:14 AM

Check the throttle positioning sensor, it's on top of your intake manifold. This happened on my 3vze and it was the TPS. I'm sure you can find one on ebay for about $10.

lifesnotfair · 01-12-2006, 04:46 AM

My mechanic was right, with a quick view he thought it was "missint spark" at idle. Lol, dunno how the heck he knew that, but changing the wires helped.

I was gonna get performance wires, but saw those MSD ones at 90 bux on 935motorsports. Plus shipping, plus having to wait at least 2 weeks with that damned problem that was shutting my car off at idle sometimes. This set was only 39 bux. I reckon they must be of a cheap brand, but hey, for that amount, I should be greateful they're at least new! =P .. Been spending a lot on car recently, and I'm still desperate to buy the entire 89+ moulding set and lower the car. I got my momo hub adapter and some crappy steering wheel is on the way, hope it gets here soon. I'll take pics after all of this, so some can see the progress it's been making. =)

stumpjumper · 01-12-2006, 06:24 PM

SO it's working properly now?

Cheap wires are alright unless you plan on running heavier upgrades. I put a set of Belden wires on my 7m and they are pretty thick, at 7mm. I had never heard of them before and they seem to work just fine.

lifesnotfair · 01-12-2006, 07:07 PM

Yeah, it doesn't "cough" anymore at idle rpm.

I might use better wires too if I ever decide to do major upgrades.. but my engine is N/A and I don't think there's much I'm gonna do to it. When I decide that I want real power, I'll buy a new engine, either a 7M-GTE or a 1JZ-GTE. But I wont do that for now. Right now I just want the car to look clean and run nice.. =)

01-11-2006, 12:08 AM	#1
lifesnotfair 3" Exhaust Join Date: Oct 2005 Posts: 169	RPM oscillate when idle! Hey all, My revs kinda oscillate when I'm idle. When I turn A/C they kinda go up a bit, to about 1000, without it it goes down to about 700-800... but they kinda dance in there, ya know... and it's not just a bad tachometer coz you can feel it in the car actually. I know I have an escape somewhere in the exhaust (maybe the exhaust manifold gasket or I don't know what), and a mechanic told me it could be the spark plug wires.. he even told me those wires don't even seem like the stock ones on my car, because the tips of them don't go all the way "in" the head... What's a good set of wires for me to order? I changed all the spark plugs a week ago.

01-12-2006, 04:46 AM	#3
lifesnotfair 3" Exhaust Join Date: Oct 2005 Posts: 169	Hrm.. My mechanic was right, with a quick view he thought it was "missint spark" at idle. Lol, dunno how the heck he knew that, but changing the wires helped. I was gonna get performance wires, but saw those MSD ones at 90 bux on 935motorsports. Plus shipping, plus having to wait at least 2 weeks with that damned problem that was shutting my car off at idle sometimes. This set was only 39 bux. I reckon they must be of a cheap brand, but hey, for that amount, I should be greateful they're at least new! =P .. Been spending a lot on car recently, and I'm still desperate to buy the entire 89+ moulding set and lower the car. I got my momo hub adapter and some crappy steering wheel is on the way, hope it gets here soon. I'll take pics after all of this, so some can see the progress it's been making. =)

01-12-2006, 07:07 PM	#5
lifesnotfair 3" Exhaust Join Date: Oct 2005 Posts: 169	Yep. Yeah, it doesn't "cough" anymore at idle rpm. I might use better wires too if I ever decide to do major upgrades.. but my engine is N/A and I don't think there's much I'm gonna do to it. When I decide that I want real power, I'll buy a new engine, either a 7M-GTE or a 1JZ-GTE. But I wont do that for now. Right now I just want the car to look clean and run nice.. =)

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01-11-2006, 03:14 AM	#2
stumpjumper 3" Exhaust Join Date: Dec 2005 Posts: 74	Check the throttle positioning sensor, it's on top of your intake manifold. This happened on my 3vze and it was the TPS. I'm sure you can find one on ebay for about $10.

01-12-2006, 06:24 PM	#4
stumpjumper 3" Exhaust Join Date: Dec 2005 Posts: 74	SO it's working properly now? Cheap wires are alright unless you plan on running heavier upgrades. I put a set of Belden wires on my 7m and they are pretty thick, at 7mm. I had never heard of them before and they seem to work just fine.