"Stumbling" at low RPM.

haseebgill12 · Post by **haseebgill12** » Tue Jul 17, 2012 10:28 am

Well I have an 02 r/t and its been acting weird ever since I got it.

Problem 1: At low RPM's particularly 2nd gear the car stumbles and "jerks" a bit. However, as soon as the RPM's pick up the car seems to be fine and power delivery is smooth.
I have replaced the coil pack, wires and plugs with NGK Iridium's but it still seems to do it.

Problem 2: Possibly related to Problem 1. Today when I went to start my car, after about a week, the car "stumbled" on start up and the dials fired up all the way to the end on the RPM and Speed gauges (however the engine didn't actually rev up like that). Then when the dials were returning to normal they stopped at one point then settled at where they should be. This seems to be a random occurrence as the next time I started the car it started fine, but the time after that it done the same thing again.

Problem 3: There seems to be a low metallic rotational grinding noise which increases slightly when I accelerate in 1st and 2nd but is inaudible at higher speeds (3rd gear+) I jacked up and inspected the front right wheel (I couldn't remove the wheel due to this:
viewtopic.php?t=63254).

I spun the wheel and could definitely hear a slight grinding noise which came and went as the wheel spun round. What could this be? I have a feeling its the rotors. The brakes are also really spongy, as I have to floor them to make the car stop slowly.

I need urgent help, Thanks in advance.

Post by **occasional demons** » Tue Jul 17, 2012 12:25 pm

Hmm, got a volt gauge to see how low the volts go when cranking? You should get a battery light for low voltage, or a CEl, but if the volts are too low, it might cause the driveability issue.

A warped rotor would make that noise.

haseebgill12 · Post by **haseebgill12** » Tue Jul 17, 2012 12:32 pm

I do have a voltmeter, but I don't have a CEL or any codes. Plus the battery looks pretty new so I wouldn't think it was that.
Would a bad TPS cause the driveability issues? It's really pissing me off because I don't want it to be something serious.

Post by **occasional demons** » Tue Jul 17, 2012 2:09 pm

Well the cluster gauges/dials going whack is a sign of low voltage. That's what's steering me to the voltage issue.

It may be a bad connection, or ground giving you problems. Check all your fuses inside and out for tight/clean connections too.

haseebgill12 · Post by **haseebgill12** » Tue Jul 17, 2012 6:06 pm

Ok thanks, I will have a look tomorrow. Can you please suggest what would cause the low RPM stumbling? I forgot to mention that the car also seems to have a bit of a "whine", which increases as you accelerate.

gcretro · Post by **gcretro** » Tue Jul 17, 2012 7:55 pm

Sounds like the classic low rpm issue when in drive and stopped.

haseebgill12 · Post by **haseebgill12** » Tue Jul 17, 2012 8:17 pm

gcretro wrote:Sounds like the classic low rpm issue when in drive and stopped.

Well it's a manual, could you please elaborate?

Post by **occasional demons** » Tue Jul 17, 2012 11:20 pm

It's not the classic severe vibrating/rattling when in drive at idle issue.

Haseeb's issue is another ball game.

Since the coil, and injectors get their power through the ASD relay, I would check the relay contact, or swap it out with one of the other relays.

I would check/clean the ground near the left head light as sitting in the car.

Checking all the other grounds won't hurt either, but it is a place to begin.

I'm betting for some reason you are not getting full voltage to certain things at lower RPM's.