[cstn1987]

Hi, everyone. A few weeks ago I bought a 99 with 50k, to my knowledge stock except for flowmasters. I haven't even pushed it yet and I've been having a blast just cruising around town, couldn't be happier. Until yesterday.

Before I begin, I changed the plugs and wires the day after I got it. Granatelli wires and ngk t5's

Yesterday morning on my way to work I noticed a bit of a rough idle, and sometimes when I'd come to a stop it would start surging and making a grinding like noise. If I put it in park and back into D it stops.I then noticed a surging while driving between 70 and 80 mph on i95.

No loss of power, no codes, and I'd say the surging at a stop happened 2 out of 10 or more stops. Its in general idling like it has a cam now

Freakin out please help!

[sting66ray]

Welcome.
I had a similar situation when I changed out the wires and plugs on my '66 (I know, it's not a C5) and all it was was that I didn't push hard enough on the wire cap on one of the plugs. That was an easy fix for me but since I did nothing else to warrant rough idling, and shitty performance, I figured the connection between wires and plugs had to be the culprit. Hope it helps.

[cstn1987]

Originally Posted by sting66ray

Welcome.
I had a similar situation when I changed out the wires and plugs on my '66 (I know, it's not a C5) and all it was was that I didn't push hard enough on the wire cap on one of the plugs. That was an easy fix for me but since I did nothing else to warrant rough idling, and shitty performance, I figured the connection between wires and plugs had to be the culprit. Hope it helps.

Yeah I did check all the wires, even re did afew I wasn't sure about.. but the problem started about 2 weeks after i did the plugs and wires so its leading me to believe its something else. I guess I'll have to pull the plugs.. hopefully I didnt crack one

[fishslayer143@yahoo.com]

since it started after the new wires installed, I would check your plug wire on number 7... it is very close to the metal tube/pipe from A.I.R. .. mine burned thru and was arcing to the tube causing rough idle and misfires at cruise speed...open your hood at night, you should see the spark jumping

[cstn1987]

Originally Posted by fishslayer143@yahoo.com

since it started after the new wires installed, I would check your plug wire on number 7... it is very close to the metal tube/pipe from A.I.R. .. mine burned thru and was arcing to the tube causing rough idle and misfires at cruise speed...open your hood at night, you should see the spark jumping

Sadly, I've already done that. Checked all the plugs yesterday and they all look fine, wires aren't touching anything. Could this simply be something a good TB cleaning would fix????

Strange thing is I drove it around in the morning after I did all the checks and no problems, went out again in the afternoon and it happened again, 1 time out of atleast 10 stops. strange and If I put it in park and go right back into D it stops.

[vettex2]

Loose/bad engine ground ?

[Hotrod]

Sounds like it could be the MAF sensor.

[cstn1987]

I'm going to try cleaning the maf and the TB, hopefully it does something.. theres a thread on the c4 forums that matches my situation and that ended up being the problem. Thanks guys