My 2003 SLE with 181,000 miles has a stumbling hesitation problem. It has been going on since 135,000 miles but seems to be getting worse. It has updated plugs, wires, fuel filter. intake gaskets, etc. I put this out to the forum couple years ago and since have checked fuel pressure, cleaned coil bases and changed catalytic converter. Now it seems to be getting worse. I am trying to focus in so here is what I know. I drive 15 miles to work. the first 10 is no problem. After that it seems to miss and stumble at all speeds under load. No engine codes. If I stay real light on the gas things are fine but if I try to move a little faster seems like it is missing an jerking especially up a hill. Great running vehicle otherwise.

So on the way home from work I messed around to see if I could really make it worse. Med to heavy throttle between 35 and 60. Car was really surging. Almost like I was fluctuating the gas peddle. Finally threw a flashing code but did go out. I checked when I got home and it was a P302. Misfire on cylinder #2. Hard to believe a bad plug wire or plug cold cause his type of surging. I was thinking about going after the TPS. that'* what it feels like. The car does not know where the TPS is at so it keeps fluctuating the fuel to cause the surging.

Noticed rear plug wires (2,4,6) kind of tight under harness and laying on valve cover. So unplugged and rerouted over top. During this I see #2 has either been chewed on by a mouse or rubbed through by valve cover. Got the black tape out and taped up really good along with other 2 and brace they are laying on. Drove all over today and did not hesitate or stumble at all. Cross my fingers but I think this did it.

Abbby, Please read the following journal entries as my car had some of the same issues as your SLE. I'm glad it was only your plug wire causing your surging (or other) issues.

1 March - Replaced Fuel Filter ($7)

1 March - Replaced Coil Packs ($60)

20 April - Replaced spark plugs ($16)

Car stalled at Stop sign andwould not restart. I had it towed to the local dealership for diagnosis.

- 23 April- Replaced Mass Airflow Sensor ($180)

Service Engine Light Illuminated

- Code 0302 (Misfire on Cylinder #2)

- Pulled #2 spark plug – discovered carbontracking (never heard of it or experienced it until this incident, I'm 52 yrsold)

- 29 June- Replaced all spark plugs ($35)

17 July - Replaced spark plug wires ($49)

- Replaced #2 spark plug wire after discoveringcarbon tracking in boot

Service Engine Light Illuminated

- Code 1361 (IgnitionControl Circuit Not Toggling After Enable Condition)
and 1362 (Ignition Control Module Bypass Circuit Low Input)

23 July - Replaced Ignition Control Module (ICM) (Delphi, $64.99)

Service Engine Light Illuminated

- Codes 1361 and 1362 reappeared
- On Scan Tool, it states crankshaft pulley “outof adjustment.” Because the crank pulley (harmonic balancer) on my 1999 cannotbe adjusted, the only other component it could be is the Crankshaft PositionSensor

31 July - Replaced Crankshaft Position Sensor ($54)

- Did not fix the problem

1 Aug - Took to dealership ($49.95, Diagnostic Check)

- Dealership states that I have a bad ICM

3 Aug - Tested ICM at Advanced Auto. I had it tested twice. Ittested “ok.” Installed back on car.

3 Aug - Removed and cleaned Idle Air Control (IAC) valve atthrottle body. It was pretty much covered

“from head to toe” in carbon. Focusingon the tip, I used regular carb cleaner and it did just fine.

- Test drove car. No issues with stalling orhigher, steady speed hesitation/fish biting and no Check Engine Light
- At Wide Open Throttle (WOT) there were smalldoses of hesitation, but I’m blaming other components, i.e., one or more injectorsnot at 100%, etc. At 16 years old and 195,000 miles, it could be any number ofthings. Ultimately though, keeping my fingers crossed, I think I resolved myCheck Engine Light issue (1361 and 1362 codes). For now I will deal with theslight hesitation at WOT.

13 Aug - Experiencing hesitation, jerking, and stalling, but noCheck Engine Light

- 13 Aug - Replaced Throttle Position Sensor (BWD, AdvancedAuto, $45.95)

Short lived remedy, startedhesitating, jerking, and stalling, again

- Removed throttle body and thoroughly cleanedcarbon from plate and inside of TB. Installed new gasket ($6)
- Be very careful removing and reinstalling thetamper-proof screws and torx head screws that secure the MAF sensor, IAC, andTPS, they tend to break very easily. I broke one of the six and opted topurchase a used throttle body ($25) instead of trying to drill out the brokenscrew. Unfortunately it needed to be cleaned just like my original did.

28 Aug – With everything that I’ve done over the past three months or so, theperformance and response is GREAT. Car didn’t run this good even when I firstbought it (with 58,000 miles)! I'm still experiencing intermittent mild surging,stalling while driving, and “fish biting” though. Next option is to replace theignition switch.

4 Sept – Replaced ignition switch (mileage 195,292) ($34, Delphi /eBay)

- Before I replaced the switch, I contacted mylocal Buick dealership to see if there were any ignition switch recalls for the1999 Buick Regal. Of course they said that there weren’t .
- I had NO issues with the Security lightilluminating on the IP when completed. I currently have 195,650 miles and allsystems are operating as intended. No more hesitation or stalling.

I would say you definitely found the issue, but I would install a new #2 wire at a minimum, and a full set of wires if you can afford it. That tape is a temporary solution at best.

It is really good tape

Spark plug wires carry 15,000 to 35,000 volts, which is why the insulation on a spark plug wire is thick and multi layered. You might have really good tape, but it probably won't withstand those voltages.

Leave the tape for now, but if the engine stumbling comes back change the wire.