Hey all,

A few weeks ago my started having a rough idle at start up when cold or warm. If I give it gas so that the idle reaches 3000rpm the car runs fine. It doesn't hesitate when I come to a stop. 96 toyota camry Le 2.2Engine 4cyl. Has 258,000miles.

I recently replace the following:

Motor mounts
Timing belt
Thermostat
Radiator and fluid
Spark plugs {had a misfire)
Air filter
Battery & cables

Hopefully someone has experienced something similar and has suggestions.

Thank you in advance.

 

Here's my default approach to these kind of things. Try to find if there's a single cylinder at fault; if so, you can then see
if it's a spark plug symptom issue. These are cheap to fix. @ 260,000 miles you're not going to spend a bunch on it...

Prop open the hood when next cold start and idling rough, then pull off the spark plug wires one at a time, replace it,
then pull the next one - to identify which cylinder's pulled wire doesn't cause the engine to die or stumble worse.

This cylinder, that doesn't affect the idle speed, is the one causing the problem. It's not firing on start-up.
So focus on fixing this one.




Speculation here: a possible temporary spark plug fix, and temp fixes may last tens of thousands of miles if it's right one, is to see
if the spark plug is 'fouled.' So unscrew/remove it and look at it. If fouled (black or oily look) take it to auto parts store and
buy same plug in temp range 2 grades hotter; this will resist fouling. Like about $3.