Every now and then I get a bad start in my 2004 Acura TL. Happens about less than once a day. When I turn the key, the engine feels weak, studders and slowly increases RPM to around 800 RPM. Most of the time I start it up it jumps to 1.3k RPM and drops to steady idle RPM. I've changed the battery, replaced all 6 spark plugs but still can't fix the problem. Anyone have any thoughts on what it might be? Now, every time I start my car, I don't feel confident I'll get a nice strong start-up, I always worry that problem will come back.

 

If you look down at the starter, you can see two small screws in the back of the housing. Disconnect the battery and check for tightness. Theyground out the starter to the block. I'd check that. It's rarebut I jut replaced my brothers for that very reason on his 06 tl.
Causes excessive resistance

If you have a meter And an amp clamp, look it up at the neg cable to the battery. Close and lock all doors or latch them plus the hood. I don't know exactly draw spec for our car is,but on most newer bmws are between 40-80 milliamps.

Bring it to an indy shop like Firestone and ask if they can use their battery tester and check for cranking voltage and what's coming out of your alternator.

Just a few ideas.

 

It sure wouldn't be the battery or spark plugs. Does it only do it on cold starts? What happens if you let it idle for a while at 800 - does it eventually normalize? If the engine idles normally after a bit, it's probably not a problem at all.

 

Not only cold starts, it's usually the second start after I've been driving the car. If I let it idle at 800, it normalizes to a smooth idle again, it's just that beginning shudder that's worrying me