Hi,
I'm not sure how to diagnose this problem with my 99 4runner V6. When I start the car, the whole car putters and shakes for about 30 secs, then my rpms automatically jump up to around 1500-1800 and then it starts to feel smoother. But not completely smooth. When driving there is still the feeling of the car puttering, but it's most noticeable in idle. Also there feels to be a loss in power. Just yesterday it died on me while stopped.

I looked around the forum and was told to check the spark plugs and coils, which I did. Also, I replaced those about a year ago. Could it be a bad alternator? Does anyone have any ideas? Thanks in advance.

 

Any smoke when you first start it and it's sputtering for 30 seconds? If not it sounds like you need to clean your throttle body and IAC.

 

I haven't noticed any smoke coming from under the hood. I'll clean those and update. Thanks kball.

 

No smoke under the hood is great but I meant excess from the exhaust. Like as in white smoke with a sweet musty smell.

 

That's almost what mine's doing 2.7L...I am going to change the fuel pressure regulator soon as everything else besides fuel injectors have been changed...

 

You may have a dead cylinder or a massive air leak. Was any work done recently? How old are the spark plugs? any codes? CEL light on?

 

Stuck/dirty IAC valve?

Or, a leaky HG that is dropping coolant into the cylinder as it cools off and then it runs wonky until the coolant clears the cylinder. Are you using any coolant?

 

Oh I see. I'll start it up and check it out.

Nothing recent. It started about 1 week ago. The spark plugs, coils, and a fuel injector were changed about a year ago. I do have a p0420 code and another p0420 code pending.

I'm planning to clean the TB and IAC today. I am and I haven't noticed any overheating issues either.

 

So no coolant loss?

 

Sorry it's been so long since a reply. I've been out of town.

I was checking the coolant, when I noticed a large tear in the rubber vacuum hose that connects to the throttle body. The connections seemed loose too. I replaced the hose and tightened up everything and it seems to be running fine now. Uggh really stupid of me for missing something so obvious. Thanks for all the help everyone!