Lately, upon start up the engine isn't hitting on all cylinders. it shakes. When I give it a little gas,it smooths out and then runs fine. This happens intermittenly and not on cold start ups, so far just when the car is already warm ( like after returning from the resturant ) I had the TB cleaned 4 months ago. I have not yet changed out the tin terminals on the TB for the gold terminals, could this be the problem? Also, the spark plugs have never been changed ( only 20,000 miles on car ) Fuel pump was replaced 4 months ago, along with tensioners. Any thoughts? .....Note; I never give it any gas when I start it up. Just wondering if this could be the start of a problem? .....Thanks, mick Hey, has anyone done a video on changing the terminals on the TB position sensors?

 

It could be a million things we are going to need a little more info but here are some educated guesses:

_The shaking could be a misfire, and when the engine gets warm or you give it gas it goes away so it could be one or two ignition coils going out these go out all the time.

_The shaking could be a random misfire caused by your Air Mass meter.

If you pull some codes from the computer maybe I could pooint to you in the right direction

 

Probably a combination of air/vacuum leaks. Measure your fuel trims via any obd2 scanner live, that will show you immediately. The engine starts up with an intended fuel trim need, but if there are leaks in the system, O2 sensors see it at not enough fuel, short term trims can be all over the place immediately, computer starts throwing more fuel at engine making it stumble. it struggles with catching up to the short term values or until it air leak is matched by a better mixture, mainly more fuel n from the TB opening up, idling faster, but surpasses the leaking amount and a balance is achieved - somewhat. If you check your long term full trim numbers vs short, you'll probably find a difference between them being pretty high, longs of over 10% is bad, short term rising over 5% is also indicative of air/vac leaks. Theres many possibe contributing sources, including PCV and EGR lines, even oil cap and dipstick oring seals. Good trims are ~3-4% short, 6-7% long.

 

Had Advance Auto read my codes, just the standard p1111. I dont have a obd2 scanner, but may be a good investment. The problem did not occur on three start-ups today, but I'll keep alert to it. Thanks, Mick