The title sums up the symptoms
This has been happening for a couple of weeks now. When I come to a stop it idles funny and shakes. but it all seems fine when the heater is running.

yesterday the check engine light came on and got it checked and got code P0300. I've changed the IAC valve, spark plugs, coil pack and the rubber boots. a few months ago we got a new fuel pump and filter. when it first started shaking we took it to a shop and they checked the vacuum hoses and said that they were fine. I haven't checked cylinder pressure, but it's not spitting smoke out of the exhaust, so I'm hoping that's a good sign.

I'm not very good with cars and any help would be much appreciated.

EDIT: in addition to seeming fine when the heater is running, it only shakes when in gear. when it is in park or neutral it still idles funny but doesn't shake.

 

Welcome to the forum. What was the reason for the "new fuel pump and filter" and all the rest that you replaced? What do you mean by heater running? Depending on the air delivery mode, the A/C compressor may run when you turn on the blower. Is the A/C compressor running when it doesn't shake?

 

fuel pump went out, wife was driving home from work one night and it just died on her.

when I have the heat blowing, and I stop, the idle is stable and the car does not shake. mode doesn't seem to matter, defog, defog/feet, feet/upper body, as long as it's blowing it's calm. and the a/c isn't active. it's winter.

 

There must be some sort of voltage fluctuations, then. Check both ends of power and ground cables to and from the battery terminals.

 

if its a automatic u mite want to check see if its got a tork sensor on the tranny it may be that locking up the tork converter if u dont have any igintion problems

 

battery, alternator and connections check out fine.
as for the tork sensor... i have no idea. guess i will have to take it to a shop to have that checked.

cheers

 

Well, here's what I found for the P0300 code...

OBD-II Trouble Code: P0300 Random/Multiple Cylinder Misfire Detected

 

My gfs car has the same problem it shakes like crazy when its in drive but stopped at a light. I was thinking that it was a timing chain problem, (which it does have) but maybe it is the tork sensor too. Where is the tork sensor located? how do I test it? and where do I buy one?

 

That is a good link, just book marked that one.. Thanks

 

ignition mod i when though like 5 of them trust me on that lol