difficulty accelerating after cold start

[chvyeter]

Whenever I first start the car it doesn't want t accelerate smoothly. It bucks and jumps a little until it's warm. Any ideas? It's a totally stock 14 GT

 

[king_13]

Do you let the RPMS drop from ~1400 to ~900?


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[chvyeter]

Do you let the RPMS drop from ~1400 to ~900?


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I sometimes wait for maybe a few seconds but probably doesn't idle down. I don't pay attention.

 

[skwerl]

You may have a vacuum or intake leak somewhere. The factory tune is typically very good on cold operation (too good, sometimes). I grew up in an era of carburetors so I'm used to letting an engine warm up for a minute or two before expecting perfect reactions from my inputs but kids today only know and expect perfect performance from the very first engine rotation.

Without more info it's hard to say if there's actually a problem or if you're just expecting too much too soon.

 

[king_13]

I sometimes wait for maybe a few seconds but probably doesn't idle down. I don't pay attention.

Give it a 30 seconds and see if that fixes it.


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[Speedboosted]

Let the idle drop down to it's normal state, then drive. The O2's and drive by wire do funky things when the car is first started.

 

[chvyeter]

Yeah I'm thinking it's just a weird thing these do. It just turned 15k miles.

 

[frank s]

The '13 I had did something like that for a few weeks, then got over it all on its own.

 

[dans08gt]

My 2012 F-150 did it just about every day. was told to clean throttle body. cleaned mine and it has reduced it a lot.

 

[noldevin]

Mine has always done that. The 3.73s don't help any. Just have to use a little more clutch when the car is cold. It does help if you give it a chance for the idle to come down, but still common in the first 5 minutes or so of running.

 

[redfirepearlgt]

Got a video with audio? Most younger guys have the ability to do this. Try making one and uploading. AS stated it may be a lack of patience. My 14 takes a minute or two for throttle response and so forth to act normal. That is simply part of the PCM and of course the wide band O2's needing warm up time before they come on line. At start up (cold) remember that you have a period of time in which the car is running open loop before the O2 sensors reach proper operating temp. When that happens the PCM then begins monitoring them as a tuner explained it to me which makes perfect common sense. My 05 could be that way on cooler mornings if I took off too soon before letting things warm up, especially after not driving it all week. Then it would be fine after that.

 

[Boaisy]

Check for vacuum leaks, make sure everything between the MAF and intake is on properly ("unmetered air" can cause issues), and let the car warm up before moving. It only takes a few seconds for it to start idling down unless it is freezing weather.

 

[Sky Render]

Got a video with audio? Most younger guys have the ability to do this. Try making one and uploading. AS stated it may be a lack of patience. My 14 takes a minute or two for throttle response and so forth to act normal. That is simply part of the PCM and of course the wide band O2's needing warm up time before they come on line. At start up (cold) remember that you have a period of time in which the car is running open loop before the O2 sensors reach proper operating temp. When that happens the PCM then begins monitoring them as a tuner explained it to me which makes perfect common sense. My 05 could be that way on cooler mornings if I took off too soon before letting things warm up, especially after not driving it all week. Then it would be fine after that.

It takes only a couple seconds for the car to go into closed loop. The O2 sensors have heaters to bring them up to temperature faster.

 

[redfirepearlgt]

It takes only a couple seconds for the car to go into closed loop. The O2 sensors have heaters to bring them up to temperature faster.

hmmmm...guess I got bad 411 from a tuner. I was given the impression it took 30-60 seconds (which can seem like minutes ha-ha!). Thanks for the correction.

 

[Sky Render]

hmmmm...guess I got bad 411 from a tuner. I was given the impression it took 30-60 seconds (which can seem like minutes ha-ha!). Thanks for the correction.

Plug in a scan gauge and start the car. It's not even 5 seconds before the widebands show a reading.

 

[redfirepearlgt]

Plug in a scan gauge and start the car. It's not even 5 seconds before the widebands show a reading.

Will do that at next data log session. Just received some parts and awaiting the tune revision for them which will require datalogging. I want to check that out as well as another point my tuner doesn't ask for that I recently learned about in another thread. Thanks.

It's a whole new world with cars compared to the old days of carbs, points, and distributors. Makes me glad I'm no older or younger than I am. I have had the opportunity to experience a little of both worlds. I'll take this one. LOL!

 

[5lho]

My previous stick 3.73 car would do this on cold holes, with the stock tune. Procal fixed a lot of that. My current auto car does almost none of this, straight out of the driveway, on the stock tune. I went aftermarket on the tune as well but the stock tune was miles better than the previous car's stock tune.

This sucker, as are almost all modern cars, is in closed loop right away.

 

[travelers]

After installing the ARHs on my '07 car we had to up the time on the O2 heaters to keep it from getting a CEL. I know that's a 3V computer but I'm not sure if it's needed on an coyote. I know my '11 has ARHs with a Lund tune and have no problems