Running ruff when cold?

[KINGCOBRA86]

Alright every since I got it tuned with this new combo it runs like crap, when the car is stone cold, it has a real bad hesataion when I try to rev it ? And when I drive off it falls on its face, but once it gets to operating temp it runs a lot better but still falls on its face at 2k rpm

Also got codes
P2198
P2196

Tuner sent a new tune runs better when warmed up but the same when cold? Also the codes stop poping up
____________________________________

 

[wigginwilly00]

My jeep used to do that but it was the oxygen sensors. Good luck with it..

 

[fha8388]

I have that same problem.. op:

 

[04sleeper]

Sounds like either bad O2's or they did not tune STFT's correctly.

 

[KINGCOBRA86]

I did put new 02's on before the tune. Due to installing a new mid pipe , I'll try swapping my old ones in

 

[KINGCOBRA86]

Tuner sent updated file it runs a hole lot better but Still gummy when cold

 

[DSGWhippedSnake]

These cars hate cold startups. Mine has always hiccup'd when not fully warmed up. All I'll say is just really baby it until it gets to full operating temperature. It's going to sputter and cut out etc if you push it even the slightest bit while it's cold

 

[04sleeper]

Did your tuner do a sweep of RPM's and log each STFT at 1000, 1500, 2000, 2500, 3000, 3500 etc and make adjustments? If not your MAF Transfer Function could be off.

Also, depending on your exhaust set up, there may need some tweaking of the O2 sensor scalars as well.

Good luck.

 

[fha8388]

If the o2 sensor is faulty wouldnt it log a check engine light?

 

[KINGCOBRA86]

No code for o2's
Tuner said he made it go to open loop sooner

 

[scooby3694]

i am having the same problem. thanks for the answers above.

 

[KINGCOBRA86]

Hook up a wide band today

I'm seeing 12.5 - 13.1 cold idle

When I drive off and it falls on its face 20.1

Once it warms up and driving part throttle 15.5 - 16.1

At wot 12.1

 

[MICLO50]

o2's. are you running pump or E85?

 

[KINGCOBRA86]

Pump 91 octane

 

[KINGCOBRA86]

Put o2's in it still runs the same

 

[gmcconn1]

Assuming there is no mechanical issues (vacuum leaks)

Gas is MI is E10 - E15 so stoich is closer to 14.2. I am guessing your wide band reads lambda and does a conversion to come up with the AF based on a stoich point of 14.7. Based on that you look to be a bit lean even when warmed up at part throttle - I would look for as close to Lambda 1 (guessing 14.7 on your gage) - within 2-3 percent.

As far as 20:1 when cold - I have seen this a couple times when the injector data that was used in the tune is wrong. You can tune and get it close at one temperature - but there are errors baked in. As you get further away from the temperature the car was tuned in - the errors get more pronounced.

If you really want it right - I would recommend a good set of flow matched injectors you can get data for. If you look at some of the testing well equipped enthusiasts have done, flow rates can vary upwards of 8 % between injectors sold in a set - sometimes more. Good injectors with good data go a long way towards correcting these types of issues.

Again, this assumes the car is mechanically sound. A vacuum leak can do something similar to this. Smaller leak as the temperature goes up.

 

[KINGCOBRA86]

Car ran great with the port and stock injectors/maf

Day before the dyno tune i Installed the 80's and 2600 maf, it's been running like crap since

This winter ill send them out to get flow matched

 

[erod]

having this issue with my 03 cobra to, i just cleaned maf,iac,tps,checked tps voltage. new plugs, new o2's, now it starts adn revs to 3k and wont settle, wtf

 

[gmcconn1]

Are they Ford Racing 80 lb injectors?

 

[KINGCOBRA86]

Yes sir ford racing