Cold start ups

[Fast05]

Ok, I have had a problem with my stang for a while now. If I start the car up cold and start driving right away, the engine starts to act like its going to putter and die and starts to make the car buck. Almost as if the throttle was opening and closing though I'm not moving the gas pedal up and down...
So I push the clutch in and let the car coast, go into second and it does it again. I roll the car to a stop, put it in first and go again but this time no problems, although this even always seems to trigger the check engline light. When I run diagnostics I always get a code that reads O2 Sensor Bank 1, Sensor 2 stuck lean. Today though, when this happened, I ran the diagnostics again and I got 3 codes:
O2 Sensor Bank 1, Sensor 1 stuck lean
O2 Sensor Bank 1, Sensor 2 stuck rich
Systems readiness test not complete
I don't remember the exact code for that 3rd one....but it's close
I probably need to get the car custom tuned on a dyno, but have had no luck finding one in my area, if anyone knows where to search for one ? I live in Corpus Christi, TX and am willing to drive if necessary. I still think that with my canned tune the car is running lean so maybe this is the cause? Any ideas?
Thanks in advance for any help or advice

 

[PanhandleGT]

I have the exact same problem. I also have the JBA's but with steeda CAI and 93 tune, although my check engine light never comes on. I have noticed a substanial loss in performance the last couple of weeks and decided to pull her to a shop in nearby atlanta (8 hours). Im fed up...no one here has a clue. My best guess is that when I installed the L/T's there were four O2 holes with only 2 O2 sensors. Since they reached the holes toward the tail end of the exhaust I put them in and pluged the fronts. I have been told to buy extensions and do the opposite. Good luck.

 

[klee024]

I have been having the same issue, but my car is completely stock. It bucks when you try to start driving if you don't wait a few seconds. If I wait for 15-20 seconds it is completely fine, but I am not exactly thrilled about it.

 

[TAP4636]

You probably shouldn't drive it completely cold anyway. During the winter months, you should let it sit idle for a bit before driving.

 

[klee024]

Yeah...That was my thought, and why I wasn't tremendously worried about it.

 

[Fast05]

You probably shouldn't drive it completely cold anyway. During the winter months, you should let it sit idle for a bit before driving.

Yea, I forgot to mention that if I let the car idle for aboue 2-3 minutes and warm up she gives me no problems...it just seems weird though that I can't get in the car and go if I'm in a hurry. It's not that big a deal but I've never had a car with a problem like this

 

[LarryS]

Yea, I forgot to mention that if I let the car idle for aboue 2-3 minutes and warm up she gives me no problems...it just seems weird though that I can't get in the car and go if I'm in a hurry. It's not that big a deal but I've never had a car with a problem like this

My engine on my 06 GT idles way too fast for a minute or so. That can be fixed with tuning. I would be willing to bet your problem could be fixed with tuning with a tuner that has full access to the PCM, ECT or what ever our computer is called.

My 98 Camaro's cold idle was terrible stock until I got HP Tuner. I tuned it myself and now it's perfect even with the addition of a big cam.

 

[JTGrant]

Ok, I have had a problem with my stang for a while now. If I start the car up cold and start driving right away, the engine starts to act like its going to putter and die and starts to make the car buck. Almost as if the throttle was opening and closing though I'm not moving the gas pedal up and down...
So I push the clutch in and let the car coast, go into second and it does it again. I roll the car to a stop, put it in first and go again but this time no problems, although this even always seems to trigger the check engline light. When I run diagnostics I always get a code that reads O2 Sensor Bank 1, Sensor 2 stuck lean. Today though, when this happened, I ran the diagnostics again and I got 3 codes:
O2 Sensor Bank 1, Sensor 1 stuck lean
O2 Sensor Bank 1, Sensor 2 stuck rich
Systems readiness test not complete
I don't remember the exact code for that 3rd one....but it's close
I probably need to get the car custom tuned on a dyno, but have had no luck finding one in my area, if anyone knows where to search for one ? I live in Corpus Christi, TX and am willing to drive if necessary. I still think that with my canned tune the car is running lean so maybe this is the cause? Any ideas?
Thanks in advance for any help or advice

this is the same problem that I am having

 

[JTGrant]

any updates?

 

[Fast05]

Unfortunately still dealing with this problem. I am ready to slap my stock exhaust back on and forget about it

 

[anthony05gt]

Take it back to the guy who supplied the tune. Sounds like he needs to richen up the fast idle settings for cold starts. It's an easy fix.

 

[official_style]

i got the same problem. the problem is, that your o2 sensors are not getting warm quick enough, and its running poorly till they heat up. i have american racing longtubes. everyone who has LTs is having this problem. i think the solution is to have the tuner set it so that the o2s dont turn on for a longer period of time. im going to mustang magic to find out about this. and yes mine throws a code when this happens, if i drive. if i dont it wont throw the code. get some MIL elims or turn off your rear o2 sensors. as for the guy who only said he installed 2 o2 sensors and plugged 2 holes? what are u talking about these cars have 4 o2s stock!

 

[JTGrant]

all people with this problem need to keep this thread alive. we need to find a fix.

 

[Fast05]

all people with this problem need to keep this thread alive. we need to find a fix.

I am going back to my tuner next Saturday (16th) and going to have them look at the tune again. He keeps telling me that my 02 sensor must be faulty and that's why it keeps triggering my CEL but when I had my bamachips tune I never had this problem. Only problem I had with the bamachips tune was the rough cold start up and ocasional ping which wasn't good.

Anyway, with my current tune I'm still getting rough cold start up but not near as bad as I was before. I had taken it back to the tuner about a month ago and they adjusted the time needed for the 02 sensors to warm up so I'm guessing it just needs to be extended a little bit longer. As far as the CEL light coming on, it only does that if I cruise with the RPMs below 2500 so I know it's not the 02 sensor. If I get the problem fixed I will have him email me the tune.

:SNSign:

 

[JTGrant]

let us know what happens.

 

[official_style]

i went to my tuner today, and they havent found a fix yet. the problem is the o2s are just not getting warm fast enough. your tuner was able to make your car run in the warm up mode for longer, before turning the o2s on? i thought this wasnt possible? as of now im just letting it warm up. and i get the same code, bank 1 sensor 1, i already changed it, so its not the sensor. only happens if its cold. someones gonna figure this out eventually.

 

[Jenns01TA]

So should I chime in here? I am not sure how much these tuners are compensating for the degree of control the the o2 sensors have in the grand scheme of things. The VVTS + Heated O2 circuit calculation and alogrithm that needs to compensate for the increase in AF, etc. etc. To properly tune for all the variables takes a computer science specialist with a mechanical flare and a strong EEC/PCM understanding.

I am but a young lady who has a deep fixation and love for the Stang. Specifically, the amount of pure data "logic" and mathmatical alogrithms necessary to make these things perform properly and optimally.

I gave up my tools and traded them in for a computer. This stuff is amazing, although, I miss the simplicity of pre-OBD/FI engines.

Instead of boring you guys with the fundamentals, I am going to link this handy little "arm chair mechanics" guide to 02 Sensor diagnostics. Please do not flog me for hyperlinking this.

http://www.aa1car.com/library/o2sensor.htm

When you get to the middle portion of the dry tech talk you will find an answer to your proverbial question "WTF?"....

We love to modify these Stangs. Given. But, these modulated vehicles have more computer modules than the space shuttle and leave more room for error.

I hope this helps. I do not have the answer on how to "code" the correction to the Voltage and Loop calculations required for each of your modifications, but this should at least point you in the right direction.

Good Luck Fellas. This is one reason that I have kept my Daily Driver S197 Stock. This EEC/PCM with OBD-II, VVT and DBW is a little too much for this gal.

 

[iskwezm]

So should I chime in here? I am not sure how much these tuners are compensating for the degree of control the the o2 sensors have in the grand scheme of things. The VVTS + Heated O2 circuit calculation and alogrithm that needs to compensate for the increase in AF, etc. etc. To properly tune for all the variables takes a computer science specialist with a mechanical flare and a strong EEC/PCM understanding.

I am but a young lady who has a deep fixation and love for the Stang. Specifically, the amount of pure data "logic" and mathmatical alogrithms necessary to make these things perform properly and optimally.

I gave up my tools and traded them in for a computer. This stuff is amazing, although, I miss the simplicity of pre-OBD/FI engines.

Instead of boring you guys with the fundamentals, I am going to link this handy little "arm chair mechanics" guide to 02 Sensor diagnostics. Please do not flog me for hyperlinking this.

http://www.aa1car.com/library/o2sensor.htm

When you get to the middle portion of the dry tech talk you will find an answer to your proverbial question "WTF?"....

We love to modify these Stangs. Given. But, these modulated vehicles have more computer modules than the space shuttle and leave more room for error.

I hope this helps. I do not have the answer on how to "code" the correction to the Voltage and Loop calculations required for each of your modifications, but this should at least point you in the right direction.

Good Luck Fellas. This is one reason that I have kept my Daily Driver S197 Stock. This EEC/PCM with OBD-II, VVT and DBW is a little too much for this gal.

wow, talk dirt again

 

[official_style]

that was actually pretty interesting! now i know what these stupid things actually do lol. it seems to me from reading this that setting the car to stay in open loop would solve the LT cold start problem. am i right?

 

[Jenns01TA]

that was actually pretty interesting! now i know what these stupid things actually do lol. it seems to me from reading this that setting the car to stay in open loop would solve the LT cold start problem. am i right?

Final Answer? You have just answered your proverbial question of 'WTF" ? You now have your marching orders, Captain.

Caution should be exercised when considering locking an open loop signal with the PCM/EEC-V/OBD-II. Since no signal is received from the O2 sensor, as is the case with the cold engine start sensor bank DC throw, the computer will order that fixed/unchanging rich fuel mixture. This in itself will cause additional EEC/PCM issues that will have profound and punishing ramifications on the llife of the engine.

Since there are no WRAF sensors available that I am aware of for Ford, what in fact needs to be done is a change in the control voltage level sent from the PCM to the O2 sensors. There needs to be compensation for the deviation from the stock AF ratio that the PCM is calculating.

I am NOT your gal. You will need to find someone who is capable of calculating the deviation to balance out the AF deviation to voltage minimum/maximum on the heated 02s.

It is interesting huh? Most of us have just scratched the surface of the technical knowledge needed to keep these beasts running at optimal levels, especially after exhaust and intake modifications.

"I LIVE FOR THIS....". -Vin Diseal -