Runs extremely rich on cold starts

[brandnew161]

Ok here is the deal. my tsi runs rich when it is started up while cold. By rich I mean over 10AFR. So rich that my AEM UEGO doesnt even read that low. So rich that after sitting in the car for 30 seconds I smell like I worked a 9 hour shift at a gas station. It sucks. Heres the thing though, As soon as the car gets to operationg temp (coolant needle in middle of gauge) the car runs and idles great. When it is cold, the car barely idles and sputters if i give it gas.

To get around this I have to use my safcII and take my "lo 800" from 25% all the way down to -20%. Then, when the car warms up I bring the "lo 800" back up to 25%.

Here is what I have done:
I removed all emissions solenoids.
No loose vacuum lines
Aeromotive afpr is set correctly
No leaky injectors since it runs fine after it warms up


I am using a safcII, GM MAF, MAFT V1.3. 680cc injectors

The car in general is tuned great. I can hit full boost @ 15 psi and my AFR will be 11. However, cold idle is what hurtin.

Any suggestions? Only thing I can think of remaining is the coolant temp sensor..

I am considering buying the upgraded 2.02 MAFT chip if I cant figure anything out. Oh and I should add that this problem started when I installed my maf, maft, and injectors all in the same night. At first i thought it was poor tuning but as of now I believe it is something else

Thanks for the help

 

[Spoolin18]

Ok here is the deal. my tsi runs rich when it is started up while cold. By rich I mean over 10AFR. So rich that my AEM UEGO doesnt even read that low. So rich that after sitting in the car for 30 seconds I smell like I worked a 9 hour shift at a gas station. It sucks. Heres the thing though, As soon as the car gets to operationg temp (coolant needle in middle of gauge) the car runs and idles great. When it is cold, the car barely idles and sputters if i give it gas.

To get around this I have to use my safcII and take my "lo 800" from 25% all the way down to -20%. Then, when the car warms up I bring the "lo 800" back up to 25%.

Here is what I have done:
I removed all emissions solenoids.
No loose vacuum lines
Aeromotive afpr is set correctly
No leaky injectors since it runs fine after it warms up


I am using a safcII, GM MAF, MAFT V1.3. 680cc injectors

The car in general is tuned great. I can hit full boost @ 15 psi and my AFR will be 11. However, cold idle is what hurtin.

Any suggestions? Only thing I can think of remaining is the coolant temp sensor..

I am considering buying the upgraded 2.02 MAFT chip if I cant figure anything out. Oh and I should add that this problem started when I installed my maf, maft, and injectors all in the same night. At first i thought it was poor tuning but as of now I believe it is something else

Thanks for the help

Mafts are very hard to use, have you messed with any of the settings on the maft?

 

[1gcrazy]

Coolant Temp Sensor. Check the wire....

 

[zhjiln]

how are your fuel trims? if its off, its adding fuel to compensate ?? i dont know..

 

[Rob10_99]

CTS yep, I bet its unplugged or corroded/broken.

 

[slow4g6392tsi]

I heard once that on most vehicles, the ECU does not go by the O2 sensors readings when cold because the O2 sensor has to warm up to read correctly or something. So it goes by memory of how much fuel it would usually use in that situation until the O2 sensor is warm. I could see your problem relating to that. I just wish I could remember where I heard that and if it was specific to a certain vehicle.

 

[Spoolin18]

I heard once that on most vehicles, the ECU does not go by the O2 sensors readings when cold because the O2 sensor has to warm up to read correctly or something. So it goes by memory of how much fuel it would usually use in that situation until the O2 sensor is warm. I could see your problem relating to that. I just wish I could remember where I heard that and if it was specific to a certain vehicle.

I'm not sure that works with a wideband 02??? probably cts or fuel trim related from his maft, especially if he installed a used maft that had not been reset.

 

[Rob10_99]

Yes the 02 goes through a warm up cycle, couldn't tell you exactly how long it is for each different manufacturer out there.

 

[slow4g6392tsi]

I'm not sure that works with a wideband 02??? probably cts or fuel trim related from his maft, especially if he installed a used maft that had not been reset.

What's a WBO2 have to do with this? I was thinking maybe it was going off memory while the O2 sensor warmed up and maybe the memory was from the old injectors so it was ignoring the actual values & compensation, then keeping them open as long as it would have with 450s.

 

[fstfcs]

I have this same issue.......and im stock except for an intercooler and BOV...

 

[Spoolin18]

What's a WBO2 have to do with this? I was thinking maybe it was going off memory while the O2 sensor warmed up and maybe the memory was from the old injectors so it was ignoring the actual values & compensation, then keeping them open as long as it would have with 450s.

I get you, never mind.

 

[brandnew161]

wow thanks for the replies.

As far as the dip switches on my maft, they are all off (3"maf, prevent fuel cut, aux fuel control)
my base:7 -35% for 700 cc injectors (i have 680cc)
idle: 0 0% (on safc when warm it is 25%, when cold i change it to -30%)
mid: c -20%
wot: 9 -35%
aux: 0 (not used)
*remember its v1.3

By checking the wire on the CTS, what do you mean? The contact is good i think. I used sandpaper to get rid of any rust etc

What do you mean by resetting the maft? When i bought it used I just made sure all the presets were at zero before tuning. Ive reset the ecu...but not the maft, idk how. Is it possible to do?

and i'm sure that if it were my 02 sensor I would most likely have a code for it and i would have more problems than just a poor cold idle

 

[nathanticket]

ya i have ran into similar issues with the 2.2 version MAF-T. Im also tuning with the AFC Neo which is imo garbage. First reset the MAF-T. I believe you can reset it by unhooking the battery for awhile and re-hook it up. Usually that would solve things for me when it came to using it. I had the opposite problem tho. on cold starts it would run lean until warmed up even with the extra fuel added by the dip switch setting. Might want to try setting your SAFC back to 0 trim and then reset the MAFT and get your cold start tune with the dip switches. Then make your smaller corrections with your SAFC.

-nate

 

[brandnew161]

alrighty sounds like a plan. Ill give it a shot. Thanks

 

[johnovision27]

What kind of oil is in there at the moment? I run 20W50 in the summer and waited a little too long to switch it out when the temp started dropping and had the same issue.
Switch the oil and the problem solved itself.

Then again, I don't have 1/2 the tuning electronics that you have, but it's just a thought.

 

[95gst16g]

What kind of oil is in there at the moment? I run 20W50 in the summer and waited a little too long to switch it out when the temp started dropping and had the same issue.
Switch the oil and the problem solved itself.

Then again, I don't have 1/2 the tuning electronics that you have, but it's just a thought.

Not really sure how changing different oil weights would fix this problem?Maybe you just got lucky and the car fixed itself somehow and you just happened to change the oil around the same time.

 

[sketzshane]

If you were using ECU tuning then you could adjust and do injector compensation for those said 680cc injectors etc... The tool that are used for tuning can play a vital part in getting a car to run right. I always believe that people should some time concentrate more on the end result than present and of such maybe you would have opted to probably buy a better tool for tuning maybe Greddy Emanage Ultimate, AEM ECU, DSM Link etc... Running 2 piggybacks(SAFC2 and MAF Translator) can always lead to additional issues and the tuner has to be fully knowledgeable on exactly how that specified car/model operates on how to set the paramters.

 

[brandnew161]

^not everyone has all that money for said tuning devices. I would definately opt for those, but they are not an option for a full time college kid workin a low paying job. Maybe later.

Anyways the problem is fixed. Turned out that the the gasket between the turbo and the manifold was half burnt up. Also, the gasket between the o2 housing and turbo was toast, and the 4 mani to turbo bolts were loose. Apparently it must have been very poor o2 readings due to all of the leaks. Installed a new tubular mani and new gaskets, reset ecu and runs great

Thanks for the help guys

 

[95gst16g]

^not everyone has all that money for said tuning devices. I would definately opt for those, but they are not an option for a full time college kid workin a low paying job. Maybe later.

Anyways the problem is fixed. Turned out that the the gasket between the turbo and the manifold was half burnt up. Also, the gasket between the o2 housing and turbo was toast, and the 4 mani to turbo bolts were loose. Apparently it must have been very poor o2 readings due to all of the leaks. Installed a new tubular mani and new gaskets, reset ecu and runs great

Thanks for the help guys

You cant afford Dsmlink but yet you just got a new tubular manifold haha j/k I am poor as hell but I managed to take last years tax return check and buy me Ecmlink v3 and some 1000cc injectors.I am very glad I did it.Good luck with your car.

 

[brandnew161]

Thanks. I bought a ebay tubular not anything fancy. My cast mani was cracked in a few places so i just needed a quick replacement. The turbo/exhaust is held up on it own by a support bracket so there is not much weight on the manifold if any. Hopefully it will last a while.

 

[95gst16g]

I know the tubular manifolds look dope but I would have just bought a evo or fp cast manifold.Or just save up more cash and buy a brand name manifold that is proven.I know the cash situation sucks but you might be buying another manifold sooner then you think.Then by the time you buy a new one plus the money you spent on the ebay one that would be pretty close to buying a good tubular mani.....Buy good and buy once.Buy Ebay most likely buy twice.Hope you have good luck with the manifold.

 

[brandnew161]

haha thanks for the tips but i'm aware. I didnt want a cast mani nor do i want to spend $700 on a real one. I didnt want to spend a whole lot of cash now because I'm not going to have the e3 16g for much longer. I'm going to go bigger and am going to need a mani with a external wastegate. Wasnt really planning on it but since I bought 272/272 and gears i might as well. I had a 33 cast manifold on the car already but it was cracked in a few places and didnt want to mess with one again, plus it was never fun drilling out snapped high grade manifold bolts. What a joy

 

[nathanticket]

glad to hear you got it fixed!

 

[Kevinw627]

How were you able to solve your running rich prob, because my car is stock and it has always ran fine. Right after installing a FMIC, Hardpiping/BOV, Exhaust, its runing insanely rich?I Need help???