ECMlink Can't Resolve Cold Starts Been About A Year No Success Logs Attached

[bo0st]

I've been trying to resolve my cold start problems on my 95 GST for about a year now with no success.

After 5 minutes of warming up, the car no longer dies and finally begins to idle properly. Good enough to drive it.

I've uploaded a new log from today, after I changed my front 02 Sensor, which everyone was claiming to be the problem. I didn't see how a front 02 sensor could be the problem (cold starts) but I spent the $85 anyway on the sensor alone to change it today.

I uploaded the .elg log to SendSpace here

914 seconds changed front 02 sensor.elg

As it's slightly over the size limit for forum attachments.

I'm offering a $100 Paypal reward to anyone who helps me successfully resolve this cold start problem. I want to be able to get into my GST and turn the key and it starts up. I know I'm not too far away from that.

My 420a has been more reliable than my GST, that just isn't right.

Help me out guys.

 

[1G Eclipse94928]

what have you tried so far?
Boost leak test?
Upgrade list up to date?
Exhaust leak?

 

[white92talontsi]

I've been trying to resolve my cold start problems on my 95 GST for about a year now with no success.

After 5 minutes of warming up, the car no longer dies and finally begins to idle properly. Good enough to drive it.

I've uploaded a new log from today, after I changed my front 02 Sensor, which everyone was claiming to be the problem. I didn't see how a front 02 sensor could be the problem (cold starts) but I spent the $85 anyway on the sensor alone to change it today.

I uploaded the .elg log to SendSpace here

914 seconds changed front 02 sensor.elg

As it's slightly over the size limit for forum attachments.

I'm offering a $100 Paypal reward to anyone who helps me successfully resolve this cold start problem. I want to be able to get into my GST and turn the key and it starts up. I know I'm not too far away from that.

My 420a has been more reliable than my GST, that just isn't right.

Help me out guys.

I see a couple of things. Your car is not going into closed loop to allow the ECU to control fuel trims.

Can you capture another log and this time make sure you are logging CombinedFT and ISCposition.

Also, Log MAFRaw as well.

You also need to go into your DTC's tab and recheck
Cylinder misfire
Fuel trim
Closed loop
Those always need to stay checked on.

From what I am seeing in the Log is all criteria is met for the car to run in closed loop mode but the front o2 "appears" dead. This can mean a few things

The number one reason the front o2 could "appear" dead is due to fuel trims being too far off, the ECU will never go in closed loop.

There could be a mechanical issue with the car as well. You may have mechanical timing off, This needs to be checked.

Does the engine run smooth? Is it misfiring?

Do the steps I listed above and send a new log please.

 

[snowborder714]

Make sure you read these and follow all suggestions/steps before posting another log, just so we're on the same baseline.
http://www.dsmtuners.com/forums/ecm...efore-you-ask-ecmlink-dsmlink-log-advice.html
http://www.dsmtuners.com/forums/ecmlink-tuning-log-file-advice/444831-list-values-log.html


Is it truly a stock car with just a BOV and air filter? I see you have the "Use non-95/96 style cam angle sensor" box checked, which shouldn't be if the car is fully stock.

The front o2 won't have specific issues in regards to cold starts, but it does affect all idle and driving as the ECU has nothing to gauge the fuel trims off of (as noted above about the car not going into closed loop).
http://www.dsmlink.com/wiki/fueltrimupdatepoints

 

[white92talontsi]

Good call Snowboarder714. I saw that was checked but failed to look at what year his car is.


To the OP, if you have a 95/96 That box does not need to be checked. When you checked that box did you also swap the plug wires? If you did then uncheck the box and swap the plug wires back to there Factory configured order.

 

[okm12346]

The engine has problems when its cold and its still in open loop. After it warms up the o2 sensor takes over the fuel trims and the engine doesnt need extra air to operate. I say extra air as extra air bypasses the throttle plate thru the FIAV to allow the engine to work at 1500 rpm (cold start). As the engine warms up, the FIAV closes and then the IAC(ISC) takes control of idle RPMs.

Lets say the throttle body has a block off plate. In order to start the engine in the morning, the pedal needs to be pressed to provide the extra air for the engine to start. I say this because your engine seems to lack this extra air that is bypassed thru the FIAV. In two words, you have a bad FIAV.

The FIAV is in the bottom part of the throttle body. Coolant runs thru the FIAV, thats how it knows when the car is cold or warm. So first things to check is if the coolant lines are still connected or restricted.

Second, since the FIAV is part of the throttle body and the TB is bolted to the intake manifold where oil from the valve cover comes in thru the PCV valve and exhaust gases also find their way in thr the EGR valve, all that oil and carbon can build up in the throttle body and FIAV causing it to fail in bypassing the extra air the engine needs to have to operate during cold starts

Take the TB apart and clean it out. If cleaning out doesnt help then you'll need a new bottom part of TB.

 

[bo0st]

what have you tried so far?
Boost leak test?
Upgrade list up to date?
Exhaust leak?

BLT performed no known boost leaks or exhaust leaks. Upgrade list is up to date. Just a K&N and a greedy BOV and a 1g CAS. That's why 1G CAS is checked in ECMLink.

I see a couple of things. Your car is not going into closed loop to allow the ECU to control fuel trims.

Can you capture another log and this time make sure you are logging CombinedFT and ISCposition.

Also, Log MAFRaw as well.

You also need to go into your DTC's tab and recheck
Cylinder misfire
Fuel trim
Closed loop
Those always need to stay checked on.

From what I am seeing in the Log is all criteria is met for the car to run in closed loop mode but the front o2 "appears" dead. This can mean a few things

The number one reason the front o2 could "appear" dead is due to fuel trims being too far off, the ECU will never go in closed loop.

There could be a mechanical issue with the car as well. You may have mechanical timing off, This needs to be checked.

Does the engine run smooth? Is it misfiring?

Do the steps I listed above and send a new log please.

I will do another log ASAP and log everything you mentioned.

This time it will be with a new front 02 Sensor.

The engine does in fact run smooth after it's warmed up and no isn't misfiring at all.

Make sure you read these and follow all suggestions/steps before posting another log, just so we're on the same baseline.
http://www.dsmtuners.com/forums/ecm...efore-you-ask-ecmlink-dsmlink-log-advice.html
http://www.dsmtuners.com/forums/ecmlink-tuning-log-file-advice/444831-list-values-log.html


Is it truly a stock car with just a BOV and air filter? I see you have the "Use non-95/96 style cam angle sensor" box checked, which shouldn't be if the car is fully stock.

The front o2 won't have specific issues in regards to cold starts, but it does affect all idle and driving as the ECU has nothing to gauge the fuel trims off of (as noted above about the car not going into closed loop).
fueltrimupdatepoints [ECMTuning - wiki]

Yes it is truly a stock car besides the filter, BOV & a 1G CAS.

Good call Snowboarder714. I saw that was checked but failed to look at what year his car is.


To the OP, if you have a 95/96 That box does not need to be checked. When you checked that box did you also swap the plug wires? If you did then uncheck the box and swap the plug wires back to there Factory configured order.

Yes I checked that because I have a 95 GST with a 1G CAS. The wires have been swapped according to ECMLinks recommendations.

The engine has problems when its cold and its still in open loop. After it warms up the o2 sensor takes over the fuel trims and the engine doesnt need extra air to operate. I say extra air as extra air bypasses the throttle plate thru the FIAV to allow the engine to work at 1500 rpm (cold start). As the engine warms up, the FIAV closes and then the IAC(ISC) takes control of idle RPMs.

Lets say the throttle body has a block off plate. In order to start the engine in the morning, the pedal needs to be pressed to provide the extra air for the engine to start. I say this because your engine seems to lack this extra air that is bypassed thru the FIAV. In two words, you have a bad FIAV.

The FIAV is in the bottom part of the throttle body. Coolant runs thru the FIAV, thats how it knows when the car is cold or warm. So first things to check is if the coolant lines are still connected or restricted.

Second, since the FIAV is part of the throttle body and the TB is bolted to the intake manifold where oil from the valve cover comes in thru the PCV valve and exhaust gases also find their way in thr the EGR valve, all that oil and carbon can build up in the throttle body and FIAV causing it to fail in bypassing the extra air the engine needs to have to operate during cold starts

Take the TB apart and clean it out. If cleaning out doesnt help then you'll need a new bottom part of TB.

Thanks for your detailed response. I'll be cleaning out the TB with that special spray, hopefully that helps.

If not, where can I find a FIAV for a 4G63 throttle body? I googled and didn't see any reputable vendors.

 

[1G Eclipse94928]

Also is it safe to assume you havent done any hacking, deletes, removing stuff, or other mods like that?

Before you post the log make sure its reading the o2 sensor as others have said because if it isn't then thats still your problem. (wires could be broken in that case.)

 

[bo0st]

Also is it safe to assume you havent done any hacking, deletes, removing stuff, or other mods like that?

Before you post the log make sure its reading the o2 sensor as others have said because if it isn't then thats still your problem. (wires could be broken in that case.)

Yeah nothing stupid has been done to it. The 02 sensor is showing more activity but it doesn't have anything to do with the cold starts.

I'll start another log once I clean the TB out.

 

[MY1GDSM]

Shoot me an Email I'm sure I can sort it out

Though just too be clear as has been mentioned some things need to be addressed and we will have to discuss a few things.

 

[bo0st]

Shoot me an Email I'm sure I can sort it out

Though just too be clear as has been mentioned some things need to be addressed and we will have to discuss a few things.

Email sent.

Also I've attached the logs here (new from today after cleaning out the TB)

Also attached one jpg file that shows reported DTCs in ECMLink

"1400 - Manifold Differential Pressure Sensor malfunction"

Is this the cause of the problem?

 

[MY1GDSM]

So... You have a wideband.
But, don't want to hook it up... Makes sense

Good luck with sorting your issues out...

 

[bo0st]

So... You have a wideband.
But, don't want to hook it up... Makes sense

Good luck with sorting your issues out...

^ This guy is hilarious.

What's a wideband have to do with a cold start problem? Nothing.

Do you realize when the car gets hot, there's no problems? Obviously this is something related to the throttle body area and the wideband would be just a light show at that point.

The rule of thumb is to keep things simple while fixing the problems. Not adding stuff before fixing problems. I might as well add a 100 Shot of Nitrous while I'm add it.

Look at the other stuff, so many information is in link, but you're trying to get me to install my Wideband so you can SELL me a tune when I clearly told you in the e-mails I don't need a tune.

I don't need a tune bro and even if I did I wouldn't get one from you, you've got a couple negative iTraders there good luck with your business

 

[gofer]

Being a smart-ass to the few people that could potentially fix your problem probably isn't a good idea, you aren't going to get much help. MY1G isn't trying to take your money by asking you to log your WB, he's telling you to log it so we (not just him) can see what your AFR's are doing...

There's a reason for it, it may not have to do with your cold start but it will help us diagnose the problem. You've got a WB, why not hook up the single wire to your ECU to log it so we can see what your AFR's are doing while the cars cold and maybe fix the problem? Or don't and you can deal with this problem for another 5 years...

 

[bo0st]

Being a smart-ass to the few people that could potentially fix your problem probably isn't a good idea, you aren't going to get much help. MY1G isn't trying to take your money by asking you to log your WB, he's telling you to log it so we (not just him) can see what your AFR's are doing...

There's a reason for it, it may not have to do with your cold start but it will help us diagnose the problem. You've got a WB, why not hook up the single wire to your ECU to log it so we can see what your AFR's are doing while the cars cold and maybe fix the problem? Or don't and you can deal with this problem for another 5 years...

I have an AEM wideband and I was told they are so shitty they're not even worth logging, can I get your opinion on that??

 

[gofer]

Over the years I've probably tuned a dozen or so DSM's that had a AEM WB and about 75% of them logged accurately in Link, all others I had to setup the LinearWB settings to log AFR's accurately. You won't know either way until you start logging your WB though but, if you do have problems, here's a video I made to help someone who's car I was remotely tuning that was having logging discrepancies with his AEM WB.

https://www.youtube.com/watch?v=k3BIR6OOphg

 

[jery1234]

No wb is a bed or good, but you have to know how to calibrate it . You can use it as linear wb and get it woking perfet.