seems like no fuel in open loop?

[moneypit]

Did you perform a TB relearn after you cleaned it? This is to reestablish the idle position. Pull the CPAS connector and look for any oil in the connection, this would warrant a replacement. Do you have access to a vacuum gauge?

If you are referring to some type of esoteric steps needed to take other than disconnecting the battery...well unfortunately I used to believe there was such a proceedure but there is none I can find in the manuals. I have changed my position on that.




Aside from checking these things and since this is a 2002 I would consider replacing both the CPAS and camshaft position sensor as regular wear items. Those parts are really not worth the diagnostic fees many shops charge. You might be lucky and live near May03lt and he would bust out his scope. Which reminds me he had some stalling and so did I a while back. We replaced both items and the stalling is gone. But it could be a vacuum leak as well. Assuming everything runs well in closed loop I would not suspect fuel or ignition issues. Also check your coolant temps using a scan tool. Too high of a temperature reading when the engine is cold and the engine will not run right. It will run lean. Just my .02

SES light set a P0014 the other night & today I inspected & found a very light film of oil in cpas connector & a couple tiny pieces of "dirt?" on screen so I got a new one. $58.00 Reattached evap, testdrove twice without incident? Will check again in the am. always Mobil 1 at 5-6k too. I see they dropped the cpas price and also added some springs around screens

 

[moneypit]

So far so good although the weather has gotten colder here.......

 

[CaptainXL]

Well there you go. Our engines dont have an EGR valve. That duty is left to the CPAS now. If you had oil in the connector then it wasnt doing its job. Make sure you clean out the oil inside the connector itself when replacing the CPAS. Auto parts stores sell CRC QD cleaner/electrical contact cleaner in the short red and white can.

 

[moneypit]

well it hasnt acted up at all the past couple days...but the temp outside has fallen. If the stalling was caused by the faulty cpas, I'm glad it finally set the P0014 to alert me.

 

[moneypit]

took it out, ran descent but did feel a little something then when I came to the 2nd stop it stalled fine after that..as usual....

 

[moneypit]

Nah...still acting up! Starts in around 140 degrees or 1/2-3/4 mi. and continues until 200-210 or another 1/2 mile. I noticed when taking foot off gas & its gonna stall, lights flicker down dimly & back again as you work the gas to "catch it from stalling" & once stalled/starts right up and runs good? It acts exactly as jc8587's from TV & his was a new evap canister & solenoid valves...I just really hate to spend $200.00 on a "possibility"!

 

[CaptainXL]

OK it's video time. Can you make a film of what you are experiencing? It would help us out a lot. Thanks.

 

[moneypit]

OK it's video time. Can you make a film of what you are experiencing? It would help us out a lot. Thanks.

? I guess I'll try tomorrow.

 

[Harpo]

I am experiencing a similar problem but not so often.

The other day i noticed on my tourqeapp that my o2-sensor curve "flatlined" right before and when it stalled.

It occurs at the same time and temp as yours but not every time i start cold.

Mostly at temps around 10-15C 50-60F.

Do you have the Tourqeapp??


It seems to me that it falls out of closed loop into open loop again and the engine gets to much fuel it seems like to me, happend one day in my driveway standing still and i recovered the stall and it smelled like to much fuel from the exhausts.

I also get a P1441 on a regular basis.

 

[moneypit]

I found this today
TSB #03-06-04-057 10/01/2003

Intermittent Hesitation, Stumble or Idle Stall after Soak, Harsh 1-2 Shift, Slipping 1-2 Shift Followed by a Harsh Engagement (Reprogram PCM)

2002-2003 Chevrolet TrailBlazer
2002-2003 GMC Envoy
2002-2003 Oldsmobile Bravada
with 4.2L Engine (VIN S - RPO LL8)

Condition:
Some customers may comment on an intermittent hesitation/stumble or idle stall within minutes of starting after the vehicle has been sitting for several hours. Additionally, some customers with a 2003 model year vehicle may comment on a harsh 1-2 shift or 1-2 slip shift that has a bump feeling when 2nd gear engages.

Cause:
This condition may be caused by the EVAP diagnostic test as it opens the purge valve for a few seconds and then closes it to verify proper emission sensor operation. If the purge canister is saturated, the EVAP system on-board diagnostic test may cause the vehicle to correct for a rich condition from the canister. The vehicle would then become lean when the purge valve closes at the completion of the test. This condition occurs primarily with high RVP fuel and after the vehicle sits for several hours in a warm ambient, above 21°C (70°F). A customer who takes short trips is more likely to experience this condition, as they don't have the drive cycle that would allow the purge canister to fully re-circulate the fuel vapor.
This seems to be exactly whats going on with mine, it was very bad before my pcm reflash which seemed to help the severity but still exists. I've been tossin n turnin whether to get a new canister?

 

[CaptainXL]

Perhaps. But I would think a new canister would just get saturated again unless that update prevents that from happening. You may have to take it on a lengthy trip to see if it helps. This is because the purge solenoid opens the valve when you are cruising on the highway.

Just curious, do you ever "top off" the tank at all?

Also think about switching gas vendors.

 

[moneypit]

Perhaps. But I would think a new canister would just get saturated again unless that update prevents that from happening. You may have to take it on a lengthy trip to see if it helps. This is because the purge solenoid opens the valve when you are cruising on the highway.

Just curious, do you ever "top off" the tank at all?

Also think about switching gas vendors.

Hi, I get gas all over..no problem. I used to top off but havent in a yr. or so.. I've owned this for 3 yrs but has sat alot in the past 2 yrs. logging a mere 9k. It sat for the past 6mos for instance. This being the original canister "probably" & the known saturation tsb, and it being 10yrs old, I think it might be better to renew then to drive on a long trip in hopes of "airing it out". I'm not at all sure whether I should bother replacing the vent solenoid too? Tomorrow I'm gonna pull the canister and check it out, the websites are all over the place on the correct one for my 2002 TB ext. Not sure if I need a 215-415(17113682) or a 215-416(17113683).

 

[moneypit]

So I ended up pulling the tank(pita) and installed a new canister(215-416). Hasn't stalled yet but temps have gotten colder outside. Since the reflash, I do have a short window of "not smooth" running during the 1-2 mile warmup range...which can simply be "powered thru" with more gas pedal but with 166k on the internals I can live with that..for now especially since we don't even drive this truck too much.

 

[moneypit]

Would the EVAP canister or system cause these symptoms if saturated?

sorry to get back so late, been soo busy & not really driving the TB either-though stalling has gone From what I gathered..and read, "If the canister becomes saturated, then when the evap performs its' self test it will cause a very rich condition and lean the system" frpm that tsb dated 11/03! and since mine was not 1 yr BUT 13 yrs old, I figured why not..and all the vent solenoid failures I saw set a po440 iirc but I renewed that as well due to age. Looking back, I wish I hadnt got the pcm flash when I did because even though it made the TB more useable under the conditions it changed the way the engine runs during those first few minutes after cold startup negatively I believe. Also the thread from jc8587 @TV which went thru this with a positive outcome It was a gamble that I believe paid off.

 

[gmcman]

Cool deal, needless to say I hope your issue is fixed.

 

[moneypit]

Yea Thanks man. Its been a real adventure with this sob..lol

 

[moneypit]

Hi all, just wanted to update...been driving the truck alot and all is great! We havent been using the truck alot the past 2 yrs. which prolly accelerated this problem? Anyways, last thing I did which seems to have corrected my "1st 2 mi.stall" condition was a new Evap Cannister which on my EXT resides "above" the gas tank!