NEED HELP Engine stalling. No codes

yazan

Well-Known Member
The engine start stalling yesterday while accelerating from low speed or parking to drive.
Its ok in high speeds
And the idle is not fine or smooth. There is some hesitating and vibrating .
The stalling is only while pressing the pedal to accelerate at low speeds.
I have p0133 sine 2 weeks.
I have a crack in the exhaust making little sound.

Any suggestions. Deeply appreciate any advice.
 

Mooseman

Moderator
I would be more inclined to.think the O2 sensor is defective as most searches would yield for that code. It's giving a slow response, not a lean code.

Has the throttle body been cleaned? That can cause idle problems especially if the battery has been disconnected lately.
 
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yazan

Well-Known Member
I would be more inclined to.think the O2 sensor is defective as most searches would yield for that code. It's giving a slow response, not a lean code.

Has the throttle body been cleaned? That can cause idle problems especially if the battery has been disconnected lately.
Yes. Tb cleaned. first thing I did.
Do a bad o2 sensor cause engine stalling?
Today noticed that its not about drive only. Even at idle when I press the pedal slowly the engine making hestating between 1.5 - 2 rpm but not stalling. Only while driving at low speeds like turning in the roads and traffic stop.
 
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Mooseman

Moderator
You could try disconnecting it and see if it improves. That way the PCM will ignore the O2 sensor and just use pre-determined tables for fuel. One way or another, I think it's defective.
 
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yazan

Well-Known Member
You could try disconnecting it and see if it improves. That way the PCM will ignore the O2 sensor and just use pre-determined tables for fuel. One way or another, I think it's defective.
You are great man
I just try that and no more stalling. I drive for 3 minutes with no stalling at all
So that mean its defective?
I removed the cat years ago And disabled the code when I orderd from pcm4less .is this related to the current problem?
 

Mooseman

Moderator
Yes you should replace the upstream sensor. Otherwise, your fuel consumption will likely increase and the engine will not be running optimally. I`d leave it like that only as a temporary measure.
 
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yazan

Well-Known Member
Sorry. Today replaced the o2 sensore upstream. It was ordered and take a time.

After replacing the sensor I drive for 10 minutes then stop at traffic stop and the I got hesitating and vibration with pending p0014 p1345
I noticed when I start the ac . the rpm fo higher. More than 1000 ~1200 then start going down slowly.

This car Realy drive me crazy
 

Mooseman

Moderator

Mooseman

Moderator
No. I would suspect a vacuum leak for that or a defective brake booster. Check the hose to it as well as the check valve. May also be what's causing the driveability issues as well. If there is a vacuum leak, it should eventually throw a lean code.
 
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yazan

Well-Known Member
The weird thing. That the problem not all the time. I just drive about 10 minutes back to home. Nothing happened!
Tomorrow o will clean both sensors cpas and cps.
And I will check th wiring .this codes just set after replacing the Upstream o2 sensor
 
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yazan

Well-Known Member
sorry .please accept my apology… guys ineed your help please @Mooseman @MRRSM I run to another problem today. Ignition switch. Ithink.!

After doing replacing the wire harness for the cpas and cps . also I swapped the pcm with old one "i said may be I have bad one"
And cleaned the battery terminals and cables . Ground point near the battery and the one under the mid console inder hvac unit. Passenger side.
And the terminals in the both fuses box "front and rear"
So when finished I start the car and it run good for about 10 minutes woth no codes. I did on and off 4 times and pressed the pedal to rise the epm . no codes…iam not sure yet if p0014 p1345 I fixed now…. .. then suddenly engine stall with no codes.
I see that no trany selection in the dash (p.r.d.1.2.3) The clusters also was funny .
I try to start but no luck.
The scan tool cant connect to the car.
So I did the big mistake. I removed the igintion switch while key in and battery connected and didn't mark the gears position!!
How that happened! I replaced the ignition switch before years bit I forgot the gears marking.

Now I disconnected the battery. And waiting for tomorrow to buy a new ignition switch
But I need your help guys what to do ?


Also today I got another obd scan app. That show more codes. So many! U1000 and b3811 and others ..
 
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Mooseman

Moderator
These might help:



You should be able to figure out which positions are what on the switch. As long as you don't have the key itself turned to any other position than OFF, you should be able to figure it out. The guy in the video, I would assume, his switch is in the OFF position so you could try in the same position as his.
 
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yazan

Well-Known Member
I got failed with the ignition switch position until I start considering my broblem isn't with the innocent ignition switch. The position and the gears i think is fine. Because when the key is off there is no power in accesories or door panel and windows.
The only thing is the trany indicator in dash board. It still no selection at all.

Is there any thing could cause this. No cranck no trany indicator !
 
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Mooseman

Moderator
Maybe try putting back the PCM you had before. Maybe this one is/has gone bad or is not compatible with this replacement engine. Then check all your fuses and grounds. From memory, when the PRND321 indicator doesn't work, there is a power issue either from the ignition switch or a ground.

Edit: Remembered this video which shows how to test at the switch. Video is cued to the appropriate time for testing without a Tech 2 scan tool.

 
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MRRSM

Lifetime VIP Supporter
@yazan... To reply to your PM in the post you linked back here... I Agree with @Mooseman 's latest suggestion. Download the Video... and then use VideoLan (VLC) to Play the Video Back at a Much Slower Speed as often as you need to learn these procedures.
 
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yazan

Well-Known Member
very helpful video thanks , downloading now , actually i believe its not that difficult , i did it before and i think i did it right today .. i start thinking not the ignition switch is the cause
i found this pdf file about replacing the ignition " attached"
and i think no need to remove the cylinder but i did it this way .

i was thinking about the replacement pcm i installed .. but "i asked myself" if its the pcm so why it start for long time then stall suddenly ? and then the PRND321 indicator didn't work any more does it need a security relearn ? i have @Mooseman replay in my old topic, i will try

i read somewhere about jumping wires in fuse box , " i think starter relay" to bypass the ignition switch and test if its a pcm issue or else , but i lost the link to that website , i will keep searching
 

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yazan

Well-Known Member
Just swapped the pcm . no effect.
Checked the ignition switch power as video and jump the orang to the pink wire and no luck

And my both scan tools still can't communicate with the car...
update: I notived something new today. When the key in start position ./ accesories. There is tickin sound all over the doors. Theliftgate. And the lights in door panel also flickering while ticking. ! And some tims can't open/close the windows,
 
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Mooseman

Moderator
How is the battery? Does it have a full charge? A lot of weird stuff can happen with a bad or weak battery. You should get it tested.
 
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yazan

Well-Known Member
ok guys , i think i fix it ' engine now is running , i keep it running for 30 minutes, i switch it off many times to check , scan tools now can communicate with the car , PRND321 now working
i didn't try to make drive test , i was tired , long day diagnosing ,

i will write extended post for any one how will get similar problem ,,

the ignition switch was fine and i tested it with help up from our heroes @Mooseman @MRRSM here and another topics i read ... and this post by roadie

the damaged wires shown up in post fixed but wasn't the reason for no crank or no prnd321
but i have more better situation and feeling also ,

the main problem was the grounding point in the engine - driver side between the stater and coolant outlet

i describe the location with red circle in this image i attached
ground.jpg
how i know ?
i run the ignition to start position and start checking again and again, when start inspecting the pcm wiring harness and see the cracked wires, i noticed the pcm will have power and make that ticking sound when i start jiggling the wiring harness and i noticed a fast ticking sound from top of the engine - not throttle - and that ticking sound go way when i shake or wiggle the harness , so i start looking for broken wire , until i found that the grounding is rusty and loosing connection
i mad a YouTube video for that . here its

then after that i have prnd working , no "check brakes" or check abs on dtc.
Bit I still cant crank . so I test the fuses again andvi dound 2 blown fuses. Onewas foe the pcm and the other is accessories.
No the engine run and crank good . obd connection ..

Bit o still have some troubles. The rpm was funny and playing arround. Figured its thw white wire in the pcm harness. Ok its better but not fixed because I played with the cluster a bit when I removed the cluster unit. And think it need replaced or calibrated.

Alo I still have the ticking sound in doors panels and the lift gate and losing the power in them and when I lock the doors its keep locking for 4/5 times .
I glad that th enginevis running. I hope it will still. I jist replaced the engine with used one before 2 months and warranty finished.

I will keep updating here and see the next days if it will stay good.

My advice for who have similar problem;
1- start with basic /simple things , dont jump up"like i did" to the big things like replacing pcm or dashboard or bcm or lgm or PRND321 switch or any thing else until you have done the simple things
2- keep testing the fuses again and again after doing any fix

Soo many thanks for this forum and especially for Heroes @Mooseman @MRRSM words is not enough… for helping here and there helpful answer's arround the forum . also for roadie and my03lt
 
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MRRSM

Lifetime VIP Supporter
Congratulations, @yazan ... You are Living Proof that Sheer Determination CAN Conquer Major Automotive Diagnostic Problems. When time permits... I'm certain that @Realism would appreciate having you Post a Message linking back to this work on his Excellent Topic of "Ground Locations" at the Link Below as a PERFECT Example of just how critical it is that Good Grounds must be maintained... and just How Many Things can GO CRAZY...when they Do Not have Good Connections...

You Finally SOLVED.jpg This Problem ...On Your OWN, Brother!

 
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Mooseman

Moderator
Just so to not jinx it, I will hold off marking it solved.

Good detective work on that PCM wiring. I suspect the shop that installed your engine for that since there is not natural way for the wires in there to get like that. It could have contributed to the issues. As well, that ground was probably not installed correctly by that same shop.

For the LGM, it could be broken wiring in the liftgate wiring boot. Open it up and tug and pull on each wire. It might not be visibly aapparent as they usually break inside the plastic insulation.
 
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yazan

Well-Known Member
Just so to not jinx it, I will hold off marking it solved.

Good detective work on that PCM wiring. I suspect the shop that installed your engine for that since there is not natural way for the wires in there to get like that. It could have contributed to the issues. As well, that ground was probably not installed correctly by that same shop.

For the LGM, it could be broken wiring in the liftgate wiring boot. Open it up and tug and pull on each wire. It might not be visibly aapparent as they usually break inside the plastic insulation.
Thanks..
I checked the voltage at the orange wires. It have power. And I wiggled the harness inside the isolation tube and the sockets. Seems to be fine.
Btw. The remote fob sometimes not working.is it related to this also? And the fob related to lgm or bcm(that under rear seat)?
 

Mooseman

Moderator
The fob works through the LGM. Just juggling the wires isn't enough. You hhave to pull the boot and then pull on each wire.
 

MRRSM

Lifetime VIP Supporter
Have look at Post #s 25, 26, 31 and 37 at this Link for information about the (LGM) Lift Gate Module Design and Wiring Harness Connector Layout and Download to View the attached Class 2 Network Wiring Diagram that will define the LGM Network Circuitry and tell you what to probe for continuity.

https://gmtnation.com/forums/threads/how-to-make-a-gymko-tech-2-bench-top-test-harness.18272/

And just in case you need more places to look for trouble regarding the Key Fob Issues… watch this Video that covers the “Pass Through” Wiring between the SUV Roof-Body Tubing and out into the Lift-Gate itself servicing the LGM, The Rear Window Latch and the Windshield Wiper Motor.


As for the P0013 and the P1345 Codes... These are probably the most troubling because they indicate a problem with the PCM trying to correctly correlate and reconcile the Timing and Positions of the Crankshaft and Camshafts in order for the PCM to know when to Fire the Spark Plugs within a correct BTDC (Before Top dead Center). GM's Solution for this problem as a final fix was to tell their Customers that they should "Replace The Engine".... Talk about Nightmare Engineering. The Replacement Procedures of the Camshaft VVT Phaser and Timing Set is the only way out of this problem and is well documented by @Mooseman here:

https://gmtnation.com/forums/threads/how-to-replace-the-cam-phaser-aka-vvt-actuator.14924/

Anyway... This first Video covers the Diagnosis of the P0013,P0014 and P1345 problems of Crankshaft-Camshaft Correlation. The VOP examines the CPS, CPAS looking for problems that the Cam Phaser, Timing Chain, Timing Chain Guides and Timing Chain Tensioner have worn enough to require a complete replacement of the Timing Chain Set. Hopefully, it will not come to this...as this is a VERY Complex repair because in order to access these Timing Components... unless you Pull the Motor... you have to Remove the Crankcase - Oilpan just to be able to Remove the timing Chain Cover. Look up GMTN Member @Kevin Nadeau on Youtube for his (5) Part Series for a Bird's Eye View of everything he goes through while performing this arduous job.


 
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yazan

Well-Known Member
Have look at Post #s 25, 26, 31 and 37 at this Link for information about the (LGM) Lift Gate Module Design and Wiring Harness Connector Layout and Download to View the attached Class 2 Network Wiring Diagram that will define the LGM Network Circuitry and tell you what to probe for continuity.

https://gmtnation.com/forums/threads/how-to-make-a-gymko-tech-2-bench-top-test-harness.18272/

And just in case you need more places to look for trouble regarding the Key Fob Issues… watch this Video that covers the “Pass Through” Wiring between the SUV Roof-Body Tubing and out into the Lift-Gate itself servicing the LGM, The Rear Window Latch and the Windshield Wiper Motor.


As for the P0013 and the P1345 Codes... These are probably the most troubling because they indicate a problem with the PCM trying to correctly correlate and reconcile the Timing and Positions of the Crankshaft and Camshafts in order for the PCM to know when to Fire the Spark Plugs within a correct BTDC (Before Top dead Center). GM's Solution for this problem as a final fix was to tell their Customers that they should "Replace The Engine".... Talk about Nightmare Engineering. The Replacement Procedures of the :Banghead::Banghead::Banghead::Banghead: is the only way out of this problem and is well documented by @Mooseman here:

https://gmtnation.com/forums/threads/how-to-replace-the-cam-phaser-aka-vvt-actuator.14924/

Anyway... This first Video covers the Diagnosis of the P0013,P0014 and P1345 problems of Crankshaft-Camshaft Correlation. The VOP examines the CPS, CPAS looking for problems that the Cam Phaser, Timing Chain, Timing Chain Guides and Timing Chain Tensioner have worn enough to require a complete replacement of the Timing Chain Set. Hopefully, it will not come to this...as this is a VERY Complex repair because in order to access these Timing Components... unless you Pull the Motor... you have to Remove the Crankcase - Oilpan just to be able to Remove the timing Chain Cover. Look up GMTN Member @Kevin Nadeau on Youtube for his (5) Part Series for a Bird's Eye View of everything he goes through while performing this arduous job.


OMG , i just replaced the engine 2 moths , here is the details

i am afraid getting same troubles as in the previous engine because a problem elsewhere the engine "mean to say not the engine " , electric or any thing else
the engine was fine since replacement , only i got this problems : knock sensor - it was a bad wiring ( broken) and then with o2 sensor - just replaced and the grounding engine wire was loose

i just cleaned them when doing the above diag, i will check budget for replacing both cpas and cps


OMG OMG OMG
Camshaft VVT Phaser and Timing Set
please hopefully no no nooooooo

:Banghead::Banghead:
 
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MRRSM

Lifetime VIP Supporter
With that Recent Engine R&R in Mind... With The Engine OFF...Slide under the Driver's Side of the Vehicle and Double Check that the (CKP) Crankshaft Position Sensor mounted in the Left Side of the Engine Block has a really Good Harness Connector Attachment.

I'm beginning to suspect that your Replacement GM Atlas LL8 4.2L Engine...was NOT pulled out of a Vehicle that was involved in an Accident and Running at that time.... But rather one that was simply Pulled and Placed on a Stock Shelf to be Sold As IS later on because the P0013 and P1345 proved to be too much for the Prior Owner to deal With..
 

MRRSM

Lifetime VIP Supporter
Yes....

(1) The CPS (Camshaft Position Sensor) is located in the Front, Just underneath the Valve Cover on the Outer Block and is held in with 10MM Bolt. Its Job is to MEASURE THE ABSOLUTE POSITION OF THE EXHAUST CAMSHAFT.

(2) The CPAS (Camshaft Position Actuator Solenoid) is located just behind the Power Steering Pump Assembly on the Passenger Side of the Engine Head. Likewise ...it is held in place with a 10MM Bolt. Its Job is to use an Electro-Magnetic Pin that slides and 'shuttles' in and out to allow Engine Oil to Pass into and out of the Camshaft VVT (Variable Valve Timing) Phaser.

The Motor Oil first passes through a series of Stainless Steel Fine Mesh Screens in order to Filter out Large Pieces of Dirt and Detritus that would otherwise Clog up the Insides of the Cam Phaser. This Device allows for Infinite Advance and Retard Variability between "0" to "25" Degrees of Exhaust Camshaft Rotation.

This makes it possible to change the Power Band and Torque in a spectacular way that gives this In-Line 6 LL8 Engine a MUCH wider Performance Band... up and down from the Low to High RPM Scale. When the Screens get Clogged ... The PCM has NO Way of detecting such problems... and the Engine will Stagger when Idling and loose Power at Higher RPM levels because the VVT action of the Cam Phaser becomes impeded.

The CPAS, CPS, CKP, MAF, TPS, ACC and O2 Sensors constantly inform the PCM as to when to Precisely Fire the Spark Plugs (BTDC) and adjusts the Fuel Delivery using PWM (Pulse Width Modulation) signalling to the (6) EFIs and strives to achieve the Cleanest Burning 14.7:1 A/F conditions. By performing well In this manner... the GM Atlas Engine Camshaft VVT Phaser System also eliminates the need for an EGR (Exhaust Gas Re-Cycling) Valve.
 
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Mooseman

Moderator
Have yyou had a CASE relearn done when the engine was replaced? Unless the shop has access to a high end scanner, it might not have been done. I would try this before diving any deeper into it. Check with the shop. If they did, I would plead with them to fix it under warranty despite being beyond the 30 day period as a good will gesture or at a reduced cost.
 

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