2002 TB 4.2 died at stop & immediate restart

[movietvet]

This 2002 TB with 72k miles has been running great and been very dependable for her. She is about 350 miles away right now and driving back tomorrow. Today, out of nowhere, at a stop light the engine died, like a light switch shut off. Not any notice and did not die like starving for fuel. She put in Park and immediately restarted and drove 20 miles back to where she is staying with no problems. History: Within last 2k miles: new GM iridium plugs, new GM air charge temp sensor in the air snorkel tube, new GM water pump and new GM thermostat/water outlet assembly, new GM ignition switch-there is a thread here about that journey. New GM fuel filter. Cleaned throttle bore and MAF.

This vehicle starts up immediately and runs smooth and strong and just today was the only hint at a problem. She did not even feel it die. She went to accel from a stop light when turned green, realized had died, put in park and cranked normally and started right back up and ran fine getting back.

I do not suspect ignition coil because is not a misfire but I guess could be a ground for the ignition coil circuit. I told her to drive home tomorrow and keep an eye on all gauges. I also suspect a cam or crank sensor and will likely go ahead and do both anyway. have them in a cart at RA right now. Can anyone tell me the location for the ignition coils ground? Tell me any helpful hints for replacing the cam and crank sensors? Tell me about a similar "engine die at idle" problem and what was done to fix?

Thanks in advance.

 

[Mike534x]

I had a similar issue with my 02 Envoy years back, where it would randomly die slowing to a stop light/sign, or pulling into the driveway before putting her back in park. It would start up and idle perfectly fine everytime, with no hiccups or CELs. After searching on the old site before this one was formed, I found a few threads at the time with others experiencing similar issues. Turns out it was the CPS (camshaft position sensor), I bought mine at the time off Amazon (Delphi SS11913) and drove her around for a few hours and it never happened again.

The CPS sits at the very front of the engine/lip of the valve cover below the oil cap. Takes I think a 10mm, and slides right out without having to remove/move anything out of the way.

 

[TJBaker57]

Cleaned throttle bore and MAF.

2002 didn't have a MAF. MAP sensor maybe?

could be a ground for the ignition coil circuit

The 6 coils are powered through ignition switch and fuse 28 and the grounds are at G109 on the side of the engine. All 6 coil power and all 6 coil ground wires run separately back to the fuseblock where they join up before running to the fuse or ground.

suspect a cam or crank sensor and will likely go ahead and do both anyway

Replacing the crank sensor will require a relearn. That requires a capable scantool.

 

[mrrsm]

Agree with Tom ( @TJBaker57 ) regarding the possibility of having a Shorted Coil Over Plug. Any Coil that Dead Shorts will Kill the Engine Stone Dead until it Manages to COOL Down enough to at least work temporarily.

Please Read Post #s 16,17,18 and 26,27 and 28 in THIS Thread for the Deeper Dive into How to Diagnose the REAL Cause and Origin of this issue (Lean Cylinders Adding Stress to the Secondary Ignition and Failing Spark Plugs, with Carbon Tracing occurring along the Rubber Boots, etc.)

How To Use PICO #2204A & HANTEK #1008C Oscilloscopes

You don't need a Huge Bag of Coins in order to obtain and use an Oscilloscope for performing In-Depth Wave Form Analysis in Automotive Applications on everything from Problematic Electronic Fuel Injection to obtaining accurate Compression Tests to Diagnose Internal Engine Conditions. HANTEK...

gmtnation.com

 

[movietvet]

2002 didn't have a MAF. MAP sensor maybe?




The 6 coils are powered through ignition switch and fuse 28 and the grounds are at G109 on the side of the engine. All 6 coil power and all 6 coil ground wires run separately back to the fuseblock where they join up before running to the fuse or ground.





Replacing the crank sensor will require a relearn. That requires a capable scantool.

View attachment 109958

There is info out there that some crank sensor manufacturers product does not require a relearn process. Found that Standard, Beck Arnley and Delphi crank sensors do not require a relearn process. Does that sound correct? I have used Delphi products in the past with great results.

 

[mrrsm]

Probably not... The CASE relearn solves a LOT of Problems to reconcile the relation between the (CMP) (Camshaft Position Sensor (absolute)) and the (CKP) Crankshaft Sensor. The Disgruntled Mechanic uses an Autel Maxi-DAS DS-708 to perform the Re-Learn in THIS Video:

 

[TJBaker57]

There is info out there that some crank sensor manufacturers product does not require a relearn process. Found that Standard, Beck Arnley and Delphi crank sensors do not require a relearn process. Does that sound correct? I have used Delphi products in the past with great results.

No, it does not sound correct at all.

The service literature even goes so far as to state that the relearn is required even in the absence of the P0315 code when the CKP has been replaced.

The relearn is required when any part of the rotating mass has been altered, repositioned or replaced even down to the harmonic balancer bolt.

 

[movietvet]

I did ask her yesterday if there were any CEL or lights that did not look normal. She said no and as I said yesterday, she put in Park and the engine restarted right away, idled normally and she drove the last 20 miles with no problems. She will be heading home today. I may or may not find any codes. I hope I do and can track them but shall see when she gets here.

 

[movietvet]

No, it does not sound correct at all.

The service literature even goes so far as to state that the relearn is required even in the absence of the P0315 code when the CKP has been replaced.

The relearn is required when any part of the rotating mass has been altered, repositioned or replaced even down to the harmonic balancer bolt.

Yea, I am sharing what I saw on you tube. One guy addressed the relearn yea or nay question. The rest just showed the r&r procedure. I have access to a Tech II and a Foxwell scanner, so I will do a relearn if needed. One guy did mention the relearn and he said that he pulled PCM fuses for 15 minutes and/or disconnected battery for a day and it accomplished the same thing. Not quite buying that. I do have a friend that is very versed about this and he will talk me thru it or show me.

 

[TJBaker57]

Many "History" codes can remain stored for as many as 100 ignition cycles so if there was a code that sets the history status it may still be present. Then it can become a question of if the scantool in use reads history codes.

Unfortunately these sorts of intermittent issues often do not set any codes at all.

 

[TJBaker57]

One guy did mention the relearn and he said that he pulled PCM fuses for 15 minutes and/or disconnected battery for a day and it accomplished the same thing. Not quite buying that.

The great fault of Youtube and the like is the vast amount of erroneous 'information' present.

The trouble with this relearn thing is that there is no reliable way to determine the need other than depending on the actions taken, like replacing a CKP sensor.

Just because the engine appears to run OK is not sufficient to say that the PCM can accurately detect a misfire in a given cylinder, or properly deliver fuel and spark at the optimum microsecond it is needed.

 

[movietvet]

The great fault of Youtube and the like is the vast amount of erroneous 'information' present.

The trouble with this relearn thing is that there is no reliable way to determine the need other than depending on the actions taken, like replacing a CKP sensor.

Just because the engine appears to run OK is not sufficient to say that the PCM can accurately detect a misfire in a given cylinder, or properly deliver fuel and spark at the optimum microsecond it is needed.

Yea, I don't have access to the Tech II and Foxwell scanners, to just forgo using them and doing a battery disconnect. If I do the crank sensor, the relearn will be done with one of these scanners.

 

[TJBaker57]

 

[Mooseman]

Just reading the initial post, I'm also thinking of the fuel pump, either it's starting to fail or an intermittent wiring issue. You know when it's failing and hitting the tank brings it back to life temporarily, that kind of failure. Maybe the action of shutting off and then back on brings it back.


Anyway, just another possibility to look at.

 

[TJBaker57]

Back to the issue as described, I would be more inclined to examine and refresh possible electrical faults such as dirty grounds, loose fuse sockets and the like.

Back in '85 I factory ordered an '86 Pontiac Trans Am with 5 liter V8 and all the goodies. After a few years I started getting a 'hiccup' after about 15 minutes of operation that presented as a momentary multi cylinder misfiring. After the event the vehicle ran flawlessly for the rest of the day. All scans showed no codes at all. Eventually after a year or more of this randomly happening the car died in the parking lot as I arrived home from work. I pushed it into a spot and decided I would have it towed to a friends shop and dig into it in the morning. The next morning it started and ran fine so I drove it to the shop and began checking things. These were the days of finding service informations in the "Motor" manuals and I Iocated wiring diagrams for the vehicle. In my perusal I noticed a lone inline fuse all by itself. Located up by the upper radiator support. This fuse was in the main power line to the ECM. I located this fuse holder and pulled open the rubber sealing cap and in removing the fuse found it had been mis-installed at the factory. Instead of inserting into the female socket the fuse was slid up alongside of the socket. The connection had deteriorated and heated to the point of the fuse plastic being cracked and warped and the terminals were badly pitted. So what had been happening I guessed was the poor connection would heat things up and generate a little expansion or whatever that caused a momentary interruption in power to the ECU.

Also back in those days it was not so uncommon for a vehicle to die and fail to restart only to start and drive fine after an hour or so. ECUs and HEI coils and such would fail when hot.

Your symptoms don't really point to such a fail-when-hot scenario since it restarted fine right away.

But a suspect power or ground connection may do this. This platforms fuse blocks have occasionally caused such issues.

 

[movietvet]

Yea, I asked her if it shut off like a light switch or did it "stumble/shudder/shake/cough" at all, like a fuel delivery problem. She said, it always idles smoothly. "I was sitting there at the stop light and when changed to green and tried to accelerate away, it did nothing. I then noticed engine was not running and I put in park, engine cranked normally and fired right up and I put in drive and accelerated normally and continued driving". She said she felt nothing that indicated the engine died. I of course will check fuel pressure when she gets home and inspect for dirty/corroded/loose grounds and inspect the connections at the cam and crank sensors. I will post my findings here.

 

[mrrsm]

Following on with @Mooseman's notion of an Intermittent Fuel Pump easily visualized with a PICO-Scope Model 2204A (or a Hantek Model# 1008C) and a Low Amperage Clamp... Great BAD vs. GOOD Known Fuel Pump Wave Forms gives a definitive diagnosis:

Known "BAD" Fuel Pump Wave Form (Missing large segments of Commutator Contacts):



Known "GOOD" Fuel Pump Wave Form (Even, Jagged Edged Commutator Activity)



Side By Side...



When the Pump gets CAUGHT in the No Contact areas ...The Fuel Pump either DIES...or will NOT Re-Start until you give the Gas Tank a Good *Thump* on the Bottom of it:

 

[christo829]

My old Lumina did this when the fuel pump was failing. It would seem to run fine, but after everything got warmed up, it would intermittently die as soon as I hit the gas to come off a stop. I checked the fuel pressure at startup, and it was fine, but after the vehicle had warmed up, fuel pressure dropped to roughly half of what it should have been.

When it did die, I could pop it in to neutral, restart it, and get going without any hesitation.

So check the fuel pressure at startup and also after warmup, and see if there's a difference.

I also noticed that my fuel pump started getting noisy as it warmed up. It sounded fairly normal at startup, but the whine was noticeable after warmup.

Good Luck!

Chris

 

[movietvet]

It died while idling and was like a light switch shut off. No chugging/coughing like running out of fuel. She did not "notice" the engine had died till she did try to accel after light turned green.

 

[mrrsm]

I know that I am in Danger of Repeating myself with THIS Particular Theme... However, it might be worth a try in THIS No Start situation, too:

(1) Pull the Top Cover(s) Off of the Fuse Box.
(2) Unbolt the Three 7mm Galvanized Studs restraining the Under Harness Blocks.
(3) Pull EVERYTHING apart and Spray EVERYTHING out with the CRC Electrical Solvent.
(4) Allow All of the Components to Fully DRY and then Re-Assemble the R&R.
(5) Try to Start the Vehicle...

 

[movietvet]

I know that I am in Danger of Repeating myself with THIS Particular Theme... However, it might be worth a try in THIS No Start situation, too:

(1) Pull the Top Cover(s) Off of the Fuse Box.
(2) Unbolt the Three 7mm Galvanized Studs restraining the Under Harness Blocks.
(3) Pull EVERYTHING apart and Spray EVERYTHING out with the CRC Electrical Solvent.
(4) Allow All of the Components to Fully DRY and then Re-Assemble the R&R.
(5) Try to Start the Vehicle...

View attachment 110080View attachment 110081

Great idea but the problem was a "died at idle" and did restart immediately with no problem and since that happened, there has been no problems at all.

 

[movietvet]

2002 didn't have a MAF. MAP sensor maybe?




The 6 coils are powered through ignition switch and fuse 28 and the grounds are at G109 on the side of the engine. All 6 coil power and all 6 coil ground wires run separately back to the fuseblock where they join up before running to the fuse or ground.





Replacing the crank sensor will require a relearn. That requires a capable scantool.

View attachment 109958

Yes, does not have a MAF. I gave erroneous info was the MAP I cleaned. Sorry for the wrong info. Amazingly enough, RA lists a MAF and a MAP for the 2002 TB.

 

[movietvet]

I have felt failing or failed fuel pumps before and there was always a chugging/coughing/sputtering effect when that happened. She did not experience that and that led me away from the fuel pump. It has performed flawlessly during her 300 mile return trip and all around town since back. I am going to do a fuel pressure test later today when it warms up a bit around here. Is 31 degrees right now and since the test port is under the vehicle, I don't feel like crawling around on the ground right now. Will be 55 degrees this afternoon.

 

[movietvet]

The first pic shows the KOEO after I started and shut it off. Before I started it, the pressure was this, after started was 53 psi and then the first pic shows what it was reading when I shut the engine off. The second pic is the reading/psi after shut off and sat for 1 hour. Unless the problem is very intermittent, the fuel pump is not a worry at this point.

After me buying a 2006 GMC Yukon Denali XL with 136k miles, less than a week ago, may be selling the TB anyway. Not gonna put more money in it unless I have to.

 

[TJBaker57]

After me buying a 2006 GMC Yukon Denali XL with 136k miles, less than a week ago

Is that a 4.8 or 5.3 engine in that Yukon? Are you aware of the Castech 706 head issue?

 

[movietvet]

Is that a 4.8 or 5.3 engine in that Yukon? Are you aware of the Castech 706 head issue?

It is the 6.0 engine, a 366 cubic inch engine. Yes, I am aware of the Castech head issues. I have that on my list, to check the head casting numbers.

 

[TJBaker57]

It is the 6.0 engine, a 366 cubic inch engine. Yes, I am aware of the Castech head issues. I have that on my list, to check the head casting numbers.

I don't think the 6.0 engines were affected, at least from the TSB I read.

 

[movietvet]

#06-06-01-019B: Information on Gradual Coolant Loss Over Time with No Evidence of Leak Found - (Jun 12, 2007)


Subject: Information on Gradual Coolant Loss Over Time With No Evidence of Leak Found


Models: 2004-2006 Buick Rainier

2001-2006 Cadillac Escalade Models

2001-2006 Chevrolet Avalanche, Blazer, Silverado, Suburban, Tahoe, TrailBlazer Models

2001-2006 GMC Envoy, Jimmy, Sierra, Yukon Models

2001-2004 Oldsmobile Bravada

2005-2006 Saab 9-7X

with 4.8L or 5.3L VORTEC® GEN III, GEN IV V8 Engine (VINs V, T, M, B, Z -- RPOs LR4, LM7, LH6, L33, L59)

 

[movietvet]

I just searched for and found this. The 6.0 heads are safe.

 

[movietvet]

Well, I have an update on the 2006 GMC Yukon Denali front. It was bought in hopes of trimming down our "fleet". My girl has a 1990 Chevy K2500 pickup with 129k miles on it and the 2002 TB with 72k miles on it. The Denali XL was supposed to take the place of both of those vehicles. She does not like driving the Denali. It took a while but we figured out the reason. It is just too big, "INSIDE". She does not like the cavernous feel inside the Denali. She likes the more enclosed feeling inside the TB and the extended cab pickup.

So, now I am going to sell the Denali and hope to get my money that I paid for it, back out of it.

It is a 2006 GMC Yukon Denali XL and it does not have the 706 Castech heads. It has the 6.0 engine 317 heads on it. I am just waiting about 2 weeks for the new title to get here and then I will post for sale. It is a PNW vehicle and has no rust problems. Very straight body with 136k miles on it. I paid $10k for it and that is what I want back.

 

[TJBaker57]

My lady also does not like driving my 2005 Yukon. She does like the TrailBlazer and her 2008 Ford Ranger. Same thing, the Yukon is too "big".

 

[movietvet]

Here is the link at my local CL for the sale of the 2006 GMC Yukon Denali XL. 24 pics here.

craigslist - account log in

 

[movietvet]

My lady also does not like driving my 2005 Yukon. She does like the TrailBlazer and her 2008 Ford Ranger. Same thing, the Yukon is too "big".

Yes, my girl used the term "cavernous" to describe the feeling. I truly believe that it could have to do with an uneasy feeling about a person hunkered down in there hiding from her. Plus, I think it also has to do with all the movement she would need to do to access the two rear doors and the rear hatch.

 

[Mooseman]

Here is the link at my local CL for the sale of the 2006 GMC Yukon Denali XL. 24 pics here.

craigslist - account log in

I'd recommend reposting to the vehicles for sale section with a proper link (this one is a link to your account management).

 

[6716]

I've had the "shuts off at stoplight but fires right back up" for several years now. It seems like it is more likely to happen with the blower going on 4 or 5, but that is just a sense I have. My current theory is that it's electrical, specifically not enough power supplied, but I don't think it's the alternator as the root cause. I am going to order a new tensioner pulley, idler pulley, and belt. When I went to replace the belt a couple of weeks ago the tensioner was much harder to manipulate than I recall it being previously. And, I've never replaced the tensioner in 16 years. I'm on the site today to find a rockauto code.

All in all, it hasn't been a huge problem for me, more like an occasional annoyance. It will be hard to say whether this fixes it or not, since I'll just be waiting for it to happen again. And anyway the tensioner is likely good maintenance regardless.

 

[mrrsm]

@6716 ...If it's not too much of a hassle... Pull the Air Box-Inlet off of the Throttle Body and while you are looking inside of the TB for a Dark Brown, *Sticky* Dirt and Gunk Ring around the Plenum Venturi Opening vs. the Butterfly Plate... also give "The TOPS of The COPS" a very close inspection ...looking for signs of changes in the appearance of one or two COPs on their Little Aluminum Radiators.

If you see one that looks particularly different... begin to suspect that it has been OVERHEATING. Check out whether your Misfire Counts coincide on THAT particular Cylinder and you might be nursing along a Bad Coil that only raises its Ugly Head and Shorts to Carbon Tracing on the COP Rubber Boot whenever the A/F Leans out just a bit too much. Just an FYI... Having LEAN BTDC Conditions can ruin Coil Over Plugs in this manner... and not the other way around of having a Bad Coil as the cause of this issue.

This Stuff is Everybody's BFF when it come to Cleaning Out Throttle Bodies:

https://www.amazon.com/dp/B0002KKIDW/?tag=gmtnation-20

Also... Double Check ALL of the Grounds and Bonding Cables between the Engine Block and the Frame...AND...your closely examine the Power and Ground Battery cables too...For any signs of Cupric Oxide (Green Corrosion). They will need replacing if they are infected up inside of their Connection Eyelets. Apply a Small Dab of Dielectric Grease in between their cleaned up Contact Surfaces to prevent future Galvanic Corrosion from increasing Electrical Resistance.

Electrical Ground locations

While troubleshooting a bad ground I came across some scans of the service manual regarding electrical ground locations for our platform posted on another site. This includes both short and long wheel base, as well as both 4.2L and 5.3L. Credit goes to Wex...

gmtnation.com

 

[movietvet]

I've had the "shuts off at stoplight but fires right back up" for several years now. It seems like it is more likely to happen with the blower going on 4 or 5, but that is just a sense I have. My current theory is that it's electrical, specifically not enough power supplied, but I don't think it's the alternator as the root cause. I am going to order a new tensioner pulley, idler pulley, and belt. When I went to replace the belt a couple of weeks ago the tensioner was much harder to manipulate than I recall it being previously. And, I've never replaced the tensioner in 16 years. I'm on the site today to find a rockauto code.

All in all, it hasn't been a huge problem for me, more like an occasional annoyance. It will be hard to say whether this fixes it or not, since I'll just be waiting for it to happen again. And anyway the tensioner is likely good maintenance regardless.

When we bought this TB about 10 months ago, I replaced the water pump and all the components that were on the front of engine. Belt, tensioner....etc.

 

[movietvet]

If it is not too much of a hassle... Pull the Air Box-Inlet off of the Throttle Body and while you are looking inside of the TB for a Dark Brown, Sticky Dirt and Gunk Ring around the Plenum Venturi Opening vs. the Butterfly Plate... also give "The TOPS of The COPS" a very close inspection ...looking for signs of changes in the appearance of one or two COPs on their Little Aluminum Radiators.

If you see one that looks particularly different... begin to suspect that it has been OVERHEATING. Check out whether your Misfire Counts coincide on THAT particular Cylinder and you might be nursing along a Bad Coil that only raises its Ugly Head and Shorts to Carbon Tracing on the COP Rubber Boot whenever the A/F Leans out just a bit too much. Just an FYI... Having LEAN BTDC Conditions can ruin Coil Over Plugs in this manner... and not the other way around of having a Bad Coil as the cause of this issue.

This Stuff is Everybody's BFF when it come to Cleaning Out Throttle Bodies:

https://www.amazon.com/dp/B0002KKIDW/?tag=gmtnation-20

View attachment 110262

Also... Double Check ALL of the Grounds and Bonding Cables between the Engine Block and the Frame...AND...your closely examine the Power and Ground Battery cables too...For any signs of Cupric Oxide (Green Corrosion). They will need replacing if they are infected up inside of their Connection Eyelets. Apply a Small Dab of Dielectric Grease in between their cleaned up Contact Surfaces to prevent future Galvanic Corrosion from increasing Electrical Resistance.

Electrical Ground locations

While troubleshooting a bad ground I came across some scans of the service manual regarding electrical ground locations for our platform posted on another site. This includes both short and long wheel base, as well as both 4.2L and 5.3L. Credit goes to Wex...

gmtnation.com

I have changed the plugs, there is a video of that at you tube, and I noticed a couple of "COP' had been changed. At that point the vehicle had 70k miles on it and now has 72k miles. I have already cleaned the throttle body bore when I did the plugs. Have not noticed any misfires but I also do not drive the vehicle that much. I will attach my scanner and look for misfire history.

 

[6716]

When we bought this TB about 10 months ago, I replaced the water pump and all the components that were on the front of engine. Belt, tensioner....etc.

Fair enough.

 

[Mooseman]

Maybe try cleaning the throttle again and resetting the PCM by disconnecting the battery or pulling the fuses for 30 minutes while cleaning.