Crank, but won't start

Gold6ix_

Member
I need to be pointed in the right direction to diagnose this crank no start issue in my trailblazer.

Possible clues, for a while I started having a longer crank before the engine would start, maybe 3 to 4 seconds, which has been going on for years so it became the norm. A few times over the past couple years I'd go to start it but it would die out because I'd let go of the key before it fired up, due to the longer crank. Other than that it has no issues, no rough idle, never stalled on me.

Now it just doesnt start at all, I can crank it until it automatically stops cranking and it wont fire up, and this happened out of no where, it wasnt a gradual thing, it went from getting in it and starting every time, to one day only cranking and not firing up. I pulled the codes, which seem to be no help but they were p0128 p0463 p0506. I hear the fuel pump energizing when I turn the key to the on position.
It's cold and snowing where I'm at, so I want to have some ideas on what to check before going out there and freezing (so I haven't checked anything yet other than fuses, codes, and listening to the fuel pump).
 

Maverick6587

Silver Supporter
Many things can start a crank no start issue. Do you have a scan tool to check for any check engine lights? Try not to unplug the battery so that any codes that are stored stay stored, until you can read them.

The slow death seems like a fuel flow issue to me. You have a 2006, which mean the fuel filter is inside the fuel pump assembly, in the fuel tank. No easy way to change the fuel filter without removing the tank.

I would start with checking the fuel pressure with a gauge at the fuel rail test port (with the green cap).

This was a good post with great suggestions for troubleshooting and searching:

EDIT: It could also be a ground that was going bad and then all of a sudden got completely corroded.
 
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Gold6ix_

Member
Yeah using my scan tool the codes that were there were p0128 p0463 p0506.

And I was going to test fuel pressure next, not sure if I wanted to buy one off amazon or rent one from the parts store. If that checks out, what's the best way to test spark? That spark tool I see ppl use that hooks on in between the spark plug and the spark plug wire wouldn't work for these trucks right? Since they have the coil packs.
 

Maverick6587

Silver Supporter
Pull a spark plug out with it still attached to the spark plug wire and lay it on metal. Or if you want to be a little safer you can get a spark plug tester that lights up. You plug it in in between the spark plug and spark plug wire.

1580929011244.png

Edit: Since you are still testing out what is wrong. I would just rent a fuel pressure tester and save your money for when you need it for parts or other troubleshooting. Buy the tools you needed after your finished, if you still have free money to spend.
 
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Gold6ix_

Member
Yeah that's the tool I was referencing, that wouldn't work on a trailblazer because they dont have the wire to plug set up they have coil packs. You know of any other ways to test spark? Is there something I can measure with a volt meter?
 

Maverick6587

Silver Supporter
I'm not 100% sure if the ignition coil bolt is part of the grounding for ignition or not, I don't think it is though. You should still be able to use that or a test light with a longer cord.

Just unplug the relay for the fuel pump, just in case it starts during your testing, since the MAF will be unplugged.
 

MRRSM

Lifetime VIP Supporter
Pull all of the Spark Plugs and examine them for the desired "Fried Chicken Brown" appearance... and having no worn or damaged Platinum Tips of the Electrodes. If necessary... Replace them all only using the ACDelco OEM version and then attempt to Start the Vehicle. Do not 'Gap' the New Spark Plugs.

Then Test the Coil On Plugs portion of the Ignition Circuit, by using the Hantek Model 1008C (8) Channel Oscilloscope, a 20:1 Attenuator, Electric Circuit Probes with BNC Connectors along with either a Portable Tablet or Laptop Computer for the Hantek Diagnostic Software. The Oscilloscope makes it possible to Analyze the Performance of the Ignition Systems using the Coil On Plug Ignition Design like those of the GM 4,5 & 6 Cylinder Atlas Engines.

As you previously mentioned, unlike other Ignition Systems with External Wires that allow for the use of Noid Lights and Spark Gap Analyzers... doing so is difficult if not impossible with COP Systems.

This Hantek 1008C Kit is offered on Amazon for Under $100.00. The 20:1 BNC Attenuator is not necessary for this particular Ignition Pattern Analysis... but it WILL be necessary for the use of the PWM 5 Volt Channel and is sold separately for around $10.00:


HANTEK1008CKIT.jpg

The idea here is to Back Probe each individual COP and observe the Laptop Screen for the Graphical Wave Form showing the Build Up of the Low Voltage on the Primary side of the Coil... followed immediately by the Transistor Shutting Down that induces Current Flow in the High Voltage Secondary Coil.

The best way to observe this phenomena On Screen is to have Channel (1) registering the 5 Volt Square Wave PWM (Pulse Width Modulation) Signal adjacent to and aligned with Channel (2) observing the Spark Performance Activity.

The Computer Screen displays these actions in a Graphical Form that allows you examine the Health of the Coil and the Strength (or lack thereof) just as the Spark is attempting to 'Jump The Gap' inside of each Cylinder while under the serious stress of Compression at around 10 Atmospheres resisting that Electrical "Jump".

This Video shows HOW all of these activities get done:


For possible EFI problems in your Engine... THIS Video shows the Set Up and Use of this very same equipment:

 
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Mooseman

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Gold6ix_

Member
I wasnt notified of any new responses to this thread, I'm just now seeing them.

It's still snowing where I live so haven't done much other than spray some starting fluid into the air intake, once I did that the car tried to start, it stuttered but couldn't fully fire up as if it was going off of the starting fluid alone and had no fuel. So I'm going to rent a tool this week and go out and check the fuel pressure if I get a day the sun is out and its a little warm.

With the car trying to start, is that a good confirmation that this is fuel related and the spark side of things are probably ok?
 

Maverick6587

Silver Supporter
With the car trying to start, is that a good confirmation that this is fuel related and the spark side of things are probably ok?
If you just squirted starting fluid once without a continuous flow, I would assume that it is your fuel flow/fuel pump issue.

Remove your gas cap and then turn your key to the on position. Then have someone else listen at the gas cap fill port, or you will have to quickly do that yourself. The fuel pump only turns on for 2 seconds or so to prime the system.

Check relay 41 on the fuse box under your hood. Make sure that it is getting power. Check ALL other fuses while you are there.

There are 4 grounding bolts on the left side of the engine in a square pattern. Unbolt all of them and clean them and where they bolt to the engine. Even if they look clean they still might not be getting a good ground (it happened to me).

The second grounding point for the fuel pump is on the outside of the frame underneath the driver's side rear door. Make sure to remove and clean that bolt and frame where it bolts to.

If you still do not hear the fuel pump prime after checking for power and grounds away from the fuel pump. You'll have to remove the fuel tank itself for further testing. At this point you might as well order a fuel pump while you have the tank removed. If you can fix it with the tank removed, then just return the pump.

Just don't open the box as most parts stores won't let you return electronic parts if the box has been opened. Amazon is your friend here, they don't care if it's been opened. Just only buy ACDelco or Bosch fuel pumps. I went through two Delphi fuel pumps on my 06', so I'm hesitant to recommend Delphi for fuel pumps.
 
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Gold6ix_

Member
If you just squirted starting fluid once without a continuous flow, I would assume that it is your fuel flow/fuel pump issue.

Remove your gas cap and then turn your key to the on position. Then have someone else listen at the gas cap fill port, or you will have to quickly do that yourself. The fuel pump only turns on for 2 seconds or so to prime the system.

Check relay 41 on the fuse box under your hood. Make sure that it is getting power. Check ALL other fuses while you are there.

There are 4 grounding bolts on the left side of the engine in a square pattern. Unbolt all of them and clean them and where they bolt to the engine. Even if they look clean they still might not be getting a good ground (it happened to me).

The second grounding point for the fuel pump is on the outside of the frame underneath the driver's side rear door. Make sure to remove and clean that bolt and frame where it bolts to.

If you still do not hear the fuel pump prime after checking for power and grounds away from the fuel pump. You'll have to remove the fuel tank itself for further testing. At this point you might as well order a fuel pump while you have the tank removed. If you can fix it with the tank removed, then just return the pump.

Just don't open the box as most parts stores won't let you return electronic parts if the box has been opened. Amazon is your friend here, they don't care if it's been opened. Just only buy ACDelco or Bosch fuel pumps. I went through two Delphi fuel pumps on my 06', so I'm hesitant to recommend Delphi for fuel pumps.

Yes, I was by myself so only sprayed some in the intake and went around to start it and it tried to, so not a continuous flow.

I ordered a test light with the LCD screen that shows voltage so I can better check the fuses grounds and plugs etc to see if they check out. Itll be here today so I'm going to check all that out today hopefully.
 

Maverick6587

Silver Supporter
Did you get a chance to listen for the fuel pump prime?
 

Maverick6587

Silver Supporter
I would rent a fuel pressure sensor then if you can hear the pump energize. You can rent them from most auto parts stores. If you are getting pressure then you may have a problem with your fuel rail/injectors.
 

MRRSM

Lifetime VIP Supporter
Without knowing whether or not you live in a rural area of Colorado that presently has any rodent population problems... since the Little Bastards teeth grow constantly during their entire lifetimes...they can get attracted to a Warm Engine Bay... climb up the tires and frame sections and finally nest in and around the Engine Nacelle. If you examine your engine quarters and can see signs of twigs, nest building and rodent droppings... you can be certain they will have been gnawing incessantly on the insulation and wiring harnessing under there. So this might be another place to 'look for trouble'.
 
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Gold6ix_

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I just got on here to give an update, I went into the engine bay to test the fuses and I noticed a bunch of grass up against the driver side fire wall, so I dig it out. Which was suspicious, I dont know if that was birds or what. So then I inspect the engine bay some more and behind the engine cover up against the firewall theres some harness that's been chewed through completely, only one wire is left intact. I'll attach pictures, maybe one of you can tell me what it controls.
 
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Gold6ix_

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Without knowing whether or not you live in a rural area of Colorado that presently has any rodent population problems... since the Little Bastards teeth grow constantly during their entire lifetimes...they can get attracted to a Warm Engine Bay... climb up the tires and frame sections and finally nest in and around the Engine Nacelle. If you examine your engine quarters and can see signs of twigs, nest building and rodent droppings... you can be certain they will have been gnawing incessantly on the insulation and wiring harnessing under there. So this might be another place to 'look for trouble'.
I think you accurately guessed exactly what happened. But I can't forsure say if this just happened after the car issues or if it was present the whole time. I only now noticed it.
 

Maverick6587

Silver Supporter
Don't forget to unplug your battery ground while you're working on repairing those wires. Nice find btw!
 

Maverick6587

Silver Supporter
Honestly it could be both fuel and spark. I'd have to look through the diagram. Give me a few and I'll check back with my research finds.
 

MRRSM

Lifetime VIP Supporter
Please... Take some additional precautions to avoid becoming infected with the Deadly Hantavirus carried by Rats and Mice and deposited in Rodent Urine and Feces. Once the liquid in those waste materials dries out and desiccates... the particles of dust carrying the Virus can be inhaled and thus the aerosolized infection can enter the lungs. The CDC Hantavirus Reported Infections Cases for 2018 were the highest in California ...and your State of Colorado:

HANTAVIRUSDISTRIBUTIONUSA.png
This is a Virus that is carried by the Deer Mouse all over North America and is similar in its infectious nature and etiology to those of Lassa Fever, Marburg and Ebola Viruses that can cause sudden Uncontrollable Edema in the Lungs leading to suffocation and-or Hemorrhaging and Death in 36% of the North American Cases. This "flavor" variant goes by the expression SNV or the "Sin Nombre Virus" ...AKA "No Name Virus".

These viruses are all cousins and are equally deadly. So Please.... Mask and Glove Up BEFORE you remove those nesting sites and materials into Sealed Plastic Baggies and also the wipes you will need to use and discard after contact with all of those potentially infected areas. Use either some Calcium Hypo-Chlorite mixed in Water or Straight Chlorine Bleach.

These two WIKIs are worth reading concerning Hemorrhagic Fever being caused by these Damned Infected Vermin:


 
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Maverick6587

Silver Supporter
Looks like they are all for the injectors. Green w/black, Lt Blue w/black, Yellow w/black, Pink w/black, Black w/white, and Black

1581525623447.png
 
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Gold6ix_

Member
Please... Take some additional precautions to avoid becoming infected with the Deadly Hanta Virus carried in Rodent Urine. Once the liquid urine dries and desiccates... the particles of dust carrying the Virus can be inhaled and thus the infection can enter the lungs. This is a 'Thread Virus' has occurred in your area of the country and is similar in its infectious nature and etiology to the Marburg Germany Virus and to Ebola.

These viruses are all cousins and are equally deadly. So Please.... Mask and Glove Up BEFORE you remove those nesting sites and materials into Sealed Plastic Baggies and also the wipes you will need to use and discard after contact with all of those potentially infected areas. Use either some Calcium Hypo-Chlorite mixed in Water or Straight Chlorine Bleach.
Wow thanks for the heads up, I had no idea. I had gloves on while removing the nest, but not when tampering with the wires. I'll be sure to take extra precaution when I head back out there.
 
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Gold6ix_

Member
Looks like they are all for the injectors. Green w/black, Lt Blue w/black, Yellow w/black, Pink w/black, Black w/white, and Black

View attachment 93131
Ok thanks. I figured it was by how all of a sudden the car stopped working when it was fine before, without any real signs. And I tried to Google fuel injector harness for 2006 trailblazer, just to replace the hole wiring harness but couldn't find the part. So I'll have to see how much wire is left on the connector to see how easy it will be to repair what's there.
 

Maverick6587

Silver Supporter
Here's one on ebay.

Wire Injector Harness L6 4.2l Rainer Trailblazer Envoy Ascender SAAB 9-7x

Edit: You could just grab one from your local junkyard as well. Should be a quick pull. You should grab the connector to the MAP sensor as well. I think that's what that orange wire connects to. Maybe it's all part of the same harness, I just don't see it on that ebay link though.

Most junkyards charge you per ft for wiring harness. I think mine charges like $0.40/ft so, it might only cost you a few dollars to get it from the junkyard.
 
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Gold6ix_

Member
Here's one on ebay.

Wire Injector Harness L6 4.2l Rainer Trailblazer Envoy Ascender SAAB 9-7x

Edit: You could just grab one from your local junkyard as well. Should be a quick pull. You should grab the connector to the MAP sensor as well. I think that's what that orange wire connects to. Maybe it's all part of the same harness, I just don't see it on that ebay link though.

Most junkyards charge you per ft for wiring harness. I think mine charges like $0.40/ft so, it might only cost you a few dollars to get it from the junkyard.
I don't mind paying 25 bucks, and the seller has 99 percent feed back. When I get back home I'm going to disconnect that harness and take it off to make sure it is connected to the injectors and if so I'll go ahead and make that purchase. If all is well then that should be the fix, which is better than dropping the fuel tank and replacing a fuel pump. I even checked the Schrader valve, pressed it and gas sprayed out, although I didnt check the exact psi with the tool, I know it has pressure. So hopefully this will be the fix.
 

MRRSM

Lifetime VIP Supporter
FWIW... Widen your Gaze under the Hood and while using a very Bright Flashlight... Give things down there a very thorough going over. Be suspicious of ANYTHING those 'Filthy, Furry Bags of Disease' might have been Chewing on... or into.
 
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Gold6ix_

Member
I was already thinking to do that. Nothing in that immediate area looked like it was bothered with other than that. But it snowed again, so when I get some more sun out I was going to do a thorough check.
 

christo829

Well-Known Member
Not trying to hijack, but I feel your pain... Last Thursday, the TB drove home fine, wipers worked, all was good. Friday morning it was pouring, and I had no front wipers. Popped open the hood, didn't see anything wrong, fuses checked good, but by then the rain had settled down, so I drove to work.

Saturday, I got ready to run some stuff over to the thrift store and get a replacement wiper motor to have on hand just in case testing proved it dead. Truck started, but half the instrument panel was out, and the shift interlock wasn't working, so I couldn't get out of park.

*This* time, looking under the hood found me the attached images...

Hood liner:
IMG_20200208_135901440.jpg

Stuffed resonator:
IMG_20200208_140623372_HDR.jpg

Wiring harness between firewall and under hood fuse block:
IMG_20200208_140636317_HDR.jpg

HVAC low pressure switch harness:
IMG_20200208_140734498_HDR.jpg


Spent that weekend soldering patch wiring in just to get things working. 19 solder joints later, the truck is back to driveable, but I may have missed a break in a 4wd encoder circuit, and I think I have the defog circuit done incorrectly (thanks, GM, for using the same green and black wire twice in the same bundle, close together, and thanks rodent, for managing to take a chunk out of *both* so I couldn't just match them up). I thought I had them mapped out correctly, but I was obviously wrong.

I've since put rodent repellent and peppermint soaked cloths in perforated bags in that space
between the fender and the firewall, and have been propping the hood slightly open so it's no longer an enclosed, secure place for the critters to hide.

The relevant part of this is that it only took them one night to do the majority of the damage, wipers notwithstanding.

Good Luck!

Chris
 
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Gold6ix_

Member
Not trying to hijack, but I feel your pain... Last Thursday, the TB drove home fine, wipers worked, all was good. Friday morning it was pouring, and I had no front wipers. Popped open the hood, didn't see anything wrong, fuses checked good, but by then the rain had settled down, so I drove to work.

Saturday, I got ready to run some stuff over to the thrift store and get a replacement wiper motor to have on hand just in case testing proved it dead. Truck started, but half the instrument panel was out, and the shift interlock wasn't working, so I couldn't get out of park.

*This* time, looking under the hood found me the attached images...

Hood liner:
View attachment 93143

Stuffed resonator:
View attachment 93144

Wiring harness between firewall and under hood fuse block:
View attachment 93145

HVAC low pressure switch harness:
View attachment 93146


Spent that weekend soldering patch wiring in just to get things working. 19 solder joints later, the truck is back to driveable, but I may have missed a break in a 4wd encoder circuit, and I think I have the defog circuit done incorrectly (thanks, GM, for using the same green and black wire twice in the same bundle, close together, and thanks rodent, for managing to take a chunk out of *both* so I couldn't just match them up). I thought I had them mapped out correctly, but I was obviously wrong.

I've since put rodent repellent and peppermint soaked cloths in perforated bags in that space
between the fender and the firewall, and have been propping the hood slightly open so it's no longer an enclosed, secure place for the critters to hide.

The relevant part of this is that it only took them one night to do the majority of the damage, wipers notwithstanding.

Good Luck!

Chris
So the rodents pretty much went to work initially and disabled your wipers, then after another night they went to town again and did the rest of that damage? I would've been sick to pop my hood and see all that.

But hopefully all they did was chew through the wiring harness shown in my picture, I'll know forsure soon though. I learned my lesson, I live in an apartment complex and I have multiple cars, so I parked the trailblazer in a spot next to an open grassy area for about 3 to 4 days when this happened while driving the other. From now on I'll stay parked in between cars and try to not let my cars sit in the same spot for too long.
 

christo829

Well-Known Member
Most of the damage they did to that wiring harness was done to the class 2 data bus wires, except
for one heavier gauge white one. I think the first night they'd damaged others, but they hadn't ripped out the hood insulation, and I didn't look down in that space by the fire wall, just looked at the fuse boxes. Then the rain stopped, so I figured I'd just get on to work and do some real diagnostics later. So yeah, my bet is that they'd already done some damage, and they came back overnight to try eating the rest of it.

Hope you can track down a replacement harness you can swap in to yours!

Cheers-

Chris
 

MRRSM

Lifetime VIP Supporter
Not trying to sound TOO much like an Alarmist here... But for the sake of BOTH of you, It might be a good idea to know that since 1993 up until 2017... The CDC recorded a National Hantavirus Surveillance and uncovered 728 Reported Cases of this Hantavirus disease. And without knowing where Chris lives... please review the entire history of which states have the greatest clusters of these confirmed infections at this Link where you can view, (Year By Year), where and how many illnesses occurred.

This Data set is large enough to be taken seriously for being a potential serious health risk, given that both of your vehicles bear the same confined conditions and artifacts of Rodents present in numbers living in the engine compartments under the perfect conditions for transmitting infection. In 1993 over 50% of those infected ...perished:

Special Attention:

Please look closely at that Map below If you live anywhere West of the Mississippi River and have any "Cranks... No Start" issues. Making an Under Hood Search for any "Chewed Wires" on the Harnesses and Connectors First might speed things up towards solving the problem.


Distribution of Hantavirus Cases in the USA 1993-2017:

HANTVIRUSDISTRIBUTION.jpg

https://www.cdc.gov/hantavirus/surveillance/reporting-state.html
https://www.cdc.gov/hantavirus/surveillance/in

Over the lifetime of this study... here is how they all Map Out... Noting that New Mexico was #1 and Colorado was #2 for the greatest numbers of cases. Being aware of this should guide your actions as to whether or not setting out Rodent Traps, Baits and Poisons would not be too far of a reach to consider doing.

It follows on that you BOTH should be very careful to Mask yourselves, Wear Encompassing Eye Protection as the Airborne Hantavirus on Dust Particles can also Infect through the Wet Corneal Surfaces of the Eyes. And last of course is to wear Medical Gloves while wiping all contact surfaces down with a Rag Soaked in Bleach. Hopefully these precautions will serve to prevent anything untoward from happening while you both hover under the closed-hooded confines of each vehicle... conducting the necessary Electrical Harness Repairs:

I promise... After this... I'll say no more about the matter...
 
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Maverick6587

Silver Supporter
I just added rodent repellent to my shopping cart!!! @christo829 Did you just use generic peppermint essential oil? I'm thinking I'll mix the peppermint oil in water and use a spray bottle to really freshen up that engine bay!

Thanks to you two and @MRRSM for even suggesting looking for rodent chewed wires. Asking about chewed wires, is now added to my Q&A arsenal for engine/car diagnostics!
 

christo829

Well-Known Member
@Maverick6587 Yeah, just got a bottle of essential oil. I can't tell if the peppermint oil or leaving the hood part way open is being the biggest deterrent, and at this stage I'm not really willing to properly test. :wink:

@MRRSM I'm in Virginia. One reported case of Hantavirus as of 2017, but I also help out with archaeology digs in the region, and the mice *love* the covered test units, so it's at least on our radar as something to be aware of and take precautions.
 
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Gold6ix_

Member
Yesterday morning when I checked, its actually the wiring harness that goes to the ignition coils. It looked a little different from the picture on that Ebay listing. So I've been scouring the internet for one, and if I can't find one I may have to hit up a junkyard.
 

MRRSM

Lifetime VIP Supporter
If it comes down to a demand to create your own One-4-One Color Coded OEM Quality Wire Harness to R&R for the presently 'Chewed and Spewed' COP and/or EFI Harnesses... Using the right AWG and Automotive Quality Wire(s) will be important for demanding High Temperature and Chemical Resistance as well having a wire bundle with Locked Insulation that can neither Creep nor Migrate along the lengths of the individual Wires.

THIS BNTECHGO Wire Bundle has a selection of (10) Unique Colors @ 5' Lengths and is 18 AWG (Silicone Insulation over Tinned Copper). This Wire meets the requisite standards for safe use on Engines, Transmissions and for Interior use for Automotive Applications:


If you know how to Solder in Automotive Applications already... Great. If not... PM me and I'll provide some additional information about Prep Steps, Tools, Thin Solid Silver Rosin Core Solder, Using the right kind of Heat Shrink, etc.... and other information on how it can best be done. @christo829 has fresh experience now, too ...so ask him for information on how his repairs are being done. As ever... For Jobs like Engine Harness making... Youtube can be your Friend.
 

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