Car won't start!
Thread Starter
TECH Apprentice
Joined: Oct 2007
Posts: 311
Likes: 4
Car won't start! I have an issue with my 2007 cts-v. This car won't start and I'm leaning towards the battery. Six months ago, I needed a jump start, since than I've done some light mods, and now it's ready to start but won't turn over all the way. I'm guessing its low on CCA even when fully charged. The battery is out of its 36 months warranty window and that is why I'm leaning towards the battery. The Mods are small cam and fast 102 intake. What I'd like to figure out is if there is a schematic for the LS2 coil pack, and what resistance would you see using a DMM when measuring the contact points. Can you guys help?
Staging Lane
Joined: Nov 2023
Posts: 63
Likes: 13
From: Columbia, SC
Well, Im a newb here, and learning how to tune, but this is far from a tuning issue, more of a mechanical issue.
When you say "wont turn over all the way" do you mean the engine wont even turn one revolution? If so change the battery, first step. A full charge doesn't mean much if the battery cant handle load. It may well have 12v but under load the capacity of the battery to provide power may not be sufficient.
"wont turn over all the way" meaning the engine cranks like normal but wont catch and fire? If so, spark, fuel, air. What's missing?
I suspect by what you are saying in that you needed a jump, and then did mods, which means the car was off the road, you're going to need a battery. Take it out and bring it to Advance, autozone, whomever and have it LOAD TESTED.
When you say "wont turn over all the way" do you mean the engine wont even turn one revolution? If so change the battery, first step. A full charge doesn't mean much if the battery cant handle load. It may well have 12v but under load the capacity of the battery to provide power may not be sufficient.
"wont turn over all the way" meaning the engine cranks like normal but wont catch and fire? If so, spark, fuel, air. What's missing?
I suspect by what you are saying in that you needed a jump, and then did mods, which means the car was off the road, you're going to need a battery. Take it out and bring it to Advance, autozone, whomever and have it LOAD TESTED.
TECH Fanatic
Joined: Jul 2022
Posts: 1,032
Likes: 389
From: Alaska
Been sitting a while ?
Remove battery, and put on FAST charge. ( at least 30 or 40 amps)
Remove the spark plugs.
Rotate the engine, a full revolution. Note whether any coolant or fuel is expelled.
Replace spark plugs.
Install charged battery.
Attempt start.
Report results.
Remove battery, and put on FAST charge. ( at least 30 or 40 amps)
Remove the spark plugs.
Rotate the engine, a full revolution. Note whether any coolant or fuel is expelled.
Replace spark plugs.
Install charged battery.
Attempt start.
Report results.
Thread Starter
TECH Apprentice
Joined: Oct 2007
Posts: 311
Likes: 4
Well, Im a newb here, and learning how to tune, but this is far from a tuning issue, more of a mechanical issue.
When you say "wont turn over all the way" do you mean the engine wont even turn one revolution? If so change the battery, first step. A full charge doesn't mean much if the battery cant handle load. It may well have 12v but under load the capacity of the battery to provide power may not be sufficient.
"wont turn over all the way" meaning the engine cranks like normal but wont catch and fire? If so, spark, fuel, air. What's missing?
I suspect by what you are saying in that you needed a jump, and then did mods, which means the car was off the road, you're going to need a battery. Take it out and bring it to Advance, autozone, whomever and have it LOAD TESTED.
When you say "wont turn over all the way" do you mean the engine wont even turn one revolution? If so change the battery, first step. A full charge doesn't mean much if the battery cant handle load. It may well have 12v but under load the capacity of the battery to provide power may not be sufficient.
"wont turn over all the way" meaning the engine cranks like normal but wont catch and fire? If so, spark, fuel, air. What's missing?
I suspect by what you are saying in that you needed a jump, and then did mods, which means the car was off the road, you're going to need a battery. Take it out and bring it to Advance, autozone, whomever and have it LOAD TESTED.
Thread Starter
TECH Apprentice
Joined: Oct 2007
Posts: 311
Likes: 4
Been sitting a while ?
Remove battery, and put on FAST charge. ( at least 30 or 40 amps)
Remove the spark plugs.
Rotate the engine, a full revolution. Note whether any coolant or fuel is expelled.
Replace spark plugs.
Install charged battery.
Attempt start.
Report results.
Remove battery, and put on FAST charge. ( at least 30 or 40 amps)
Remove the spark plugs.
Rotate the engine, a full revolution. Note whether any coolant or fuel is expelled.
Replace spark plugs.
Install charged battery.
Attempt start.
Report results.
TECH Fanatic
Joined: Jul 2022
Posts: 1,032
Likes: 389
From: Alaska
You did exactly NONE of what I recommended.
FULLY CHARGE and load test the battery.
If you are unable to do this, take it to an auto electric shop, and have THEM Charge, and then Load test your battery.
Staging Lane
Joined: Nov 2023
Posts: 63
Likes: 13
From: Columbia, SC
When I say "won't turn all the way" it turns but won't start. I can hear the starter work but it's like it doesn't have enough to start it. There is fuel in the rails, sparks are good, coil packs I'm questioning. Everything was working 6 months ago so I'm assuming there good, but I'd like to check with a DMM. By checking the coil packs i can rule them out and shoot for the battery. Plus, the battery is expensive, so I'll have to wait a bit.
This is still confusing, either the starter turns the motor over continuously or it doesn't. Yes a battery may be expensive, but coils are as well. Take the battery to advance, auto zone, oreillys and have it LOAD tested. "I can hear the starter work but it's like it doesn't have enough to start it" if the engine is cranking properly then you need to determine if it's missing spark, air, or fuel.
Just because there is fuel in the rail doesn't mean the injectors are pulsing. Do you have a spark tester? They are fairly inexpensive and you put it inline between coils wires and plugs. That will tell if there is at least a little spark.
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Thread Starter
TECH Apprentice
Joined: Oct 2007
Posts: 311
Likes: 4
So the battery was fully charged at 12.5V got it load tested, guy at Orielly's said it was good. Placed back in and got the same results no start.
Recharged it to 12.5 V (that was the highest it would charge) got a second opinion from a different Oreily's and they load tested it and said weak battery. After talking to him about batteries he said they should 13.5 V when measuring. He demonstrated on a new AGM and non AGM both batteries read 13.5 V.
Placed my battery back in after a charge and I got the same results.
So, I looked at the spark plugs, and they were a bit dirty (like fresh dirty opposed to dirt that's been there for a while), measured the resistance on all spark plugs and they read 4.5 to 4.6 K ohms and shorts from threaded area to the ground electrode. Measured the spark plug wire and resistance was the same on everyone plus or minus a few ohms. Nothing abnormal came out of the engine when I rotated. It smelled like fuel a little bit.
This is still confusing, either the starter turns the motor over continuously or it doesn't. Yes a battery may be expensive, but coils are as well. Take the battery to advance, auto zone, oreillys and have it LOAD tested. "I can hear the starter work but it's like it doesn't have enough to start it" if the engine is cranking properly then you need to determine if it's missing spark, air, or fuel.
Just because there is fuel in the rail doesn't mean the injectors are pulsing. Do you have a spark tester? They are fairly inexpensive and you put it inline between coils wires and plugs. That will tell if there is at least a little spark.
Just because there is fuel in the rail doesn't mean the injectors are pulsing. Do you have a spark tester? They are fairly inexpensive and you put it inline between coils wires and plugs. That will tell if there is at least a little spark.
Last edited by oxblood!z28; Jan 15, 2024 at 06:49 PM.
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Make sure you don't have a hydrolocked engine by removing the spark pugs and see if it will turn over. If your battery really is okay then you must have a bad connection somewhere. Before you do this though you will need to pull the fuse for the ignition.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
For those of you who can't/didn't watch his video, let me give an executive summary:
The engine cranks just fine, the battery is fine and it is obviously not hydrolocked. His video even shows a sparkplug light flashing, so he has spark.
@oxblood!z28 - Your last post was very vague about what "same result" means. Your video was helpful as it shows good cranking and spark.
I would now suggest spraying some starter fluid into the throttle body as you are trying to start it. Assuming it then runs for as long as the starter fluid lasts, you have a fueling issue. You say you have 58 lbs fuel pressure on the rail. If all true so far, that leaves the injectors, more specifically why the ECM isn't firing them. I don't know your specific car, but I would check if there is a fuse for just the injectors, or have you checked for +12V in the injector wiring.
Also don't know if perhaps your ECM won't fire the injectors if your key is not recognized.
In short, try starter fluid and let us know the result.
The engine cranks just fine, the battery is fine and it is obviously not hydrolocked. His video even shows a sparkplug light flashing, so he has spark.
@oxblood!z28 - Your last post was very vague about what "same result" means. Your video was helpful as it shows good cranking and spark.
I would now suggest spraying some starter fluid into the throttle body as you are trying to start it. Assuming it then runs for as long as the starter fluid lasts, you have a fueling issue. You say you have 58 lbs fuel pressure on the rail. If all true so far, that leaves the injectors, more specifically why the ECM isn't firing them. I don't know your specific car, but I would check if there is a fuse for just the injectors, or have you checked for +12V in the injector wiring.
Also don't know if perhaps your ECM won't fire the injectors if your key is not recognized.
In short, try starter fluid and let us know the result.
Thread Starter
TECH Apprentice
Joined: Oct 2007
Posts: 311
Likes: 4
For those of you who can't/didn't watch his video, let me give an executive summary:
The engine cranks just fine, the battery is fine and it is obviously not hydrolocked. His video even shows a sparkplug light flashing, so he has spark.
@oxblood!z28 - Your last post was very vague about what "same result" means. Your video was helpful as it shows good cranking and spark.
I would now suggest spraying some starter fluid into the throttle body as you are trying to start it. Assuming it then runs for as long as the starter fluid lasts, you have a fueling issue. You say you have 58 lbs fuel pressure on the rail. If all true so far, that leaves the injectors, more specifically why the ECM isn't firing them. I don't know your specific car, but I would check if there is a fuse for just the injectors, or have you checked for +12V in the injector wiring.
Also don't know if perhaps your ECM won't fire the injectors if your key is not recognized.
In short, try starter fluid and let us know the result.
The engine cranks just fine, the battery is fine and it is obviously not hydrolocked. His video even shows a sparkplug light flashing, so he has spark.
@oxblood!z28 - Your last post was very vague about what "same result" means. Your video was helpful as it shows good cranking and spark.
I would now suggest spraying some starter fluid into the throttle body as you are trying to start it. Assuming it then runs for as long as the starter fluid lasts, you have a fueling issue. You say you have 58 lbs fuel pressure on the rail. If all true so far, that leaves the injectors, more specifically why the ECM isn't firing them. I don't know your specific car, but I would check if there is a fuse for just the injectors, or have you checked for +12V in the injector wiring.
Also don't know if perhaps your ECM won't fire the injectors if your key is not recognized.
In short, try starter fluid and let us know the result.
When I mentioned fuel pressure, I was referring to fuel in the rail (I guess I wasn't very clear). When I checked the fuel pressure, I pressed the Shrader valve and fuel came shooting out. I know that doesn't indicate accurate fuel pressure, but it tells me fuel is there. I will be using a fuel gauge soon to get an actual measurement. Thanks for the advice mrvedit, I'll keep you guys posted.
Thanks
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
The car should start even with a dramatically wrong tune. It just won't run well or might not even idle for long. But definitely fire and try to start.
They say that for an engine to run you need "Compression, spark and fuel", but you also need reasonably correct valve timing. Even if the camshaft were way off, e.g. a valve was open when the spark plug fired, you would something fire.
You clearly have compression and spark; lets assume the camshaft is connected. It should then fire with starting fluid.
They say that for an engine to run you need "Compression, spark and fuel", but you also need reasonably correct valve timing. Even if the camshaft were way off, e.g. a valve was open when the spark plug fired, you would something fire.
You clearly have compression and spark; lets assume the camshaft is connected. It should then fire with starting fluid.
Thread Starter
TECH Apprentice
Joined: Oct 2007
Posts: 311
Likes: 4
So, it started with engine starter fluid. I gave it another try and feathered the pedal. It shows that the fuel injectors are working. I think my problem may be a timing issue or tune problem not sure yet. Here are a couple videos. I got lucky renting a Noid device at another Oreily's.
Video 2 shows the Noid flashing, video 3 is starter fluid assisting ignition, and video 4 is me feathering the pedal.
Video 2 shows the Noid flashing, video 3 is starter fluid assisting ignition, and video 4 is me feathering the pedal.
Last edited by oxblood!z28; Jan 22, 2024 at 09:57 PM.
Staging Lane
Joined: Nov 2023
Posts: 63
Likes: 13
From: Columbia, SC
So ill jump in here, I think if it runs with starting fluid, then valve train isn't an issue, clearly the valves are opening and closing, under that premise, even if valve timing were off and all other systems worked then you should get something, it would run like a bag of smashed apples but should "run". So, clogged injectors/ not enough fuel pressure is where I am leaning. noid light shows firing, and even if they were firing off time, engine should still "run" Do you have a helper continuously spraying starting fluid in while you feathered the pedal? If not then im thinking low pressure. (not enough to start engine but enough to run it if thats a thing) if so then I would start with replacing injectors, ( as long as fuel pressure checks out)
Thread Starter
TECH Apprentice
Joined: Oct 2007
Posts: 311
Likes: 4
So ill jump in here, I think if it runs with starting fluid, then valve train isn't an issue, clearly the valves are opening and closing, under that premise, even if valve timing were off and all other systems worked then you should get something, it would run like a bag of smashed apples but should "run". So, clogged injectors/ not enough fuel pressure is where I am leaning. noid light shows firing, and even if they were firing off time, engine should still "run" Do you have a helper continuously spraying starting fluid in while you feathered the pedal? If not then im thinking low pressure. (not enough to start engine but enough to run it if thats a thing) if so then I would start with replacing injectors, ( as long as fuel pressure checks out)