Sudden crank not start issue

Hi,

If you have no RPM signal, and based on the code, it sounds like the crankshaft position sensor is bad. I realize the codes are cam sensor codes. Check the crank sensor connection to make sure it is good and not disconnected.

See picture 1 and let me know what you find.

Joe

I see two in the picture, which one? I thought about the crankshaft sensor but didn't think it would just go out like that or it would give me a code, isn't it next to the starter or mounted to the bell housing of the transmission?

I just remembered what happened, and by the way this was a voluntary repossession and the car was starting and rattling as the owner told me. After the repo truck brought it to my house i told him i want it down the street where i store some of my cars. He already had it unloaded from the truck and in my driveway so he just drive it to where it was waiting for him maybe 1 mile or less and before he was able to reach me. 200 feet away it stalled on him.so he loaded it on the truck again and brought it to me. I didn't check it then or tried to start it. When i did today it started for 2 seconds and then shut off, then made a popping noise when i tried to start it again and would not start.

The codes are for the two cam sensors. If the RPM signal is lost, my first suspect is the crankshaft position sensor which will directly affect ignition. What I would suggest is to see if the security has it shut down and if the engine is getting ignition spark.

If a live data scanner is available, use it so confirm there is no RPM signal.

Here is a link to help with checking for ignition spark and a general link that discusses the most common causes of a crank no start condition:

https://www.2carpros.com/articles/how-to-test-an-ignition-system

https://www.2carpros.com/articles/car-cranks-but-wont-start

Let me know what you find.

Joe

thanks I am going to check that next. I just checked the fuse and was good, the relay switched it with another still no fuel pump sound and there is no 12v at the pump, so I removed the relay and primed the pump using a pin connecting it to 30/87, and the pump worked and I have 12volts. so the relay is okay I guess, and with the relay removed I checked and there is a 12v juice coming to the relay socket. The only reason I have not yet checked the crank position sensor is that the car is located at an incline and I can't yet tow it to my house.. does a bad crank shaft position sensor cuts off both spark and fuel?

You will lose both on this vehicle.

Let me know what you find.

Joe

just replaced it and started the car and same issue. Even before replacing it I would still smell gas in the engine compartment, so we know there is fuel.

Cleared all codes and tried to start with starter fluid, nothing, still getting these camshaft codes only when starting, there is rpm based on this screen correct?

You don't think a bad fuel pump? I say that because the car cut off while being driven the last time she was on. And the previous owner told me she was starting but rattling.

Are there any fuses that control ignition spark?

There isn't a fuse just for the spark. If it isn't starting with starting fluid it sounds like it isn't getting spark. Have you checked? Have you pulled plugs to see if they are wet?

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Let me know.

Joe

No have not. Thought about it. Would that cause it not to start at all? I thought they may start a bit rough but not at all?

Honestly, if there is no spark to the plugs, it will not start or even try to start. The easiest way to determine if spark is present is by using starting fluid. If it starts for a couple seconds, then we know there is a fuel related issue. If it still doesn't, the next think is to check for spark. If there is spark, then we have a timing issue or compression issue.

Let me know what you find. Please let me know if you need help or have other questions.

Take care,
Joe

What is easiest way to check for spark? Can i use a test light? What if there is no spark but there is fuel?

You can remove the plug from the engine, connect it to the coil and ground it so that you can see the electrode. Have some one crank the engine and you should get spark. Here is a link from above that explains how to check:

https://www.2carpros.com/articles/how-to-test-an-ignition-system

If there is no spark, then we will need to check the crankshaft position sensor. Also, if you have a live data scanner, see if there is an RPM signal when cranking.

Joe

I already replaced the crank position sensor. also included photos of the rpm signal, they are attached above.

Okay, have you checked for spark?

Joe

I checked it before i replaced the CPS using a test light as i had no one to assist me start the car, and there was no light. i grounded the test light and inserted the tip into a coil, no light, unless this test doesn't make sense.

I don't think that will work. Honestly, I'm surprised it wouldn't burn out the light. Most test lights are for 12v. The coil does a lot more than that.

Just checked and there is spark. I don't see the spark plugs being wet, weird, i would have thought they were. I will check fuel pressure just to make sure, but am smelling fuel. I just don't hear the fuel pump running unless i jump the relay.

What about the codes for camshaft position sensor for both banks, you think that has anything to do with why it is not starting?

just checked fuel pressure and it was around 10 with ignition on, when I cranked it and let the engine turn over few times it went up to 47 or so psi, then it started moving down within seconds, waited till it has gotten down to 42 o so. Checked voltage at fuel pump harness, with the harness removed and the multi meter connected to the largest two wires there was no volts when ignition on, only after I tried to start the car when I got 9.5v, I know it's low but because I have been trying to start it for days. But shouldn't I be getting battery voltage even with ignition on? Is it possible for the relay to be bad even though I am getting fuel pressure? problem is the engine doesn't even sputter or tries to start.

If you lost pressure when you stopped cranking, that is normal. The DME (digital motor electronics) control module will switch off the relay immediately if it no longer detects engine speed. This ensures that the fuel pump cannot continue running when the engine turned off.

Will the engine start for a couple seconds using starting fluid? If you have spark and the fuel pressure should have fired the engine, it should run unless there is no fuel injector pulse. In that case, it should still start with starting fluid.

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Fuel pressure running is around 50, so you were basically there. It should have fired.

As far as the cam sensors, we may need to take things apart to check timing. If it has spark and still won't start for a couple seconds with starting fluid, something else is happening.

Let me know.
Joe

What i meant is, the fuel pressure, which is supposed to hold for about 15 minutes or so did not, immediately after i tried to start it i turned it off then went to see the gauges, saw it at around 47, while still looking at it she started declining.
Will not start at all with starting fluid inside the throttle body.

Okay, then chances are the pump antiflow back is bad. However, that shouldn't prevent it from running. At this point, since it won't start with starting fluid and it does have spark, I would check engine compression. If there is a timing issue, it should show lower than expected compression.

Even if the cam sensors have failed, the vehicle is designed to continue running based on crankshaft sensor info.

https://www.2carpros.com/articles/how-to-test-engine-compression

Let me know.
Joe

Attached.

I can't tell what I am looking at in the video. Is that a converter? What should I pay attention to?

Removed the oil cap and tried to start it, nothing is moving on the inside.

I attached a pic of the chains. Either the one for that side has broken or the counter chain has broken. That isn't good news and explains the cam codes. If you confirm the engine is a 4.8L, I can get you the directions for replacement.

Let me know.
Joe