Cranking but not starting

[RLawman2020]

2018 xlt 3.5 no turbo. Ive tested spark plugs for fire and they are all good. It’s pumping fuel through the rail but idk if the pressure is enough bc i cant find the test port. I’ve tried starting fluid and it doesn’t try to start. Half tank of fuel, and I can hear the fuel pump priming. I parked it one afternoon and about 6 hours later went to leave and nothing. I’ve owned it for 5 years and drive it daily. Spark plugs were changed a couple months ago. Fuses are also good. Any ideas?

 

[syncceduppp]

Have you used FORScan or a scan tool to check for trouble codes?
Try testing for a plugged catalytic converter: remove one spark plug and try to start it. If that doesn't change anything put it back and try again with a plug from the other bank. If it runs during this test (will be rough), you know that you have a plugged cat that's preventing the engine from breathing out exhaust. The open spark plug hole provides a temporary alternative path for exhaust to get out.

 

[RLawman2020]

Cats were just replaced less that 1k miles ago. I have scanned it with my OBD link MX+ and cheap $40 harbor freight tool and no codes or warning lights on dash. I don’t know if this helps but I’ve noticed that after it’s sits a couple hours after messing with it, that first attempt at starting, it hits just a little but nothing after that. I tried cranking in neutral earlier thinking it might be the neutral safety switch but no luck there either. I think I found the test port for fuel pressure so that’s my next option.

 

[ProjectSHO89]

If it's not firing at all on starting fluid, it's not a fuel delivery issue.

Focus on airflow, both intake and exhaust, and on spark. If you've properly tested for the presence of spark, then that does tend to implicate airflow. Pull your air filter and inspect for foreign material or for a clogged filter.

Pulling a spark plug is not going to free up exhaust for testing. You have to pull an upstream O2 sensor in order to do that.

 

[Steve8316]

...the [fuel pressure] sensor? I’ve been looking for it for about an hour now.

Why?

Cranking but not starting.

If you hear the pump running, and starting fluid has no effect, then it's not likely a fuel pressure problem. But that still doesn't explain why you want the sensor location - seeing it won't help you diagnose the issue. The only thing that might would be monitoring its live data through its PID via a scantool or ForScan.

In any case; posting in 2 threads for 1 issue on 1 vehicle is pointless, so I'm moving this reply to your thread.

 

[RLawman2020]

If it's not firing at all on starting fluid, it's not a fuel delivery issue.

Focus on airflow, both intake and exhaust, and on spark. If you've properly tested for the presence of spark, then that does tend to implicate airflow. Pull your air filter and inspect for foreign material or for a clogged filter.

Pulling a spark plug is not going to free up exhaust for testing. You have to pull an upstream O2 sensor in order to do that.

If it's not firing at all on starting fluid, it's not a fuel delivery issue.

Focus on airflow, both intake and exhaust, and on spark. If you've properly tested for the presence of spark, then that does tend to implicate airflow. Pull your air filter and inspect for foreign material or for a clogged filter.

Pulling a spark plug is not going to free up exhaust for testing. You have to pull an upstream O2 sensor in order to do that.

I have an actual tester for spark and I’m about to do that now. So, if all 6 are firing and I know the fuel rail is full of gas bc I had it off earlier, I just need to pull and upstream O2 sensor and see if it cranks then?

 

[RLawman2020]

I have an actual tester for spark and I’m about to do that now. So, if all 6 are firing and I know the fuel rail is full of gas bc I had it off earlier, I just need to pull and upstream O2 sensor and see if it cranks then?

Update- after removing fuel rail/injectors and cleaning with some carb cleaner and testing plugs for spark it has started up but it’s rough. I have to keep on the gas or it will die. Also, while revving it some I noticed smoke coming the exhaust.

 

[peterk9]

Update- after removing fuel rail/injectors and cleaning with some carb cleaner and testing plugs for spark it has started up but it’s rough. I have to keep on the gas or it will die. Also, while revving it some I noticed smoke coming the exhaust.

Just a guess but have you ruled out a water pump issue? Is your radiator reservoir fluid up to where it should be and have you checked the oil on the dipstick to ensure it isn't contaminated (milky)?
How many miles are on it?

Peter

 

[RLawman2020]

Just a guess but have you ruled out a water pump issue? Is your radiator reservoir fluid up to where it should be and have you checked the oil on the dipstick to ensure it isn't contaminated (milky)?
How many miles are on it?

Just a guess but have you ruled out a water pump issue? Is your radiator reservoir fluid up to where it should be and have you checked the oil on the dipstick to ensure it isn't contaminated (milky)?
How many miles are on it?

Peter

Oil is good, changed it myself a couple weeks ago but I did check it just to eliminate any issues there. Coolant levels are right where they should be as well. I did a system flush about 3-4 months ago. It has 229,205. But after that initial start up, I turned it off and started searching the internet for possible fixes and let it sit for about 10-15 mins and when I started it back up it has literally ran like nothing ever happened. Idle is nice and smoooth around 500-550. No more smoke from the exhaust. Ive drive it around all afternoon since that last update and it’s like nothing ever happened. What’s really confusing is that there are no new parts. All the same components. Besides taking the fuel rail and injectors out and spraying with some carb cleaner and cleaning the plugs up, it’s all the same. I did swap the 30 amp fuel pump relay with another one that controls heated rear window and heated mirrors so idk if that did anything or not