Engine stalls when warm

Good afternoon,

There is a coolant sensor that sends the information to the ECM for fuel mapping. If it is not sending the correct signal, the ECM will send a fuel map that cause it to stall.

https://www.2carpros.com/articles/engine-stalls

I would also check the fuel pressure to be sure there is sufficient fuel to the injectors.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Roy

this truck starts and idles fine until 165 temperature. once warm it's is good for the day. no problems. once warm the truck runs fine all day.if it was low fuel pressure it would stall all the time .it also does not have a coolant temp sensor

Also check the mass airflow sensor for contaminants, I've had several come in on the hook like this and had a bug stuck to the mass airflow sensor. Also bad intake gaskets can do that, just pour a little water over the intake and listen for the slurping sound, this only works when the leak is huge though.

I have cleaned the throttle body and MAF. no change. no intake leak. it runs fine until 165 degrees. temperature sensor seems okay, it showed 46 today and 51 on the dash. once the truck has worked it runs fine and will not stall again. vapor purge valve doesn't seem to open until it is warmed up and only shows 48 percent.

Hello,

I agree with ASEMASTER6371. This sounds like the engine coolant temperature sensor needs to be replaced. What happens is when it gets warm it can short out/false readings. Lets put it on a scanner to confirm the readings. This guide will help:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Here is the coolant sensor location so you can check it out. Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

that is for a diesel. I have a 6.2 has engine.

after my engine is warm it runs fine all day. I can go back out and drive it 5 hours later and no problems. it happens after it sits over night.

yes, it looks normal. when it shows 165 it stalls 170 it's fine. canister purge is not opening until 170 and inky 48 percent.

What is normal?

When it hits the temperature, does it drop out and come back?

Roy

When it hits 165 the idle will jump up and down and stall. it will restart and do the same thing. sometimes it will do it a third time then be fine.

I'll have to recheck tomorrow. it's warmed up now . I don't know if it shows voltage just temperature. It's crazy I am going to change all the o2 sensors and MAF this week. Okay, today I ran it and it stalled at 165. I started it again and the idle was jerky and idled really rough. It stalled again. Restarted again but smooth and stalled. Fourth start it stayed running like nothing was wrong. This time I got a pending code p0365. No check engine light. This time I saw purge valve opening earlier then I have seen before.

Okay, keep me updated.

I am looking for something specific that relates to voltage and fuel mapping causing your issue. Okay, I doubt that will have any effect on it. That is why I want to see readings when it drops out. Okay, disconnect the purge valve to see if it stops.

I still need all the data that I requested.

Roy

it runs fine now. I did not see a voltage area on my scanner. on the last restart it ran fine like nothing is wrong. I did a frame recording of it running what do you need for me to send you? thanks

P0365 Camshaft Position Sensor B Circuit Bank 1 - This may cause the issue. Have you replaced the coolant sensor? Here is the camshaft sensor location so you can check it out and replace it if needed. Check out the diagrams (below). Please let us know what you find.

I don't believe I have a coolant sensor. I have a cht sensor under the intake. I just realized there were 4 pending codes a p0369, p0390 and a p0394.

neither of the pictures you sent me are my engine.

Okay, I attached the coolant sensor locations for you. There are 2 on your engine. I attached locations of both.

I need the information from the scan tool when the issue happens, not when it is running good.'

The 369 is for the cam sensor circuit malfunction.

The 390 is for the other cam sensor.

The 394 is another cam circuit code.

These are circuit codes and the wiring and voltages need to be checked to the sensors.

Roy

That is not my engine. I have a 6.2. I just restarted it all codes are gone. I did notice something with my o2 sensor voltage I will send a video. ma voltage is jumping from low to really high.

All that information is for the 6.2 engine.

Give me your complete VIN number.

Roy

The engine in the pic doesn't look like it. VIN: 1ft7w2b62ceb19234

Okay, that is the engine I have been working with.

Can you post some pictures for me to view of the engine?

Roy

Did you see the video I sent you of the o2 sensor fluctuating? this only happens after the trucks overnight. once it has warmed up it seems to be fine for the rest of the day.

Sorry, could barely see the scan tool and could not see any information at all.

Roy

the man's were jumping from .625 to 253.457.

I resent video.

I meant Ma's were fluctuating.

That was the same video that I cannot see any readings at all.

What were the voltages? That is what I requested from you 2 times.

I need all the readings not just the O2 sensor readings.

Roy

lower o2 sensor volts .805 to o2s12.090 o2s22 .165then both back to .835. o2s11 ma 26.497 o2s12 ma 61.486 jumping to o2s11 ma 250.480 and o2s11 251.479.one if the uppers will be 246.480 and the other will be 2.499.

I only have coolant temperature not voltage. maf flow gr/se 6.60.

right now I dont have any more info. I sent you what I have. I have a friend who is going to change all the o2 sensors this week.

update: I have changed the torque converter, transmission, PCM, throttle body, coolant sensors, intake manifold gasket, all 02 sensors, purge valve, thermostat. it is still stalling once warmed up. no codes. once in a while it will give a cam sensor low voltage error but not often.

A cam sensor dropping out will cause this issue.

You need to go to the connector on each side and verify 5 volt reference and the signal voltage.

https://www.2carpros.com/articles/how-to-check-wiring

Roy

if i keep my foot on the gas pedal it will stay running it is only at idle the RPM's drop. it's like it was shut off. we will check the wiring. thank you.

You are welcome.

Keep me updated.

Roy

it started last night ran for 10 seconds, now it will crank but won't start.

What were the results of the voltage test at the cam sensors?

Roy

I can't get to it until tomorrow.

Okay, keep me updated.

Roy