Engine cranks but does not start?

Hi,

In most cases, a crank no-start condition is the result of either a loss of fuel or ignition spark. I realize you hear the fuel pump, but that doesn't mean it is producing.

So, here is what I need you to try. See if the engine starts with starting fluid. If it does and then stalls, we know it is fuel related. If there is no change, then suspect a loss spark to the plugs.

Here is a link that explains how to check:

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

Try this and let me know the results or if you have other questions.

Take care,

Joe

Thank you for your response. I will try this tomorrow and let you know the outcome. If it helps any at all, after trying to start the truck, I can smell gas. Guess that doesn’t mean it’s getting the correct amount of gas to start the motor. Just blows my mind how it was running just fine then out of nowhere it won’t start. Thanks again for the info and I will let you know more tomorrow.

Hi,

If you smell gas, just check for spark. It sounds like the pump is working.

Let me know.

Joe

So, here’s an update: Got home this morning from work, I checked the spark and had a good spark. I noticed I did not smell any gas. So, I took the top plastic piece off the motor and had my wife turn it over while I sprayed gas into the motor. It started right up when I done that. I let it run probably 15-20 minutes turned the truck off and started it right back up and it started fine. I’m afraid to drive it though because I don’t want to get stranded. Do you think it’s possibly my fuel pump that’s causing the issue?

Hi,

Interesting. We need to approach this from a different direction. If you hear the fuel pump and once started, it runs good, that sounds like it isn't a spark issue but rather a fuel issue.

Let's try this. In the under-hood fuse box, you will find an ECM B fuse and the fuel pump relay (see pic 2). Remove them and inspect where they connect to make sure nothing is corroded, pushed in, or damaged. If everything appears good, switch that relay with a different one in the box that has the same part number. See pic 2 for fuse/relay location.

If there is no change, I need you to check the power to the fuel injectors when it won't start.

If you look below, I attached a schematic showing the injectors. See pic 3. Each injector has a gray wire. Check for power at each injector's gray wire with the ignition key in the run position. You should have power.

Let me know the results.

Take care,

Joe

See pics below.

Okay. so, I checked ECM fuse it was good. I changed out the fuel pump relay and still nothing. If I spray starting fluid into the motor, it will run until I shut it off for at least 15 minutes then it won’t start back. I’m currently going to buy a code reader and see if it’s throwing any codes. I’m at a loss with this stupid a** truck!!

Hi,

Were you able to check if the injectors are getting power? If you did and they are, have a helper try to start the engine while you confirm power is still present at the injectors. You may be losing the injector pulse or power supply when the key is in the start position.

Also, when you start it with starting fluid, do you notice any black or gray smoke from the exhaust? Do you hear the fuel pump prime when you first turn on the key?

Also, I need you to check the spark at the spark plugs. It should be a blue snapping spark. If it is white, orange, or something different, we may have a failing coil or ICM. You need to have a hot spark when starting the engine, especially when the engine is cold.

Let me know.

Joe

Okay, so I changed the fuel pump. It will start now but when it’s idling it sounds good but when you give it gas it sounds like it’s missing bad and will rev limit at 4,000 RPMs. I haven’t driven it yet to see what happens while going down the road, but I can tell something isn’t right. The code reader is only throwing a 02 sensor and a fuel tank pressure censor circuit low voltage. Would those have anything to do with it?

Hi,

Either can affect drivability. However, the fuel tank pressure sensor is more likely because it is tied into the EVAP system.

Could you send me the specific codes you are getting?

Also, if that is a new code, you may have left the connector at the top of the tank loose or not fully connected. I attached a pic of the sensor below. Do you remember connecting it? Also, could you record what it is doing and upload it for me to hear?

If your scan tool has live data, let me know what the short-term fuel trims are when the engine is at operating temp. Also, watch the voltages from the oxygen sensors. They should be between 0.1v and 1.0v and change especially when you hit the throttle.


Let me know.

joe

See pic below.