Engine will not stay running?

Hi,

Have you checked to make sure the fuel pressure regulator is working properly? Also, if you disconnect the vacuum hose to it, is there fuel in the hose, and does the hose have a vacuum when cranking the engine? (See pic 1 below)

The regulator is at the end of the fuel rail. Check the aforementioned things first. Also, make sure the fuel return isn't clogged.

Let me know.

Take care,

Joe

See pic below.

No fuel in vacuum line appears to have suction. Started and ran longer but was sputtering and smoke coming out of exhaust. Fuel pressure was 45 PSI.

Is the exhaust smoke black or dark gray? Also, believe it or not, the fuel pressure is low (see pic below), which leads me to one thing. A sticking injector or injectors.

When you checked fuel pressure and the key was turned off, did the pressure drop quickly? If we have an injector stuck or leaking, that will cause lower pressure and flooding.

Let me know. Also, let me know if you have a live data scan tool. If you do, tell me what the short-term fuel trims are.

Take care and I'll watch for your reply.

Joe

See pic below.

The smoke was dark grey fuel pressure at 45 when key was on and actually went up to 48 when key was turned off. See pictures below. The last picture is where the gauge was connected. The pressure didn’t seem to drop when the key was turned off. Could it be the gauge I bought?

I do not have a live scan tool.

Hi,

The dark gray smoke does usually indicate a rich fuel mixture. Also, the fuel gauge is likely correct. How long did you wait to see if the pressure would drop after turning the key off?

Also, did this issue just start after the engine repairs? If it did, it is most likely related to the injectors. I'm sorry to ask, but is it possible to get your hands on a live data scan tool? I don't mean to purchase one but to borrow one.

The issue could even be the engine coolant temperature sensor. Check to make sure the wire to the sensor isn't pinched or damaged and shorting. If the ECM thinks it is neg 40 degrees F, it will dump fuel to make it run. Keep in mind, the vehicle has two coolant temperature sensors. The one of interest can be seen in the attached pic and is used by the ECM.

Let me know.

Joe

See pic below.

Have been unable to get alive scan tool. The pressure dropped about 8 lbs over an hour. The problem did start after the engine was rebuilt. The temperature sensor is cracked a little. Guess I should replace it.

Hi,

No problem. The coolant temperature sensor should be replaced. The engine coolant temperature affects most systems the PCM controls which includes fuel injection.

Let me know if that takes care of the issue.

Joe

The oil is completely saturated with fuel and over full. I don’t want to damage anything else! Should I drain some of it? I don’t want to change it completely if the problem is not fixed!

Hi,

If it is saturated, drain it. I would drain all of it and place an inexpensive oil in it. If there is that much fuel in the oil, it will be very thin.

Let me know.

Joe

Replaced sensor and oil. It cranks but doesn’t start now. I am going to pull spark plugs and check cylinders for fuel. They are new spark plugs.

Hi,

Did you lose spark to the plugs? Here is a link that explains how to check:

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

Let me know. Also, let me know if the plugs are wet or not.

Joe

Spark is good and plugs are wet. Trying to find a way to siphon cylinders out. Completely frustrated!

When you reinstall the plugs, remove the fuel pump fuse and see if it will run for a few seconds. Hang in there.

Also, when you reinstalled the fuel lines, is there any chance you may have reversed the return and supply?

Let me know.

Joe

It will not run. Double checked spark. Good on all six cylinders. Plugs 2, 5 and 6 are wet with fuel. Plugs 1, 3 and 4 seemed dry. As far as the fuel lines the return one is shorter than the supply one. I don't think I could get them reversed.

If you have spark at all plugs, then it likely is not getting enough fuel. The idea that 2, 5, and 6 are wet leads me to think they aren't getting spark. However, you confirmed they are.

Do me a favor. Each fuel injector will have a solid pink wire to it. Confirm there is 12v to each pink wire. There is a second wire as well that will be different colors by the cylinder. See pic below. That wire provides a ground path to the PCM to complete the circuit, time the injection, and adjust the air/fuel mixture based on conditions.

If the pink wires all have power, check the other wire on the cylinders having wet plugs and see if it has a constant ground. If it does, that is the problem.

Let me know.

Joe

There are 11.97 volts to each injector. Not sure what you mean by constant ground? Between the pink and ground wires there is 6.06 volts on all of them.

When I meter the ground wire to the frame or negative side of battery it reads open.

Hi,

With the key off, if you place the voltmeter between the two wires from the connector, you have 6V? You shouldn't have anything because the low reference from the computer shouldn't be supplying power.

Let me know. Also, I was wondering if there was a constant ground that would allow the injector to continuously inject fuel.

Let me know. Also, check the wire (other than the pink) for continuity to ground. You should have an open circuit until the ECM provides the ground path.

Let me know,

Joe

With key off no voltage between wires. No continuity with ground except for the pink wires.

Hi,

Okay, that sounds normal so far. You should only have power to the pink wires when the key is on.

Here is how the ground works. It is called a low reference ground. It is called low reference because it is a ground path being provided via the PCM and isn't a consistent ground until the PCM provides it. That is how the injectors pulse fuel.

So, to check for ground, you need to check it with the engine cranking. Disconnect the injector. You will need to get what is called a Noid light and attach it to the wiring connector on the engine side. When cranking, the light should pulsate on and off. You could try to use a regular test light, but it is hard to connect both sides,

As far as the Noid light is concerned, most parts stores will lend one to you.

Let me know what you find or if you have other questions.

Take care,

Joe

We'll all injectors pulsated with Noid light. Not sure what to do next! I guess it could be possible bad spark plugs but they are new.

Hi,

If we have spark and fuel, the timing is correct, there is one thing left, compression. I realize the engine was rebuilt, but the issue started after the work. Have you checked compression in the affected cylinders? If not, that is what I would check next.

Here is a link that explains how it's done:

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

Let me know what you find. Also, if you could record it cranking and upload it for me to hear, it may help.

Let me know.

Joe

I will need to do this with spark plugs in correct? Except for the cylinder I am testing.

Hi,

All spark plugs should be removed when testing.

If you look at the pics below, they are the directions specific to your vehicle right from the repair manual. Take a look through them and let me know if you have questions.

Take care,

Joe

See pics below.

Everything says normal operating temperature. How can I do this if it won’t run? Also when I pulled off the rubber boot between the air filter and the throttle body it had antifreeze in it. I am so confused. Engines used to be easy to rebuild!

Also, do you want the spark plugs in or out when I record it?

Hi,

The fuel injection system has coolant passages in the throttle body, The coolant flow improves cold drivability. As far as it being at operating temperature, we can mentally make adjustments in our heads if what is found is acceptable.

When you record it, have the spark plugs in so I can hear how it is reacting with compression,

Let me know.

Joe