Fuel Injector Problem 1989 4.0

[jon1998]

After the vehicle is completely turned off, I can hear clicking eminating from the engine. I put a screw driver to the individual injectors and my ear to the screwdriver, using it like a stethoscope, and I could hear the injectors make a clicking sound. This is with the vehicle completely off. Do you guys have any ideas as to what may be causing this to happen? The Jeep is also hard to start after being warmed up. I'm wondering if the injectors are flooding it.

[Dzimm]

How long do they click after it is shut off? To test if it is being flooded, drive it around then shut it off and pull a spark plug. If they really are continuing to inject and flooding it, the plug would be covered in gas.

 

If they are still firing you may also be able to see it by shining a light in the spark plug hole.

 

Also does the clicking have a pattern or is it speratic? All vehicles click and pop when shut off because of the metals shrinking and fluid dripping. Your screwdriver may have just amplified those sounds.

[cruiser54]

You are most likely hearing the ticking of the cooling exhaust manifold which is very common.

 

I bet it's telescoping through the intake manifold.

[jon1998]

How long do they click after it is shut off? To test if it is being flooded, drive it around then shut it off and pull a spark plug. If they really are continuing to inject and flooding it, the plug would be covered in gas.

 

If they are still firing you may also be able to see it by shining a light in the spark plug hole.

 

Also does the clicking have a pattern or is it speratic? All vehicles click and pop when shut off because of the metals shrinking and fluid dripping. Your screwdriver may have just amplified those sounds.

The clicking sounds speradic, but also too rythmic to be shrinking metal. It also clicks regardless of whether the engine was shut off warm or cold. Thanks for the idea about pulling the spark plug, I will try that.

[Ωhm]

Pull Fuel Pump Relay (Injector Feed) and see if injector clicking stops.

[Dzimm]

 

How long do they click after it is shut off? To test if it is being flooded, drive it around then shut it off and pull a spark plug. If they really are continuing to inject and flooding it, the plug would be covered in gas.

 

If they are still firing you may also be able to see it by shining a light in the spark plug hole.

 

Also does the clicking have a pattern or is it speratic? All vehicles click and pop when shut off because of the metals shrinking and fluid dripping. Your screwdriver may have just amplified those sounds.

The clicking sounds speradic, but also too rythmic to be shrinking metal. It also clicks regardless of whether the engine was shut off warm or cold. Thanks for the idea about pulling the spark plug, I will try that.

The exhaust manifold will click and shrink no matter how long the engine runs. It heats up within only a few seconds and can sound somewhat rhythmic when shrinking. The fuel injectors will for sure be a rhythm though. I'm with Cruiser that it's probably just the exhaust manifold making the noise but it's worth a look into the injectors just in case.

 

I have had issues similar to yours with my 98 XJ not starting after it had run. It was so inconsistent when it happened though so idk what finally fixed it. I know that some sensors like the cps can be affected by heat. It's possible that heat soak is causing a sensor to act up after you run it.

[jon1998]

 

 

How long do they click after it is shut off? To test if it is being flooded, drive it around then shut it off and pull a spark plug. If they really are continuing to inject and flooding it, the plug would be covered in gas.

 

If they are still firing you may also be able to see it by shining a light in the spark plug hole.

 

Also does the clicking have a pattern or is it speratic? All vehicles click and pop when shut off because of the metals shrinking and fluid dripping. Your screwdriver may have just amplified those sounds.

The clicking sounds speradic, but also too rythmic to be shrinking metal. It also clicks regardless of whether the engine was shut off warm or cold. Thanks for the idea about pulling the spark plug, I will try that.

The exhaust manifold will click and shrink no matter how long the engine runs. It heats up within only a few seconds and can sound somewhat rhythmic when shrinking. The fuel injectors will for sure be a rhythm though. I'm with Cruiser that it's probably just the exhaust manifold making the noise but it's worth a look into the injectors just in case.

 

I have had issues similar to yours with my 98 XJ not starting after it had run. It was so inconsistent when it happened though so idk what finally fixed it. I know that some sensors like the cps can be affected by heat. It's possible that heat soak is causing a sensor to act up after you run it.

 

The heat soak issue is pretty frustrating since it runs great otherwise . I'll go to the store and 20 min later it will have trouble starting, misfire, shake, and idle real low until it starts driving again. I haven't checked the CPS yet, I'll try that too. 

[Dzimm]

The heat soak issue is pretty frustrating since it runs great otherwise . I'll go to the store and 20 min later it will have trouble starting, misfire, shake, and idle real low until it starts driving again. I haven't checked the CPS yet, I'll try that too.

Yeah sounds like a sensor to me. Run through the checks for sensors both while cold and after it runs and warms up, preferably when you are having trouble getting it started. Just remember, whatever you do, don't just throw parts at it. That gets expensive and frustrating.

[cruiser54]

 

 

 

How long do they click after it is shut off? To test if it is being flooded, drive it around then shut it off and pull a spark plug. If they really are continuing to inject and flooding it, the plug would be covered in gas.

 

If they are still firing you may also be able to see it by shining a light in the spark plug hole.

 

Also does the clicking have a pattern or is it speratic? All vehicles click and pop when shut off because of the metals shrinking and fluid dripping. Your screwdriver may have just amplified those sounds.

The clicking sounds speradic, but also too rythmic to be shrinking metal. It also clicks regardless of whether the engine was shut off warm or cold. Thanks for the idea about pulling the spark plug, I will try that.

The exhaust manifold will click and shrink no matter how long the engine runs. It heats up within only a few seconds and can sound somewhat rhythmic when shrinking. The fuel injectors will for sure be a rhythm though. I'm with Cruiser that it's probably just the exhaust manifold making the noise but it's worth a look into the injectors just in case.

 

I have had issues similar to yours with my 98 XJ not starting after it had run. It was so inconsistent when it happened though so idk what finally fixed it. I know that some sensors like the cps can be affected by heat. It's possible that heat soak is causing a sensor to act up after you run it.

 

The heat soak issue is pretty frustrating since it runs great otherwise . I'll go to the store and 20 min later it will have trouble starting, misfire, shake, and idle real low until it starts driving again. I haven't checked the CPS yet, I'll try that too. 

 

If it was CPS, it wouldn't start. 

 

You could have leaky injectors that don't close completely when the engine is shut off.

 

Get a refurbished set of Volvo 746 injectors and eliminate that issue.

 

A coupla guys on Cherokee Forum supply them. 

[Dzimm]

If it was CPS, it wouldn't start.

 

You could have leaky injectors that don't close completely when the engine is shut off.

 

Get a refurbished set of Volvo 746 injectors and eliminate that issue.

 

A coupla guys on Cherokee Forum supply them.

The CPS can be intermittent. Especially if it became susceptible to heat. Sometimes it will start warm but most of the time it will have to fall below the threshold of heat before it will start.

 

Either way it's important to test all the sensors given the range of issues they can cause.

 

If you are going to replace the injectors, definitely do as cruiser said, don't waste the money on factory 1 holes.

[cruiser54]

 

If it was CPS, it wouldn't start.

 

You could have leaky injectors that don't close completely when the engine is shut off.

 

Get a refurbished set of Volvo 746 injectors and eliminate that issue.

 

A coupla guys on Cherokee Forum supply them.

The CPS can be intermittent. Especially if it became susceptible to heat. Sometimes it will start warm but most of the time it will have to fall below the threshold of heat before it will start.

 

Either way it's important to test all the sensors given the range of issues they can cause.

 

If you are going to replace the injectors, definitely do as cruiser said, don't waste the money on factory 1 holes.

 

But, it won't start and run rough.......

[Dzimm]

 

 

 

If it was CPS, it wouldn't start.

 

You could have leaky injectors that don't close completely when the engine is shut off.

 

Get a refurbished set of Volvo 746 injectors and eliminate that issue.

 

A coupla guys on Cherokee Forum supply them.

The CPS can be intermittent. Especially if it became susceptible to heat. Sometimes it will start warm but most of the time it will have to fall below the threshold of heat before it will start.

 

Either way it's important to test all the sensors given the range of issues they can cause.

 

If you are going to replace the injectors, definitely do as cruiser said, don't waste the money on factory 1 holes.

But, it won't start and run rough.......

Right. I was more so using the CPS as an example, it's more likely something else but you know how these things can be. Definitely seems like one thing is the problem but turns out it's something completely different.