HELP - 99 Ranger Only Starts Once Every 6 Hours

[hotm6654@hotmail.com]

I have a 99 Flex Fuel Ranger that will only start once every 6 hours. It will start and run a little rough but then if I go somewhere I can't start it again. I did have one obd2 code of P0118. Something about a coolant sensor so I had it flushed. The engine will crank but not start. Since is about every 6 hours I am thinking there must be a bad sensor. Maybe the oxygen sensor?

 

[97RangerXLT]

Why would you think that it would be an oxygen sensor if the code was for a coolant sensor? Flushing the coolant will not fix a bad coolant sensor. However, a bad coolant sensor can give you starting problems. Check the actual sensor, it should be on the lower intake manifold. You might have to remove some of the upper intake stuff to get to it tho. (Not sure where it is exactly on the 3.0)

The good news is that a coolant sensor is fairly cheap. Also make sure you have all the air out of the coolant system, hopefully you took care of that when you flushed the system.

AJ

Sent from my Samsung Galaxy Note 4 while sitting in my underwear

 

[hoosier1104]

I am trying to understand the logic you went through that led you to changing your coolant. Would you mind explaining that?

 

[RayInStl]

My guess is he thought maybe there was some build up on the sensor. Either way, there's no reason to be harsh.

I'm not sure the water temp sensor would be enough to stop the truck from running. It would make it go into closed-loop for sure, but that would just make it run a bit rich, if I'm thinking through this right. If I had to guess, something is getting hot and working again after it cools off. Unfortunately, I don't know what that would be.

Best thing to do is to check fuel pressure and spark when during it's no-start condition and see if you're getting both.

Good luck!
Ray

 

[hoosier1104]

Not trying to be harsh. Just trying to understand the train of thought really. If the computer is throwing a code that the sensor is bad, why not replace the sensor first? That is the logic I would use.

 

[hotm6654@hotmail.com]

99 Ranger Starts Every 6 Hours...

Thanks for the replies. I appreciate any help.

The reason I flushed the coolant was because there appeared to be something like algae in the overflow resevoir. The high voltage code (on the coolant sensor) of P0118 said to me that the engine might not be getting enough coolant because of the junk in the resevoir. One thing I did notice is that it is running pretty rich - seems like more exhaust than usual.

Long story short, I will plan on checking into the new coolant sensor. On the other hand, it seems unlikely that this sensor would cause a problem with the engine starting. Seems like this would stop it from starting completely not just after a 6 hour wait.

Are there any other sensors that might cause this kind of problem?

 

[hoosier1104]

If the computer thinks that there is going to be no coolant, it would probably go into a shut down state and not allow the motor to turn over except after an extended period of time. I recommend changing the sensor first and go from there.

High voltage means something internal to the sensor is bad.