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rpmdiag
rpmdiag, Tech and Instructor
Category: Volvo
Satisfied Customers: 6878
Experience:  Since 1975
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S40 will not start after driven while it will try to turn

Customer Question

S40 will not start after driven for a while it will try to turn over but does not start.
Submitted: 5 months ago.
Category: Volvo
Expert:  rpmdiag replied 5 months ago.

Hi, I’m Ron and I can help you.
I have been in the auto repair business with my own shops since 1975 and also teach automotive repair. I am confident we can resolve your problem together. Please understand that I don't know your skill level. In most cases when you have a problem with the way the vehicle performs, specialized tooling is required to acquire computer data/information or engine testing results. We didn’t build these complicated vehicles; we just diagnose and fix them. Also understand that I can't see, smell, hear, or touch the vehicle either, so it may take a few replies to get to satisfactory results. I am also going to direct you with the fastest, easiest and most common things to check first. Please be patient and permit me to do what I do best.
I also try to give all of the information you may need, expecting a “positive rating” in return. I will also continue assisting you after you have rated me, if necessary. If there is any reason I cannot get a positive rating, please let me know why “in advance”, so I can go another direction for you. I am sorry you’re having this problem; I’ll help you through it.

We're losing either spark or fuel. At the time it does not start, you need to be ready with a spark tester attached to a plug wire, and also a fuel pressure gauge attached to the fuel rail. In most cases, the CRANK sensor overheats causing a loss of spark.

Thanks, Ron

Customer: replied 5 months ago.
After car cools down it will start could this be a bad crank sensor or starter control module
Expert:  rpmdiag replied 5 months ago.

Could be a bad crank sensor or the armature on the fuel pump can also be bad, that's why i recommended the tests I did.

Thanks again, and please don't forget to rate me and keep this link in case you need me again later on.

Ron

Customer: replied 5 months ago.
Is this a common problem in Volvo I just had the timing belt and water pump changed and now this has started happen. It has been at the mechanic and he is not sure what it is. It is not giving any codes
Expert:  rpmdiag replied 5 months ago.
Common problem for many cars.
Codes don't alway set for parts like these.
Thanks
Ron
Customer: replied 5 months ago.
When it has the no start issue the computer is showing 0 on everything including voltage could it still be sensor or could it be a computer problem
Expert:  rpmdiag replied 5 months ago.

Either, we need to start with the easiest and most common things first. You can attach a scan tool and get immediate information too.

Ron

Customer: replied 5 months ago.
It is not the crank sensor it is new and still having the same issue.
Expert:  rpmdiag replied 5 months ago.

That may be true, but i think enough guessing has been done. We need to address this with the proper tooling. Don't you agree?

Thanks again, Ron

Customer: replied 5 months ago.
The car has been at the mechanic for 4 weeks I am asking you as an expert for assistance. Because he is stumped by this
Customer: replied 5 months ago.
How should he address this
Expert:  rpmdiag replied 5 months ago.

Okay, here are the snap shots of a crank sensor and a pump.

Please rate me now for my time and I can continue to assist you if you need me to.

Thanks again, Ron

Customer: replied 5 months ago.
It is not the crank sensor the mechanic changed it and we are still having the same problem... What should we look at next. Like I said it will start and run fine when you shut it off it will not start back for atleast an hour. It will try to turn over but computer says it is getting no voltage. What can this be...
Expert:  rpmdiag replied 5 months ago.

That means nothing, are you willing to test these parts with a scope or not? Please let me know.

Ron

Customer: replied 4 months ago.
What kind of scope are you talking about. The shop has put this on a computer and they are not sure. I brought car to shop for oil leaks this problem occurred after they had to take apart engine several times. I figured if I could speak to an expert on Volvo I could have some kind of understanding about what the problem could be.
Expert:  rpmdiag replied 4 months ago.

A lab scope that takes shots like I sent you. If they did something wrong during your last repair which is what this sounds like, I wouldn't know that, and that's usually the case too.

Thanks, Ron

Customer: replied 4 months ago.
Mechanic ran a scope and said it is not the fuel pump. He also thought it could be the theft system but it tries to turn over what else could it be.
Expert:  rpmdiag replied 4 months ago.

The security system will act intermittently too. It needs to be addressed.

Thanks again, and please don't forget to rate me and keep this link in case you need me again later on.

Ron

Customer: replied 4 months ago.
If it is the security system would it do it every time after driving. And it does try to turn over. It acts like it is not getting enough gas. But if you wait about an hour it cranks up fine.
Expert:  rpmdiag replied 4 months ago.

I said it can act up intermittently

Customer: replied 4 months ago.
Ok well it not acting up intermittently it happens every time you drive the car. It will start up fine then after driving and you shut it off it will not start. This happens every time and it seems like it is trying to start but it doesn't. However if you go back in an hour it will crank up perfectly.
Expert:  rpmdiag replied 4 months ago.

Okay at least have your mechanic to a reset for your security system. You can even try this one your self before you do that, see attachment. If that doesn't work, I can opt out to see if someone else can help you.

Thanks again, Ron

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