Mechanics

NISSAN SENTRA ENGINE PROBLEM

2003 Nissan Sentra • 165,000 miles

2003 Nissan Sentra turns over but will not start. It has no spark at the plugs. Replaced Crankshaft sensor with no change. Used old Crankshaft sensor to replace Camshaft sensor (same part) with no change. All fuses look good. Can hear fuel pump when starting. No engine codes that I can see. The engine was very clean when I received the car.

The lady I am helping (owner of car) informed me it all began with her engine overheating. She said someone took a look at it and kept it for 3 weeks. This person was only able to work on it off and on. He took the head off and checked it out. I understand everything looked ok. There was no answer for why it overheated. She got the car back and it ran fine for a week. Then it began to hesitate on acceleration. The engine would die at times but she was able to restart and go. Then it just got to the point where it could no longer be started.

I am just a shade-tree mechanic looking to help the poor girl out. Do you have any thoughts on next steps?

Thanks, Jim
Avatar
Guest
November 15, 2012.




Lets check a couple of things ok. If you would unplug the mass air flow unit and see if it will start. Do you have a digital voltage ohm meter? I would like to run a couple of test ok. If you would check the computer harness and make sure it is plugged in tight. Get back to me and we will go from there ok.

Racefan966
Nov 15, 2012.
I disconnected the connector from the mass air flow unit (at air intake near filter) and attempted to start the engine but no go. I do have a digital voltage ohm meter. In order to check the computer harness of which I believe you are referring to the ECM module I will need to remove the glove box as from what I can see the ECM module is located behind the glove box yes?

Tiny
Jwallycars
Nov 15, 2012.
Have you tried starting fluid yet? Try spraying some in the intake. Does it try to start? It's no you definitely have a spark problem. If yes then your problem is in the fuel system.

Cadieman
Nov 16, 2012.
Is it an ok thing to spray starter fluid in the air intake? Looks like a long path for fluid to move down an indirect path to reach the cylinders. Does not seem that method would work as well as an engine with a carburator. I do know it is getting gas as I connected a pressure guage to the fuel rail input and there is fuel pressure there (I was unsure of the actual readings being correct however because they varied from high to low and it did not hold steady after turning the key to on). I did disconnect the fuel line at the rail and turned the ignition to on and it did pump gas into a container.

Tiny
Jwallycars
Nov 16, 2012.
It is safe this car does not have a carburetor. It runs off fuel injectors this is an easy way for you to check if you the injectors and fuel pump are working if it tries to start. The problem is the fuel pump or the injectors. And if it doesn't try to start the problem is in the electrical or in the engine.

Cadieman
Nov 16, 2012.
Hi - I did try the starting fluid but it is still no go. Did not even try to start. Turns over but that is it. So it does sound electrical for sure. Any idea on next step?
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Tiny
Jwallycars
Nov 16, 2012.
In the rear of the motor that long round tubular piece is the intake. You loosed the clamp and pulled the hose off. Then sprayed the starting fluid and the hole. Then put the hose back on leaving the clamp loose. Then you tried to start the car and my right.

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Cadieman
Nov 17, 2012.
Yep - I had to remove the intake hose running between the air filter and the intake manifold. There was a valve I needed to open. When I opened the valve I sprayed in the starter fluid. Then I quickly put it loosely back together and went through the starting routine with no success. I cannot spray the started fluid in when attempting to start as the valve closes.

Tiny
Jwallycars
Nov 17, 2012.
I have gone as far as I can with model, feel free to contact my boss. Just click on your name on the page and email him. Im sorry his name is mike@2carpros.

Cadieman
Nov 18, 2012.

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