Smash_

I have a no start issue doesnt happen all the time but it will crank but wont fire. What could this be?

Plutoe

fuel pump, fuel rail pressure,drive authorization system bla bla bla---find someone that understands the car and has the correct diagnostics!!

PS: If you see sheep or goats out back keep looking!!

cal1

Add crankshaft positioning sensor to the list. Put it near the top. Does the no start issue occur most when the car is hot?

Smash_

Doesnt mattter if hot or cold. Theres a new symtom now, itll be running fine then it just dies and wont start but if I wait no discriminate amount of time it will fire back up. Sometimes 10 mins sometimes 2 hours....

cal1

Crankshaft positioning sensors tend to not work when hot and then work again when cool so that makes a bad CPS less likely.

Can you get codes pulled? If nothing else, the dealer will do it for what I have heard is a reasonable price. sorry I am not more familiar with the W163.

Smash_

I checked the fuel rail and there's pressure and fuel there. I'm unsure how to check the fuel pump. My wife seems to think if you jiggle the keys in the ignition it'll fire up (worked for her a couple of times) so would my ignition Gabe anything to do with it.

Maj. Dundee

Checking the fuel pressure by pressing the valve at the fuel rail is not a valid test for fuel pressure.

Working with a cold eng., turn the key to pos. #2 and wait 15 secs., then attempt to start the eng.

If the eng. starts then it is a fuel delivery issue, pump or filter, not an electrical or key issue.

Smash_

Ok I will do try that but where Im confused at is the random dying then it ll fire right bak up sometimes and otber times it doesnt and I have to wait anywhere from a few minutes to a few hours...

Maj. Dundee

You should have posted this info originally.

If that is the case then you could have a faulty Crankshaft Position Sensor.

cal1

Hey Maj. I was thinking CPS also, but OP reports no relationship between the car being hot and no start condition and then start after cool down. Also "running fine then it just dies" isn't consistent with bad CPS as far as I understand. Maybe multiple issues.

Sure would be nice to know codes. Hey OP, do you have a friend with a code reader? The standard units might pull some codes. Really takes STAR or DAS/Zentry for comprehensive reading of fault codes.

Smash_

I don't have anybody that has a code reader where would I find one... Also the random dying just started thats why I didnt post it earlier.

Smash_

could the cam angle sensor be the issue?

Maj. Dundee

No, it's a long shot.

Maj. Dundee

Whatever veh. you own these days, a scanner is a must. With this scanner you will be able to read and clear every M/B code in every category.


A quick test for the Crankshaft Pos. Sensor (CKP) is as follows: when the problem occurs, turn the key to start, all the time watching the Tachometer gauge and see that the needle moves/bounces to at least 250 RPMs.

If it doesn't then it is the CKP, if it does then it is probably a fuel delivery issue. But in any case you still need a scanner.

Smash_

Just wanted to update it did turn out to be the crank angle sensor thank you guys for all your help!

cal1

Glad you got the problem resolved.