Engine won't start, Fault tracing with Vida.

Chassis · Post by **Chassis** » 14 Dec 2016, 07:19

Hi All,
Recently my daughter have had a few issues with her -03 140 hp (240000 km). First problem was unstable/rough idle. I scanned with Vida/Dice and found that inlet manifold pressure did't match the MAF readings. Searched and found a cracked hose to the manifold sensor. Replaced it and took it for a ride. This time the engine ran rough with weak performance. Scanned, found a brooken ignition coil and replace it. Now when everything is supposed to be fine the engine refuses to start. No signs of ignition. Battery is charged and starter seems to run just fine.

Any idea?

I'm not so familiar with Vida but is it possible to check fuel pressure, test injectors, test for sparks etc?

My daughter needs her car so I'm thankful for all answers. In particular good ones:)

Regards, Chassis

Post by **abscate** » 14 Dec 2016, 08:15

Hello Chassis

The two most common things for a no-start are lack of fuel and lack of spark.

Try some starting fluid, about a 1-2 second shot, into air cleaner to see if you get some firing. That will help diagnose a fuel delivery problem.

It might be good to pull all the spark plugs and see if they are firing - its common to have more than one coil go bad.

Chassis · Post by **Chassis** » 14 Dec 2016, 10:43

Tested to drip some gas into the inlet. No firing whatsoever. Next is to test for sparks. Don't know yet if it's possible to pull one of the coil out without extention harness. Gonna check it tomorrow. Thanks for the reply:)

Post by **abscate** » 14 Dec 2016, 12:17

Gas won't really work as a test for fuel delivery. Too much gas is as bad as too little.

Your car has what Is called " coil on plug" ignition here. There is one coil for each cylinder. You undo an M6 bolt ( important that these are tight when you reinstall) and they just pull up.

If you undo the spark plug, touch it to the block and have an assistant crank the engine you can check spark

Do it for all five cylinders

Chassis · Post by **Chassis** » 14 Dec 2016, 14:38

Thanks, I'll let you know the outcome tomorrow.

Post by **mrbrian200** » 15 Dec 2016, 02:37

abscate wrote:Hello Chassis

The two most common things for a no-start are lack of fuel and lack of spark.

If it appears neither (fuel pressure on rail but no injector pulses, no spark across all 5) suspect cam/crank sensor(s). If it can't determine TDC/position/timing I believe nothing happens: no spark, no injector pulses (no gas). This would be inline with drivability issues immediately preceding to sensor total failure. I doubt all 5 coils would fail at the same exact time unless they lost common ground or a fuse popped. That ground is split between two ring terminals not one. You did replace one coil if everything else good it should still 'spit' even if it doesn't run unless there's a major vacuum leak or the throttle plate is stuck open. Or no fuel pressure on the rail (which can be seen in VIDA).
You're probably looking at no fuel pressure on rail (for any number of reasons), blown fuse/bad relay (check all relevant), or cam sensor.

Hose to MAP may have looked cracked, I bet the ecm tries to adapt to minor leaks there. You can try resetting the ecm but it wouldn't be responsible for no start.

Chassis · Post by **Chassis** » 16 Dec 2016, 10:08

This is weird.
- It has intense bright spark. Checked only cyl #1 though.
- All spark plugs are clearly wet and are smelling gas when removed.
- Still no codes
- Still no signs of ignition.
Is there anything else I can check with Vida/Dice or other method?

Post by **mrbrian200** » 17 Dec 2016, 10:38

Either the timing is way off or too much/too little air. '03 uses the Bosch style throttle body. I've had my experience with this and it threw me for a loop for a good month until I figured it out. Key position II look at the actual throttle plate position (I forget what it's called in VIDA, but it's labeled something close to that) and the accelerator pedal positions. Check the pedal position as seen in VIDA seems appropriate as you slowly press the pedal. Then look at the throttle plate positon. Key on Engine off this is a sweep test and throttle plate opens/closes proportionately to pedal position. 'closed' should be less than 5%. If it's stuck open enough to prevent starting it would be 20% or more. My experience if it's stuck between 7-20% it will still start but with very rough 'choppy' idle quality. If the throttle plate appears to be working properly then you've got a massive vacuum leak somewhere or the timing is off.

Note when I had problems with this the computer never once spit a code for the throttle body, but had me chasing circles around everything else (rich/lean, MAF codes, terrible idle quality, sometimes no power/would cut out at higher RPMs). If it's stuck in an open positon the problem is internal wear you have no choice but to replace it. If it's stuck closed you can try cleaning the throttle body first but I would suspect in more cases than not the underlying issue gets back to internal wear (you'll still end up replacing it). Mine was bad at 10y/80k miles, and I suspect is the primary reason PO got rid of it, their mech was stumped and the car wouldn't pass IL emissions. Was intermittent in nature on mine but goes without saying for others it could fail more quick/consistent like.