S4s hot starting problem.

[Vulcan Grey]

Hi Alessandro,

 

 

I watched all the videos.  They were very good!

 

Good job showing the freescan IAC, Coolant data, and throttle position.

 

I saw in the "Clear Flood mode" video that you were pushing the pedal to 100%, but it wasn't sure if you were doing that while cranking for a bit, and then take your foot off the pedal and try to restart the engine?  It seemed that the engine did restart soon after?

 

It definitely sounds like a flooded engine, but the clear flood mode didn't seem to help much.  But it also sounded like you might not be getting any fuel.

 

After you adjusted the IAC, it is now a bit low, since it went below 20.  The Engine will be easier to start and idle if you can get it 20<IAC<40.

 

Since you said you do have 3 bar fuel pressure at the rail, then next you need to look for leaking fuel injectors or clogged fuel injectors.

 

For this test you'll need to unbolt the Chargecooler box and lay it over to the side (leave the water hoses connected).

 

The unbolt the 2 bolts on the fuel rail, leave the fuel injectors clipped into the rail!  And pull the 4 fuel injectors out of the holes in the intake manifold.  Place paper towels under the injectors. 

 

Pressurize the rail by turning the key, but DO NOT start the engine. and look for fuel leaking out onto the paper. There should not be any fuel coming out of the injectors.

 

Then try cranking the car again, and make sure there is a fuel wet spot under each injector.

 

I saw that your dash coolant temperature gauge did not match the ECU coolant gauge.  I would check your dash sensor by placing it in boiling water, since boiling water is always ~100C.

 

or use an Ohm meter

 

coolant sensor

 

C      OHMS

_______________

100    185

70     450

38    1800

20    3400

4     7500

-7   13500

-18  25000

-40 100000

[alex-975]

hi Travis

I did as you say

with the contact on the injectors do not drip

1 and 4, however, the wet little by little

2 and 3 no loss

I do not think it is a great loss

letting the engine turn the jet equal to all 4

Tomorrow, however, I take them to a specialist

[alex-975]

hi Travis

injectors controlled by specialist

says they are perfect

other ideas?

coil pack?

spark plug wires?

[Vulcan Grey]

It could be the crank sensor above the flywheel.  It may have an intermittent sort or open in the wiring.  It could be that the heat causes expansion so the signal gets too weak.  The data you sent me from garage and running didn't show any problem with the crank sensor, but you should look at it when the engine is warm and won't start.

 

Also you mentioned new Denso spark plugs.  I use the original NGK BPR6EKN copper plugs, since copper is a better conductor.

 

Have you looked at the spark when the engine is warm?

[alex-975]

Trevis

give me your recordings data FreeScan

heating and on the road?

thanks

[fjmuurling]

I would take out the Denso iridium spark plugs and put in the NGK BPR6EKN sparkplugs. If you google / compare pictures of the two sparkplugs you can see they are very different from eachother. The Esprit likes the big "fat" electrodes of the NGK plugs.

[Bibs]

I used the very expensive Iridiums and they weren't much cop, should have stuck to the originals! 

[alex-975]

hi friends

I tried the old water sensor

put in the pot at 100 ° showed 80 °

replaced with lucas snb110 but same problem ..... it is the sensor or gauge?

the new sensor lucas is right?

I can just feel the NGK spark plugs

I only have 2

I thought may be the knock sensor?

thanks

[Vulcan Grey]

you had ~13 knock, which is pretty normal, and not bad, as long as it isn't increasing.

 

The dash gauge for coolant and temperature won't effect the engine.  The coolant sensor under the intake manifold to the ECU can effect how the engine runs, but your's looked fine.

 

Can you use an Ohm meter to look at the resistance of each spark plug wire?

 

Also, use freescan to record data while the engine won't start.  We should see if the crank sensor is not working.

[alex-975]

days back I sent you FreeScan files on your email

[alex-975]

looks FreeScan file with ignition problems pag2 file GARAGE

[Vulcan Grey]

Oh yeah, I forgot Garage.csv had stops and starts.  I'll look again.

[alex-975]

hi Travis

I saw garage.csv

when the engine will not turn ratio A: F very high

when finally the engine starts ratio A: F is lowered

Petrol does not arrive?

Is this normal?

[Vulcan Grey]

A:F in freescan means what is "desired" by the Ecu, it in not the measured A:F. You would need a wideband O2 sensor and A:F meter to see the real ratio.

[alex-975]

What about the knock sensor?

does it work?

[Vulcan Grey]

Yes, I think your knock sensor works fine.  You are getting up to 13 knock on the garage file, which is not bad for an Esprit. But 0 knock on the street file. 

 

I looked again, and it looks like the cranks sensor signal might have been lost just before the engine died the first time in garage.csv.

 

So if your record more data, set freescan to record at 100ms or faster if possible, start recording above 70C where the engine often won't re-start. Record some data with engine running, then turn the engine off, and try to restart it all while freescan is running.

[alex-975]

a mechanic friend of mine told me sensor crankshaft

[Vulcan Grey]

Did you already replace it?  I definitely think it is worth replacing at this point.

[alex-975]

would like to replace the sensor

there is an alternative to the original part?

[Vulcan Grey]

1995 Corvette ZR-1 crank sensor

http://www.amazon.com/OEM-96055-Crank-Angle-Sensor/dp/B000CSW4YK/ref=au_as_r?ie=UTF8&Make=Chevrolet%7C47&Model=Corvette%7C440&Year=1995%7C1995&carId=012&n=15684181&newCar=1&s=automotive&vehicleType=automotive#productDetails

 

AC Delco 213153

 

also Standard Motor Products #PC7

http://www.rockauto.com/catalog/moreinfo.php?pk=40418

 

Alternate/OEM Part Number(s): 10456043, 10456243, 10456403, 10456555, 10457661, 1103661, 213148, 213153, 8011036610, 8104560430, D8002

[Vulcan Grey]

Though maybe you should look at the wiring to the crank sensor first, since this appears to be temperature related.

 

When it works, the crank sensor looks like it is working fine. 

[alex-975]

What do you advise me to do?

[Vulcan Grey]

I would look at the crank sensor, remove it, clean it.  Look for corrosion or loose connection.  And then if it looks like it is bad, then replace it. If not, trace the wiring back to the ECU and verify the wiring is good.

 

The crank sensor wires go to the Direct Ignition module behind the coil packs, so you can check their wires to that point.

 

Here are some steps from the EMH manual.

 

12. The flywheel sensor should output a voltage

as the crankshaft turns. If no voltage is

produced, the indication is a poor sensor

connection or faulty sensor.

13. The flywheel sensors core is a magnet,

therefore, it should be magnetized and the

resistance should be within a range of 950 to

1200 ohms.

[alex-975]

hi Travis

I checked the sensor wiring is ok

I cleaned the sensor (ohms correct to cool)and replaced (it was dirty), the same problem will not start hot

view this recording FreeScan

it is normal for the rpms are at zero when the engine is running and will not start?

file not starting

not starting.csv

[Vulcan Grey]

Hi Alex,

 

There is not enough data there, since the ECU never registers any RPM.  

 

It looks like the crank sensor is registering signal.  But you never get to 700+rpm for the ECU to take over from the Direct Ignition module.

 

It could be that you have a bad D.I. module. Or bad coil packs.  It would be best if you have a friend to swap these parts in order to trouble shoot which part is causing the problem.

 

It could be spark plug gap, if incorrect.  What is your spark plug gap set at?  How do the spark plugs look?

 

I saw your TPS throttle position sensor working in the video, but the voltage is high on "street.csv", "not starting.csv", and "garage.csv".  Should be between 0.45V to 0.7V when throttle is closed.  Otherwise it is working normally.  But that might mean that you have the throttle cable adjusted too tight.