audia4free

-Fuel pump is new
-Ignition Coil packs are new
-New NGK iridium spark plugs new

And the engine cranks as if its gonna start anytime even the revs go up a little bit, but it just simply doesn't start, any ideas??

2002 Audi A4 Base 3.0L V6 AVK engine

lyleswk

Mine did this and was the ESS, Engine Speed Sensor. You can confirm this with either a VAGCOM or generic code reader or just go for it. DIY here:

http://www.a4mods.com/index.php?page...eedsensor.html

Huey52

It can often be the engine drive shaft speed sensor (ESS) not properly reporting to the ECU. Also the Mass Airflow Sensor (MAF) may need to be cleaned (electronics cleaner spray and don't touch the element itself). Worst case would be low compression.

audia4free

well, I tried a generic code reader today, and it doesn't throw out any codes, that is really weird since I have a bunch of things disconnected such as the radiator fans and the headlights and stuff, but it doesn't show any code, I will clean the MAF today and see what happens, if that doesn't come up well I will hire a mechanic to check the compression of the engine, Thanks guys any more ideas???

audia4free

Ok guys I cleaned the MAF and end up checking the CKP sensor and it doesn't make a difference whether its connected or not... I am really frustrated right now, any more ideas guys please...

Huey52

The only other thing I can think of, and it is rare, is that your starter motor is degraded and not spinning as fast as necessary.

Of course I presume you have already checked the capacity of your battery (and not just the instantaneous voltage). An autoparts store such as AutoZone will check the capacity for you.

And also presume that after changing coils/'plugs you assured the proper firing order of the 'plug cable attachment.

Battery-coils-'plugs-'plug cables-starter

lyleswk

Could be starter, but since the generic reader didn't find anything, I would recommend you get a VAGCOM download. As a note, a generic code reader will only read items required by the EPA (I think) for emissions. The VAGCOM reader will read these codes as well as all of the VW / Audi specific codes. That is why all of the things you have disconnected are not registering on the generic reader.

By the way, disconnecting the ESS won't help diagnose it as the engine will not fire off if it does not see an accurate crank position. Whether it is failed or disconnected, the ECU is seeing nothing. Other sensors (like the MAF) if disconnected will cause the ECU to go into a limp mode, but not the ESS. ...Or at least that is my understanding...

Huey52

That's correct. The ECU needs to see a sensed shaft speed/position otherwise it will not start as an engine self-protection measure.

audia4free

Thanks a lot guys you sure are the best honestly, well yesterday I found out that apparently a sensor that it is connected I dont know if it is the alternator or something I took some pictures and I will post them so you can help me out, it is located close to the oil filter

audia4free

This is one of the two connections I found out that they are disconnected I guess

http://img88.imageshack.us/i/dscf1284ln.jpg/

http://img543.imageshack.us/i/dscf1285.jpg/