Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Topics - demolite

Pages: [1]

Test Zone / Cheap V6 crank locking tool

« on: 04 October 2016, 19:31:44 »

Atleast some (I think all, but can someone confirm?) V6 engines have a crank sprocket where the bolt pattern is not uniform. This makes it impossible to install the aux belt pulley 180 degrees off.

See pic: (Upper thread hole is not in the center but about 4mm to the left of centerline)

Now I bought a crank locking tool set for doing the cambelt, and the crank tool didn't fit. Now I know why, here's the tools baseplate:

The hole which has the handscrew to screw to the upper sprocket thread is on the centerline of the tool! If it screws on, the tool is tilted and inaccurate. If you dont screw it on it won't go fully on the sprocket because the handscrew threads are in the way.

The tool can be used by removing the handscrew completely:

Needless to say, it has to be held on by hand when turning the crank.

Omega General Help / V6 cold start overfueling

« on: 11 September 2016, 13:46:52 »

Hi!

I've been tackling a problem with cold starts with my 2000 2.5 V6 (X25XE) facelift for some time now. Cold start here being any start at engine temperature of 30C or less. For the first 20-30 seconds the engine is overfueling and running rough and there's a strong smell of raw petrol in the cabin. This has happened on every cold start for atleast two months.

There are no fault codes, and the car runs fine for the rest of the day once the morning cold start is done with. There are no fuel leaks from the pipes, hoses, filter, pump assembly, injector rail, injectors, pressure test port or fuel pressure regulator. I ran the fuel pump for 30 minutes independent of engine with no fuel smell from anywhere (intake manifold was open to see injector leakage).

Typical start at ambient temperature 20C:
Upon starting, MID shows a fuel consumption of roughly 10 L/ hour which starts dropping slowly. Rpm is held at about 1300. About 3 seconds after start, engine starts running rough, fuel consumption is at 7-8 L/h. About 5 seconds after start strong fuel smell enters cabin, if car is creeping forward or stationary (smell coming from engine bay). It runs rough for about 20 seconds after this until the fuel consumption has dropped to about 4 L/h then suddenly engine smooths out. Fuel smell starts to fade and disappears in a matter of seconds. All is well for the rest of the day.

BUT, the engine smooths out instantly if the accellerator is pressed in any amount during rough running. Fuel consumption goes down when revs go up. Again if I let off the gas, the rough running returns. If I keep the revs at 1500 as soon as it starts for that 30 seconds there is no fuel smell or rough running at all.

Logs dont tell me much, but look at the spark advance when pressing and releasing the throttle .

Here is log and a video of a typical cold start.

Log:
https://www.dropbox.com/s/n0u55lr5wmsds29/cold_start_overfueling.csv?dl=1
Video: (sorry for bad audio, the blower vent was pointed to the microphone, and can't really re-shoot today)
https://youtu.be/FLPs0B-wbcw

Omega General Help / Rear multiram effect on idle

« on: 15 June 2016, 03:50:00 »

Hi, I'm tracking down vacuum leaks on my X25XE.

I'm in the process of opening up the plenum soon, but have a quick question for you V6 owners. In theory, on non-DBW engines, actuating the rear multiram (as in closing the valve) on idle should starve cylinder bank 1 of IAC air and thus make the idle very bad. On mine, turning the valve closed does absolutely nothing on idle. This leads me to believe that there is a bad leak on bank 1.

Could someone test their rear multiram and see what happens on idle?
This is to know if I should be extra rigorous on checking bank 1 when I open it up.

Thanks in advance!

Omega Electrical and Audio Help / Electrical ground fault and ground locations

« on: 24 April 2016, 13:01:58 »

I recently purchased a facelift Omega with the 2.5 V6 engine that had several garages look at it, change parts, rebuild the engine and finally deem it a lost cause. Repair costs were in the thousands.

The problem?

Bad ground to ECU which caused a voltage of 0.5 V at the ECU ground terminals. This caused the lambda signals to shift down by the same 0.5 V and show "lean" almost all the time resulting in an over rich fuel mixture and poor running. So beware, this is where the level of troubleshooting abilities have come to at some garages, even at the dealer!

I currently have additional ground wires running from the ECU to the engine and lambdas, but would like to find the "real problem". Being that the V6 engine bay is pretty full, I can't seem to locate all the main grounding points. I belive the (only?) chassis ground is below the battery as one of the battery negative cables runs there. The engine ground is located on the right side of the engine but where exactly and how can it be reached? And finally the culprit, the ECU ground, I'm thinking connected to engine but couldn't find it.

Thanks in advance!