XR8 series 3 issues - Page 2

SVT8 · 17-04-2012, 02:31 PM

First thing i would do is scan all codes. It will tell you if its a sensor/computer issue or weather its something else mechanical related.

If scan comes back ok, then you can narrow your search down to something fuel or spark related.

madmelon · 17-04-2012, 03:27 PM

Just confirmed with Ford, no fault codes. Waiting on their sparky to start looking at stuff.

madmelon · 18-04-2012, 08:26 PM

"Checked and unable to reproduce concern at this time"

Honestly, if a customer says they've had a specific problem for 6 months under these exact conditions, does it really matter if a mechanic can't reproduce them? What's wrong with investigating potential causes based on what the customer says, instead of treading the customer like a complete moron and insisting on "replicating the concern" before doing any actual work. Unbelievable.

**Peuty** · 18-04-2012, 08:57 PM

Quote:

Originally Posted by madmelon

"Checked and unable to reproduce concern at this time"

Honestly, if a customer says they've had a specific problem for 6 months under these exact conditions, does it really matter if a mechanic can't reproduce them? What's wrong with investigating potential causes based on what the customer says, instead of treading the customer like a complete moron and insisting on "replicating the concern" before doing any actual work. Unbelievable.

Because the bill could stack up into the thousands with no real diagnosis. Then you as the customer would be upset at having to pay money for no result!!

**Whoosha** · 18-04-2012, 09:04 PM

Was about to say what Peuty said , the thing is these cars are getting old and things ware and go wrong my 220 has pinged since new with the slightest hint of crook fuel even with a aftermarket tune in would do the same . Since having the heads off and a light machine it just pushes harder than ever witn no sign of pinging. It could be 1 of a hundred things in a old motor from carbon build up to a compressed valve spring, to something simple that no one has stumbled onto yet.. I would nearly be tempted to get a full tune with new box and start again atleast then the tuner can pull some timing out if needed , but yeah I feel your frustration

madmelon · 18-04-2012, 09:28 PM

Ok so lets not get carried away here- there are a few simple things that could easily be checked that wouldn't cost a fortune and may give some answers. Fuel pressure, MAF behaviour, fuel flow from return line, etc. Previously suggested on here and elsewhere.

Noddy · 14-08-2012, 10:44 PM

My auiii xr8 has the same issues, pinging on 98. What should the fuel pressure measure?

madmelon · 15-08-2012, 01:47 PM

Quote:

Originally Posted by Noddy

My auiii xr8 has the same issues, pinging on 98. What should the fuel pressure measure?

I'm not sure but my issue was resolved when I had it tuned by Spirro at Autotech. I picked up 15kW atw and haven't heard it ping since. Was mega rich (~10.0:1 AFR) and he suggested the resulting excessive carbon buildup could have been causing the problem under high load.

**auIILTD** · 15-08-2012, 04:43 PM

Quote:

Originally Posted by madmelon

I'm not sure but my issue was resolved when I had it tuned by Spirro at Autotech. I picked up 15kW atw and haven't heard it ping since. Was mega rich (~10.0:1 AFR) and he suggested the resulting excessive carbon buildup could have been causing the problem under high load.

Yep! That is rich!

What was the economy like?

BOTTLEDUP · 15-08-2012, 06:47 PM

Poor chamber design of the GT40P head doesn't really help things either.

Unleaded fuels are very sensitive to the quench area of the head, you need to have the pistons as close to 0.000" deck as you can, and even above the deck if possible. Using a true flat top piston also helps.

I've seen plenty of 347s built the 'old school' way (pistons 0.010-0.030" down the bore) and they detonate even with 9:1 compression. In most cases its the poor combustion area which is the source of the problem.

madmelon · 16-08-2012, 10:14 AM

Quote:

Originally Posted by auIILTD

Yep! That is rich!

What was the economy like?

The economy was generally excellent to be honest, especially considering how I drive it. Until a year ago, it was 2 hours each day in Sydney traffic to and from work, where it would get 11.5-12.5L/100km. This is the same or better economy I get out of my BF XR6 with ZF 6 speed that I now do that same trip in every week day.

Highway cruising was pretty good- on the way back from Adelaide when I bought it we got to ~7.8L/100km. Sady, I haven't been able to repeat that on trips to/from Wollongong.

GK · 16-08-2012, 10:26 AM

Quote:

Originally Posted by madmelon

The economy was generally excellent to be honest, especially considering how I drive it. Until a year ago, it was 2 hours each day in Sydney traffic to and from work, where it would get 11.5-12.5L/100km. This is the same or better economy I get out of my BF XR6 with ZF 6 speed that I now do that same trip in every week day.

Highway cruising was pretty good- on the way back from Adelaide when I bought it we got to ~7.8L/100km. Sady, I haven't been able to repeat that on trips to/from Wollongong.

That's great economy.

Makes me long for a Windsor all the more!

GK