Pre det at 6k?
Discussion
On my recent trip to Spain (more on that later) I noticed a strange noise when hitting around 6k, which I can only assume is pinking. Sounded a bit like someone shaking a bag of popcorn. I was using 98 fuel but wondered if it was a combination of poor fuel and altitude. However, t took it for a blast on m11 at the weekend now I'm back and still have the same on a fresh tank of optimax.
Engine is a 2004 3.6 with 30k on the clock. No mods other than an ACT big bore exhaust (cats still in place). Anyone had similar problems?
Taking the car to Jason in two weeks for annual service so will get him to take a look.
Engine is a 2004 3.6 with 30k on the clock. No mods other than an ACT big bore exhaust (cats still in place). Anyone had similar problems?
Taking the car to Jason in two weeks for annual service so will get him to take a look.
RicSpeedSix said:
Jason said they run pretty close to the limit anyway. What's the likely course to rectify?
I've got a slight airbox leak at the moment so going to get that replaced with an ACT carbon one at the same time.
Ask Jason if he thinks it worthwhile replacing existing injectors with Bosch Green tops?. He does this as part of 4.3 rebuild as standard to flow more fuel.I've got a slight airbox leak at the moment so going to get that replaced with an ACT carbon one at the same time.
Agree, most likely cause was heat and altitude...and pushing car on limits!!
Nick
I was discussing AFR ratios and slightly lean running with Jason from TVR Power recently following a power run. No signs of detonation though.
Discussion and suggested way forward detailed at my blog here, based on this rolling road session
Summary was that stock injectors run close to max when new, but provide sufficient fuel. After a few years the flow rate can reduce, so AFR goes up at full throttle.
Changing for different injectors requires a remap (plus injector costs), so we were going to look at cleaning and flow-checking injectors the next time the car is in.
Discussion and suggested way forward detailed at my blog here, based on this rolling road session
Summary was that stock injectors run close to max when new, but provide sufficient fuel. After a few years the flow rate can reduce, so AFR goes up at full throttle.
Changing for different injectors requires a remap (plus injector costs), so we were going to look at cleaning and flow-checking injectors the next time the car is in.
In case anyone is interested in an update.
Turned out to be the engine loom. Took Jason and the guys a while to work out but diagnosis is that water has most likely got in over time. This has led to corrosion, which in turn has affected resistance, causing the ECU to mess up fueling and ignition advance.
The combination of new loom as well as new carbon airbox has completely transformed the car. Not only has pinking issue been resolved, but a long standing issue with roaming idle has also been resolved. The car has been completely transformed and now runs smoother than its ever done since I bought it. Additionally there is a definitive improvement in torque. Where before I had to drop a gear at low speed it's now happy without needing to do that.
Turned out to be the engine loom. Took Jason and the guys a while to work out but diagnosis is that water has most likely got in over time. This has led to corrosion, which in turn has affected resistance, causing the ECU to mess up fueling and ignition advance.
The combination of new loom as well as new carbon airbox has completely transformed the car. Not only has pinking issue been resolved, but a long standing issue with roaming idle has also been resolved. The car has been completely transformed and now runs smoother than its ever done since I bought it. Additionally there is a definitive improvement in torque. Where before I had to drop a gear at low speed it's now happy without needing to do that.
New loom. Was about £400 but that was included amongst a few other items.
Not being an expert but I'm guessing there could be a few issues for pre set. In my case the other symptom had been:
- inability to hold a steady idle, often hunting and revs rising, especially when hot
- unhappy to start of just the key alone, needed some throttle
- occasional hesitance on throttle
These have always seems to have been present to some degree although pinking issues were more recent. Up till now if had a number of things done including throttle bodies roller bearing mood done. Improved the situation but never been as smooth as it is now.
Not being an expert but I'm guessing there could be a few issues for pre set. In my case the other symptom had been:
- inability to hold a steady idle, often hunting and revs rising, especially when hot
- unhappy to start of just the key alone, needed some throttle
- occasional hesitance on throttle
These have always seems to have been present to some degree although pinking issues were more recent. Up till now if had a number of things done including throttle bodies roller bearing mood done. Improved the situation but never been as smooth as it is now.
Gassing Station | Speed Six Engine | Top of Page | What's New | My Stuff