vlad01 wrote:It's hard to know what it actually is or if it's a multitude of things all contributing. My old VP vacationer used to get about 7L/100 but as the engine got a lot of Ks on it it increased to about 10-11L/100 by the time it had 400K on the clock. Interestingly that was even with perfect tune and knock retard disabled.
But one thing I did notice was severe lifter rattle at certain rpms, they were bleeding down so perhaps I was loosing valve lift and timing. The engine was a little down on power from 90K on the clock when I first installed it but not a massive amount, maybe 10-20%?
My new VP auto with 120k stock gets way better economy than my old shitbox VP with perfect tune, knock disabled and manual, with lean cruise, but the engine had a very hard life. Overheated badly by my nephew, drove it 40km with no coolant and seized it 6 times on the way home and the valve springs are weak I think as it struggles to get power over 4k rpm, rolls over a lot compared to my other cars. Now it's consuming coolant so it's on it's last legs. The economy has deteriorated to about 12L/100 at the moment.
Vlad01, that is interesting and could be a vital thing for me. Though I am just guessing as i wouldn't know how i can test for weak lifters? But I replaced the lifters in this current refurbished motor, so presume they are ok?
My issue is, if I think back to my older cars with carby systems....yes i am that old . Well with those engines, using vacuum gauges, timing lights, dwell meters, I could confirm that things like mechanical issues were the cause or not. Using same tools today on this car, the vacuum gauge shows me signs of either poor mixture or spark timing. Nothing like valve springs weak or late vales timing etc. So hence why I am at a bit of a loss. Also, back in the days, I had funds to throw parts after part to resolve issues, I can't do that these days at the moment.
Raise the rpm to about 3k and it should sound like a heap of marbles bouncing on a hard surface. It's very obvious.
That's probably a result of me winding the engine out to the limiter over and over for 300k. I am sure you don't drive like that and yours being a late engine will have 2nd or 3rd gen lifters in it which are much more tolerate than my 1st gen lifters.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
JohnDee68 wrote:Now you have me thinking, i may be confusing the exhaust and inlet valves. I am not sure what i said previously, but i am pretty confident the increased size valve on the current engine were the inlet valves. Looking back over pictures at the time of the refurbishment, I cant see what is the inlet or the exhaust. So no, i cant be 100% sure what was what now. Though I am pretty sure it was a larger inlet valves on the current engine.
valves.jpg
Thanks quipt4it,
Now I cant be 100% sure that it is or isn't an inlet valve, but I am pretty confident (from memory) that the loose valve was an inlet vlave from the VT head at the time, placed upside down on the Inlet valve of the VY head. At the time i recalled thinking, 1. oh, is this going to be an issue. & 2. What car had this actually come out of. But no I can't be 100% certain.
I have done (presumably correct Bin files ect. being used) the Bin flashing but with my doubts of some accuracy to some address mapping. I get what seems to be reporting back through Tunerpro logging's a working motor with nothing out of the specs. However, I don't believe the knocks nor some values for some addresses are even possibly correct. When I compare bin files of others to the bin file from my very first original PCM, some values are way out of range that one would be expecting in those areas. Without having knowledge to the exact address locations of what data is held where in the PCM, I can't be sure what is actually right as to what it is telling me it is.
I might try your suggested knock turn off method after next weekend (as need the car operational for next 9 days). Though i don't feel there is an actual knocking happening in the motor. But that's not to say that the PCM isn't getting a false or misleading reading to the contrary and adjusting accordingly.
Charlescrown wrote:I know what your saying but that's not the case the 0.5 volts is determined from an average of the o2 sensor swinging around. There are so many variables that take place it's impossible for the system to supply and burn a perfect mix hence the role of the O2 sensor. It's the ECU responding to changes from the O2 sensor that you see taking place. I found out about 15 years ago that as they get old they become lazy and the outcome is slow to react to change. The vehicle was a Holden with Delco and it had been to several workshops and had quiet a few sets of plugs, leads and the injectors replaced to fix a high fuel consumption problem. This was over a two year period and nobody thought to look at how active the o2 sensors were because there was no fault codes displayed. It was then that a company called Coda got the car and straight away found the problem.
On further review of a few logs i have done with the TunerPro over the years, I notice that the O2 sensors at points do read a more stable mid range minimal fluctuation as I would expect. However, it seems that it does so in open loop mode? Is it common for the car to go in and out of open and closed loop modes? Does it go in to Open loop modes when there are too much variations for the STFT to make up so it defaults back to a preset type (open loop) fuel mix? Or is it just when the AFR target isn't on spec?
Did you manage to find out what signs on the O2 readings showed that the O2 sensors were lazy? I feel mine are responding very quickly from what I can tell.
JohnDee68 wrote:...Now I cant be 100% sure that it is or isn't an inlet valve, but I am pretty confident (from memory) that the loose valve was an inlet vlave from the VT head at the time, placed upside down on the Inlet valve of the VY head. At the time i recalled thinking, 1. oh, is this going to be an issue. & 2. What car had this actually come out of. But no I can't be 100% certain...
vlad01 wrote:It's hard to know what it actually is or if it's a multitude of things all contributing. My old VP vacationer used to get about 7L/100 but as the engine got a lot of Ks on it it increased to about 10-11L/100 by the time it had 400K on the clock. Interestingly that was even with perfect tune and knock retard disabled.
But one thing I did notice was severe lifter rattle at certain rpms, they were bleeding down so perhaps I was loosing valve lift and timing. The engine was a little down on power from 90K on the clock when I first installed it but not a massive amount, maybe 10-20%?
My new VP auto with 120k stock gets way better economy than my old shitbox VP with perfect tune, knock disabled and manual, with lean cruise, but the engine had a very hard life. Overheated badly by my nephew, drove it 40km with no coolant and seized it 6 times on the way home and the valve springs are weak I think as it struggles to get power over 4k rpm, rolls over a lot compared to my other cars. Now it's consuming coolant so it's on it's last legs. The economy has deteriorated to about 12L/100 at the moment.
Vlad01, that is interesting and could be a vital thing for me. Though I am just guessing as i wouldn't know how i can test for weak lifters? But I replaced the lifters in this current refurbished motor, so presume they are ok?
My issue is, if I think back to my older cars with carby systems....yes i am that old . Well with those engines, using vacuum gauges, timing lights, dwell meters, I could confirm that things like mechanical issues were the cause or not. Using same tools today on this car, the vacuum gauge shows me signs of either poor mixture or spark timing. Nothing like valve springs weak or late vales timing etc. So hence why I am at a bit of a loss. Also, back in the days, I had funds to throw parts after part to resolve issues, I can't do that these days at the moment.
Raise the rpm to about 3k and it should sound like a heap of marbles bouncing on a hard surface. It's very obvious.
That's probably a result of me winding the engine out to the limiter over and over for 300k. I am sure you don't drive like that and yours being a late engine will have 2nd or 3rd gen lifters in it which are much more tolerate than my 1st gen lifters.
Well, I have pushed my engine more of late (stationary) in a process of testing for issues relating to the excess fuel usage, but no I wouldn't drive it like that usually. That's what sort of annoys me with this issue. To me and others, it seems to be a perfectly, well running motor. No audible knocking, no pinging, no rough idling, no misfires or any unexpected noises, No brake binding, no wind or friction drag, all sensors test and report back to software as ok. All i can see is that the economy is shit, and there is a lack of power. i run a calculation today of the fuel usages. It seems I am using up to 25 liters more per tank of fuel than what it should. So quite a notable and costly amount of fuel excess.
I am having my brain go through many options and possibilities to try resolving my issues. Can I have some feedback on these thoughts please guys?
1. Presuming that the Vx and Vy motors are identical except the Inlet valve sizes not anything like Cam timing being any difference. Would the PCMs be the same also and if so, would a VY bin file be correct to compare settings to my VX ? As there are some that seem to line up, others couldn't be any further out of possibilities. Here is a screenshot of just some.
The car when started is in open loop mode. Once it reaches a set temp (30°C IIRC) it goes into closed loop mode when driving. If you increase the throttle a small amount it should stay in closed loop but give it a decent increase in TPS and the car goes into Open loop mode for PE (power enrichment). The engine will also go into lean cruise/open loop when cruising down the motorway and there is also open loop idle.
As mentioned earlier, load fresh ADX, XDF and bin files and start afresh.
Looks like you may have done something wrong when altering your XDF parameters.
VX and VY are listed as separate zip files: viewtopic.php?f=27&t=2518
They also use different XDF's, so you can't directly do a 'Compare Bin".
Download the Memcal ID tool: viewtopic.php?f=3&t=905
This is a good way to verify correct OS and any differences between model variants etc.
The FAQ section, top right of screen is a mine of info. The search bar can also be a great help.
. Well with those engines, using vacuum gauges, timing lights, dwell meters, I could confirm that things like mechanical issues were the cause or not. Using same tools today on this car, the vacuum gauge shows me signs of either poor mixture or spark timing. Nothing like valve springs weak or late vales timing etc. So hence why I am at a bit of a loss. Also, back in the days, I had funds to throw parts after part to resolve issues, I can't do that these days at the moment.