Chasing the smooth running
01-31-19, 11:46 PM
#17
Pole Position
Thread Starter
Update
Ok so put a tankful of fuel through on a decent long distance run with some urban running as well and some interesting observations are coming to light.
Will keep you posted.
Ok so put a tankful of fuel through on a decent long distance run with some urban running as well and some interesting observations are coming to light.
- Fuel consumption is averaging around 10l/100 in hot weather - lots of full power aircon use so not too bad, definitely an improvement.
- The long term fuel trims have now moved back to the random patterns they were doing before the maf swap..... So there is definitely something else occurring in the system
- Drivability is better than before the new maf, although occasionally some hesitations present when giving it some acceleration-with-intent on certain occasions
Will keep you posted.
02-01-19, 11:38 AM
#18
Pole Position
Ls430 fuel consumption
Update
Ok so put a tankful of fuel through on a decent long distance run with some urban running as well and some interesting observations are coming to light.
Will keep you posted.
Ok so put a tankful of fuel through on a decent long distance run with some urban running as well and some interesting observations are coming to light.
- Fuel consumption is averaging around 10l/100 in hot weather - lots of full power aircon use so not too bad, definitely an improvement.
- The long term fuel trims have now moved back to the random patterns they were doing before the maf swap..... So there is definitely something else occurring in the system
- Drivability is better than before the new maf, although occasionally some hesitations present when giving it some acceleration-with-intent on certain occasions
Will keep you posted.
If steady highway driving you should experience 26 - 29 MPG...
Depending on kilometers driven, (and grade of fuel used) , the intake runners could have developed build-up., your fuel.injectors are in need of professional cleaning, and spark plugs are tired..
The best way to inspect for, and clean build-up is to remove intake manifold.
First remove the throttle body for cleaning,.
Do not operate manually by opening butterfly valve on throttle body..otherwise you might damage mechanism.
If lots of carbon build-up.there, then expect more on intake runners.
Last edited by YODAONE; 02-01-19 at 11:43 AM.
02-04-19, 08:58 PM
#19
Pole Position
Thread Starter
Thanks Yodaone,
Intake manifold off? Big job that one but you could well be right...I'll finish the baseline sensor renewal process first. I hope not to have to pull the manifold but hey if needs must.
So an update -
I ran the Subaru upper engine cleaner through. Was a much slower process than I had expected with the tubes filling hand having to wait for it to get into the intake manifold. Quite smoky too when the engine ran afterwards
Then I went on to fit the new spark plugs and ran into some interesting discoveries along the way:
The first discovery was that the number 8 plug well was drowning in engine oil! I am really amazed that the car didn't have a bad misfire (perhaps that explains the slight misfire in reverse gear?). Luckily I had a set of rocker cover gaskets on hand ready to install so rather than being a later job, became a today job. The rubbers sealing the plug tubes were all rock hard and cracking so good to replace. The outer gasket was strangely still in great condition which makes me think it has been replaced before/ relatively recently. The boots on the coil packs are all in great condition so I just dried it off the oil-drenched one and left them as they were.
Second discovery was the colouration of the old plugs - generally look to be burning pretty nicely except for the 2 closest to the firewall (Cyl #7) which were a lot sootier than the others. Is that normal with these engines? Could the injectors be more gummed up by being in a hotter part of the engine bay than the other cylinders?
As the battery had to come out to change the plugs on the left side the computer reset. So now the Long term fuel trims are back to behaving as when I first installed the MAF was new - ie pulling fuel at idle and 0% when driving.
It's running nicely but will post back after next tank of fuel is put through to see what the LTFT's read after a bit of distance is on it.
Last remaining step of this phase is the O2's. Might be a couple of weeks before I get the time to do those.
Cheers
Intake manifold off? Big job that one but you could well be right...I'll finish the baseline sensor renewal process first. I hope not to have to pull the manifold but hey if needs must.
So an update -
I ran the Subaru upper engine cleaner through. Was a much slower process than I had expected with the tubes filling hand having to wait for it to get into the intake manifold. Quite smoky too when the engine ran afterwards
Then I went on to fit the new spark plugs and ran into some interesting discoveries along the way:
The first discovery was that the number 8 plug well was drowning in engine oil! I am really amazed that the car didn't have a bad misfire (perhaps that explains the slight misfire in reverse gear?). Luckily I had a set of rocker cover gaskets on hand ready to install so rather than being a later job, became a today job. The rubbers sealing the plug tubes were all rock hard and cracking so good to replace. The outer gasket was strangely still in great condition which makes me think it has been replaced before/ relatively recently. The boots on the coil packs are all in great condition so I just dried it off the oil-drenched one and left them as they were.
Second discovery was the colouration of the old plugs - generally look to be burning pretty nicely except for the 2 closest to the firewall (Cyl #7) which were a lot sootier than the others. Is that normal with these engines? Could the injectors be more gummed up by being in a hotter part of the engine bay than the other cylinders?
As the battery had to come out to change the plugs on the left side the computer reset. So now the Long term fuel trims are back to behaving as when I first installed the MAF was new - ie pulling fuel at idle and 0% when driving.
It's running nicely but will post back after next tank of fuel is put through to see what the LTFT's read after a bit of distance is on it.
Last remaining step of this phase is the O2's. Might be a couple of weeks before I get the time to do those.
Cheers
05-18-19, 08:15 PM
#20
Pole Position
Thread Starter
After new injectors fitted in a highway cruise. Ltft's still fluctuating but overall closer to 0. Suspected cause of jumpy ltft- fuel pulse dampers
Quick update
Fitted
Set of flow matched injections. Old ones were quite dirty looking so can't be a bad thing. The car probably saw e10 at some point. So now at least I know the injectors are performing ideally.
Result after about 1000kms letting fuel trims time to learn:
Both banks have moved about 4% ltft closer to zero. But they are still in the negative and the fluctuating up and down quickly, occasional idle roughness, slight surging power in certain but not always situations.
Having seen the recent thread about pulsation dampers here, (never heard of pulse dampers before) who seem to have these exact symptoms. My hunch is these dampers have probably aged especially since suspected e10 use hardening rubber and therefore are not damping as designed anymore.
So my hypothesis is the ltft spikes are the computers way of trying to get on top of the fuel pulses
Have a set on order to test the theory.
On the plus side the occasional smelly catalytic converter smell has disappeared since the new injectors
Last edited by Aus430; 05-18-19 at 08:27 PM.
05-21-19, 10:17 AM
#21
Not necessarily, at heavy loads ( RPM) eggs smell can be cause by fuel which contains sulfur, engine running rich , bad fuel pressure regulator .. beside bad catalytic .
05-21-19, 01:27 PM
#22
Hi All,
So My LS430 which I grabbed a few months ago at a great price but 330,000km/200,000miles, a little rough in some places but overall solid, straight and no rust.
At the start I had to fix a few things - ie, got the ECU talking to the pc and elm32, replaced the nav DVD drive (ali express about $80), filter, oil, replaced all the old and hard rubber air hoses at the top of the engine and both VVT oil control solenoids, sprayed the MAF with cleaner and reset the yaw sensor.
Since then put a few thousand miles of it and generally running pretty well. however, fuel consumption is still on the high side (10-11l/100kms on long gentle highway runs) and there is some intermittent hesitations when accelerating from time to time. Looking at the ECU data the long term fuel trims are fluctuating a bit randomly from pulling fuel when cruising to adding fuel. Either way none of the sensors are obviously bad or throwing codes though there are some strange looking waveforms from time to time from the MAF and the o2 sensors. Occasionally smells like rotten eggs after 'giving it some beans'. So theory aside, my assumption is the o2's are getting lazy with age, the plugs could do with a refresh and the MAF is original and perhaps not at optimum performance anymore.
Coinciding with a trip to USA I decided to take advantage of some goodies from Rockauto to refresh some old parts, establish a baseline on the sensors and find the cause of the highish fuel consumption and hesitations. These include
*new PCV and seal,
*Denso MAF
*set of Denso TT plugs,
*set of Denso O2's
*New cabin filter - completely unrelated to the engine running but way cheaper in the USA than Australia.
In the name of a scientific approach, over the next few weeks, I am going to change one part type at a time and post back the results in case anyone else is having the same symptoms.
The first part changed is the PCV and seal. The old seal crumbled away (much like the other rubber intake hoses I replaced a couple of months ago) and the valve looks pretty cruddy anyway, Second off the rank will be the MAF, followed by the plugs and finishing with the O2's.
So My LS430 which I grabbed a few months ago at a great price but 330,000km/200,000miles, a little rough in some places but overall solid, straight and no rust.
At the start I had to fix a few things - ie, got the ECU talking to the pc and elm32, replaced the nav DVD drive (ali express about $80), filter, oil, replaced all the old and hard rubber air hoses at the top of the engine and both VVT oil control solenoids, sprayed the MAF with cleaner and reset the yaw sensor.
Since then put a few thousand miles of it and generally running pretty well. however, fuel consumption is still on the high side (10-11l/100kms on long gentle highway runs) and there is some intermittent hesitations when accelerating from time to time. Looking at the ECU data the long term fuel trims are fluctuating a bit randomly from pulling fuel when cruising to adding fuel. Either way none of the sensors are obviously bad or throwing codes though there are some strange looking waveforms from time to time from the MAF and the o2 sensors. Occasionally smells like rotten eggs after 'giving it some beans'. So theory aside, my assumption is the o2's are getting lazy with age, the plugs could do with a refresh and the MAF is original and perhaps not at optimum performance anymore.
Coinciding with a trip to USA I decided to take advantage of some goodies from Rockauto to refresh some old parts, establish a baseline on the sensors and find the cause of the highish fuel consumption and hesitations. These include
*new PCV and seal,
*Denso MAF
*set of Denso TT plugs,
*set of Denso O2's
*New cabin filter - completely unrelated to the engine running but way cheaper in the USA than Australia.
In the name of a scientific approach, over the next few weeks, I am going to change one part type at a time and post back the results in case anyone else is having the same symptoms.
The first part changed is the PCV and seal. The old seal crumbled away (much like the other rubber intake hoses I replaced a couple of months ago) and the valve looks pretty cruddy anyway, Second off the rank will be the MAF, followed by the plugs and finishing with the O2's.
05-22-19, 01:03 AM
#23
Pole Position
Thread Starter
It could be a bad regulator - and/or in this case possibly the Fuel Pulse Dampers. Main thoughts for it pointing to FPD is that the fuel for bank 2 the fuel rail has already passed 2 FPD's, and its LTFT is a lot more up and down that the Bank 1 LTFT which has the feed from fuel in. It is admittedly a hunch as I couldn't find any previously documented LTFT trace for dodgy Pulsation dampers. So will fit new ones when they arrive sometime in about 3 weeks and measure the difference. If anything just to rule them out, thought the symptoms I have closely match those listed in the recent FPD thread. If it isn't the FPD's, the next thing up the fuel line is the Regulator, though, if I do that it will be regulator and fuel filter at the same time given it is in the fuel tank.
And lastly if the cats are dead/dying, I want to make sure everything else is working tip top before installing and potentially ruining new cats without finding the cause.
The car was manufactured in Sept 2001. So I guess if you are in USA that is a 2002 model?
06-16-19, 12:08 AM
#25
Pole Position
Thread Starter
Well the new FPD's were installed this morning. Pretty easy job on bank 2. Bank one required moving the electrical harness out of the way to get access. I then went for a bit of a drive.
Result: it is now running buttery smooth, especially at idle. Can't really tell it's running at all without glancing at the tacho. Remarkable difference! Subtle but noticeable.
Ltft's are now read stable at idle both banks at 0%.
As soon as accelerator is pressed, both banks ltft drop into the negative like before (would this have something to do with the fuel pump 2 speed resistor circuit?) and then the ltfts jump around a bit like before but does seems less fluctuate less frequently.
Result: it is now running buttery smooth, especially at idle. Can't really tell it's running at all without glancing at the tacho. Remarkable difference! Subtle but noticeable.
Ltft's are now read stable at idle both banks at 0%.
As soon as accelerator is pressed, both banks ltft drop into the negative like before (would this have something to do with the fuel pump 2 speed resistor circuit?) and then the ltfts jump around a bit like before but does seems less fluctuate less frequently.
06-16-19, 08:15 AM
#27
Well the new FPD's were installed this morning. Pretty easy job on bank 2. Bank one required moving the electrical harness out of the way to get access. I then went for a bit of a drive.
Result: it is now running buttery smooth, especially at idle. Can't really tell it's running at all without glancing at the tacho. Remarkable difference! Subtle but noticeable.
Ltft's are now read stable at idle both banks at 0%.
As soon as accelerator is pressed, both banks ltft drop into the negative like before (would this have something to do with the fuel pump 2 speed resistor circuit?) and then the ltfts jump around a bit like before but does seems less fluctuate less frequently.
Result: it is now running buttery smooth, especially at idle. Can't really tell it's running at all without glancing at the tacho. Remarkable difference! Subtle but noticeable.
Ltft's are now read stable at idle both banks at 0%.
As soon as accelerator is pressed, both banks ltft drop into the negative like before (would this have something to do with the fuel pump 2 speed resistor circuit?) and then the ltfts jump around a bit like before but does seems less fluctuate less frequently.
Last edited by Bsavage; 06-16-19 at 09:29 AM.
06-16-19, 10:15 AM
#28
Well the new FPD's were installed this morning. Pretty easy job on bank 2. Bank one required moving the electrical harness out of the way to get access. I then went for a bit of a drive.
Result: it is now running buttery smooth, especially at idle. Can't really tell it's running at all without glancing at the tacho. Remarkable difference! Subtle but noticeable.
Ltft's are now read stable at idle both banks at 0%.
As soon as accelerator is pressed, both banks ltft drop into the negative like before (would this have something to do with the fuel pump 2 speed resistor circuit?) and then the ltfts jump around a bit like before but does seems less fluctuate less frequently.
Result: it is now running buttery smooth, especially at idle. Can't really tell it's running at all without glancing at the tacho. Remarkable difference! Subtle but noticeable.
Ltft's are now read stable at idle both banks at 0%.
As soon as accelerator is pressed, both banks ltft drop into the negative like before (would this have something to do with the fuel pump 2 speed resistor circuit?) and then the ltfts jump around a bit like before but does seems less fluctuate less frequently.
06-16-19, 04:46 PM
#29
Instructor
Hi All,
So My LS430 which I grabbed a few months ago at a great price but 330,000km/200,000miles, a little rough in some places but overall solid, straight and no rust.
At the start I had to fix a few things - ie, got the ECU talking to the pc and elm32, replaced the nav DVD drive (ali express about $80), filter, oil, replaced all the old and hard rubber air hoses at the top of the engine and both VVT oil control solenoids, sprayed the MAF with cleaner and reset the yaw sensor.
Since then put a few thousand miles of it and generally running pretty well. however, fuel consumption is still on the high side (10-11l/100kms on long gentle highway runs) and there is some intermittent hesitations when accelerating from time to time. Looking at the ECU data the long term fuel trims are fluctuating a bit randomly from pulling fuel when cruising to adding fuel. Either way none of the sensors are obviously bad or throwing codes though there are some strange looking waveforms from time to time from the MAF and the o2 sensors. Occasionally smells like rotten eggs after 'giving it some beans'. So theory aside, my assumption is the o2's are getting lazy with age, the plugs could do with a refresh and the MAF is original and perhaps not at optimum performance anymore.
Coinciding with a trip to USA I decided to take advantage of some goodies from Rockauto to refresh some old parts, establish a baseline on the sensors and find the cause of the highish fuel consumption and hesitations. These include
*new PCV and seal,
*Denso MAF
*set of Denso TT plugs,
*set of Denso O2's
*New cabin filter - completely unrelated to the engine running but way cheaper in the USA than Australia.
In the name of a scientific approach, over the next few weeks, I am going to change one part type at a time and post back the results in case anyone else is having the same symptoms.
The first part changed is the PCV and seal. The old seal crumbled away (much like the other rubber intake hoses I replaced a couple of months ago) and the valve looks pretty cruddy anyway, Second off the rank will be the MAF, followed by the plugs and finishing with the O2's.
So My LS430 which I grabbed a few months ago at a great price but 330,000km/200,000miles, a little rough in some places but overall solid, straight and no rust.
At the start I had to fix a few things - ie, got the ECU talking to the pc and elm32, replaced the nav DVD drive (ali express about $80), filter, oil, replaced all the old and hard rubber air hoses at the top of the engine and both VVT oil control solenoids, sprayed the MAF with cleaner and reset the yaw sensor.
Since then put a few thousand miles of it and generally running pretty well. however, fuel consumption is still on the high side (10-11l/100kms on long gentle highway runs) and there is some intermittent hesitations when accelerating from time to time. Looking at the ECU data the long term fuel trims are fluctuating a bit randomly from pulling fuel when cruising to adding fuel. Either way none of the sensors are obviously bad or throwing codes though there are some strange looking waveforms from time to time from the MAF and the o2 sensors. Occasionally smells like rotten eggs after 'giving it some beans'. So theory aside, my assumption is the o2's are getting lazy with age, the plugs could do with a refresh and the MAF is original and perhaps not at optimum performance anymore.
Coinciding with a trip to USA I decided to take advantage of some goodies from Rockauto to refresh some old parts, establish a baseline on the sensors and find the cause of the highish fuel consumption and hesitations. These include
*new PCV and seal,
*Denso MAF
*set of Denso TT plugs,
*set of Denso O2's
*New cabin filter - completely unrelated to the engine running but way cheaper in the USA than Australia.
In the name of a scientific approach, over the next few weeks, I am going to change one part type at a time and post back the results in case anyone else is having the same symptoms.
The first part changed is the PCV and seal. The old seal crumbled away (much like the other rubber intake hoses I replaced a couple of months ago) and the valve looks pretty cruddy anyway, Second off the rank will be the MAF, followed by the plugs and finishing with the O2's.
