I advanced my perhaps worn pump and it made a noticeable improvement in smoke and driveability. If i loosen injector lines and nudgit ahead some more what can I expect from experience doing this? What are the risks? How would i know if the retarder innoperative as someone assertd could be the case on another thread?
What to expect advancing timing more
- Thread starter Vern
- Start date
The_Josh_Bear
Full Access Member
I dont know what that means...but advancing the pump will never make the "advance piston" inoperative. Its job is actually to retard timing so I've no idea why it's called the advance piston, BTW.
Advancing is good if it needs it. You can expect cleaned up exhaust, a stronger running engine, better MPGs and cleaner starts.
The risks aren't much, really the worst thing you will get is too advanced will eat your glow plugs over time. But it's pretty hard to get it *that* advanced.
The easiest thing to do by ear is time it so that when the timing advance and high idle circuit drops down, the strong "powerstroke rattle" goes away(not really gone but less piercing). This will get you in the ballpark. Timing equipment is best.
Thanks, Josh
Well the piston is the advance that is caused by pump body pressure but the retarder as I might as well call it acts on the advance piston via the accelerator shaft linkage. so its like supposed to retard or keep the pump from advancing under light loads. I was wondering what one person bravely asserted that someones light load timer thing was just bad. Like it would just "go".
I think it needs it. it seems like a reasonably healthy engine and doesn't need to smoke so much. Perhaps the fuel screw is spun up.
Well the piston is the advance that is caused by pump body pressure but the retarder as I might as well call it acts on the advance piston via the accelerator shaft linkage. so its like supposed to retard or keep the pump from advancing under light loads. I was wondering what one person bravely asserted that someones light load timer thing was just bad. Like it would just "go".
I think it needs it. it seems like a reasonably healthy engine and doesn't need to smoke so much. Perhaps the fuel screw is spun up.
The_Josh_Bear
Full Access Member
Ok so you've got the right idea for sure. But you should not worry about that mechanism failing from advancing or retarding the IP. You wont hurt/bother/affect the face cam or advance piston at all. Some people have broken them, sure, but the only times I've heard of it is with an internally sticking advance plunger(from sitting around and most likely having water contamination), but obviously yours is working fine since its driving around currently.
If you want to be extra sure then fill up your fuel filter with ATF, run the engine for 20 or 30 seconds and leave it that way overnight or longer. ATF has awesome detergents and lubricants and will help the injectors and IP be happy and moving freely. Bear in mind that doing this will make the engine run "quieter" and so until that tank of fuel is empty timing it by ear will be weird.
I just did this last weekend and I couldn't believe how quiet my engine was with just half a quart of ATF in 8-10 gallons of fuel. Switched to the rear tank later and the rattle came right back.
If you want to be extra sure then fill up your fuel filter with ATF, run the engine for 20 or 30 seconds and leave it that way overnight or longer. ATF has awesome detergents and lubricants and will help the injectors and IP be happy and moving freely. Bear in mind that doing this will make the engine run "quieter" and so until that tank of fuel is empty timing it by ear will be weird.
I just did this last weekend and I couldn't believe how quiet my engine was with just half a quart of ATF in 8-10 gallons of fuel. Switched to the rear tank later and the rattle came right back.
Macrobb
Full Access Member
The lever you are speaking about is called the "light load advance cam". At idle, the lever is fully out at the bottom which is the most advanced position. As you add more throttle, it pushes it in, which retards the motor. So idle = most advanced, WOT = most retarded... at least with that cam/lever. The actual timing numbers vary with fuel supply pressure, RPM(internal pump pressure), throttle/used fuel, etc.
It clearly neaded it. I've put about 16hrs of driving on the truck towing 5500lbs after advancing the timing. now i do not notice a light load smoke. Cleaner starting. It rolls smoke deeper in the pedal. Fuel economy is noticeably improved and it runs cooler. Something like 16l/100km. Pretty impressive.
I did not mess with the light load advance.
How does a pump get this way?
I've run atf in the fuel for the very reasons you mention, the josh bear. I have not put it in the filter befor. I put diesel kleen in the filter the other filter change and darn i had a hard time starting after that. Speaking of switching tanks, anybody have this power surge phenomenon when the frint tank gets to the bottom?
I did not mess with the light load advance.
How does a pump get this way?
I've run atf in the fuel for the very reasons you mention, the josh bear. I have not put it in the filter befor. I put diesel kleen in the filter the other filter change and darn i had a hard time starting after that. Speaking of switching tanks, anybody have this power surge phenomenon when the frint tank gets to the bottom?
The_Josh_Bear
Full Access Member
That's good news, glad to hear the advancing worked well.
The pump got that way by old age or simply not being timed once it was installed. Or being installed with new injectors.
The ATF or diesel clean treatment was more of a suggestion for cleaning out the IP and injectors, they will be good to go for a while now. Some guys use a fuel treatment all the time, some almost never, there's a big variation.
If you have access to B5 biodiesel its lubricity is better than anything you can buy off the shelf anyway and is cheaper usually.
There's a member on FTE that has 5ish fleet IDIs since they were new. Never uses fuel treatment except for ATF a few times a year in the filter and gets 150k on the IPs and injectors. Every engine went/is over 300k too. So fuel additives are good but not mandatory, unless you have poor fuel somehow.
The power surge you get is from sucking some air in that tank through the IP. The air makes the IP run WOT or close to it even though you are just cruising with the pedal.
Other, smarter guys could tell you the why(cause I dont know), but that's the short version.
The pump got that way by old age or simply not being timed once it was installed. Or being installed with new injectors.
The ATF or diesel clean treatment was more of a suggestion for cleaning out the IP and injectors, they will be good to go for a while now. Some guys use a fuel treatment all the time, some almost never, there's a big variation.
If you have access to B5 biodiesel its lubricity is better than anything you can buy off the shelf anyway and is cheaper usually.
There's a member on FTE that has 5ish fleet IDIs since they were new. Never uses fuel treatment except for ATF a few times a year in the filter and gets 150k on the IPs and injectors. Every engine went/is over 300k too. So fuel additives are good but not mandatory, unless you have poor fuel somehow.
The power surge you get is from sucking some air in that tank through the IP. The air makes the IP run WOT or close to it even though you are just cruising with the pedal.
Other, smarter guys could tell you the why(cause I dont know), but that's the short version.
The_Josh_Bear
Full Access Member
Hey Vern, one cool trick Macrobb has posted before is to use the Allen screw in the bottom of the above mentioned light load advance lever to tweak timing settings without having to rotate the whole pump. This is for small adjustments once you are close to your desired timing.
Just screw the Allen in 1/2 turn or full turn to retard it a little, or back it off to advance it a little. I wish I could say "one turn equals 1 degree of timing" but I've never measured it. One turn is probably 1/2 degree of timing if I were to guess...dont quote me on that!
Anyhow its terribly handy once you sacrifice an Allen wrench to the cause. In order to adjust it on the pump you'll have to cut one down to a nub, but it's awesome for those seasonal timing changes, and fine tuning timing that's close.
Hey Vern, one cool trick Macrobb has posted before is to use the Allen screw in the bottom of the above mentioned light load advance lever to tweak timing settings without having to rotate the whole pump. This is for small adjustments once you are close to your desired timing.
Just screw the Allen in 1/2 turn or full turn to retard it a little, or back it off to advance it a little. I wish I could say "one turn equals 1 degree of timing" but I've never measured it. One turn is probably 1/2 degree of timing if I were to guess...dont quote me on that!
Anyhow its terribly handy once you sacrifice an Allen wrench to the cause. In order to adjust it on the pump you'll have to cut one down to a nub, but it's awesome for those seasonal timing changes, and fine tuning timing that's close.
That’s not what that adjustment is for, please don’t change your timing this way. You aren’t changing your static timing with this adjustment, you are changing the gain that the face plate has on the timing curve so you are changing timing for only around 60% of the rpm range when the cam pin is actually acting on the cam.
The_Josh_Bear
Full Access Member
I'm not sure I follow but I'll defer to your understanding. Like I said I haven't put my meter on it but the adjustments using this method seem very linear and just like rotating the pump to me.
Macrobb
Full Access Member
In my experience, going "in" from stock(to retard) is relatively linear(on a WORKING IP), going "out" is not - it hits a wall and won't advance any more.
Also, pretty sure the pin is acting on the cam 100% of the time - yes, it's only 'varying' during the cam-lift portion; before and after that, it's a "flat" profile" - but it still affects the timing the same way at any throttle position.
Also, something of note:
In my mind, if you are using a new IP, something that's actually to spec? Get it timed, go with the 'correct' adjustments and call it good.
Once you are using a worn out P.O.S pump that's been in use for years? Well, make it work, any way you can. That's when some of these other adjustments come into play:
------------
I just shoved an old, worn pump on my '93, so I could take my R&D pump for the 'big turbo' build. The used pump I *wanted* to use has issues(end play on the input shaft, missing bushing?), so instead I'm using a pump that came with a JY '93 motor. When I got it originally, it smoked above idle and was really retarded.
Currently, I've got it adjusted for DDing it, so it actually needed to work well.
The problem was, as I found out, the RPM-advance isn't working. At all. So, at idle it would be advanced, at 3K it would be smoking and missing.
In order to 'fix' that, I have:
1. IP gear is "skipped" 1 tooth forward(6-7 degrees of advance at nominal IP rotation).
2. IP is cocked about 1 degree retarded. (these two measures give me about 6 more degrees of advance at 3K, getting it into 'slightly retarded, but not smoking white')
3. Light load advance cam is pushed so far forward that it goes to 'full retard' at just off idle. (With the 'base timing' advanced so much, idle was now extremely advanced. "locking out" the added advance gets it back to a reasonable level).
This ended up producing a reasonable working timing set. Is it as good as a new IP? Heck no!
But I need the truck running good and don't have $500+ to spend on a new IP.
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That is the case where it pays to mess around, see how it feels and drives at various RPMs and adjust from there. When you need a new IP, but don't want to buy one. You pretty much have nothing to lose by messing with it.
Oh, and speaking of which... Everyone says that advanced timing will kill glow plugs almost instantly. Well, during my test drives with said worn IP, I had it *extremely* advanced down low at first. Clatter clatter clatter. And... all of my glow plugs are still fine. No short-cycling. 'Course, I do have ZD-9s.
Also, pretty sure the pin is acting on the cam 100% of the time - yes, it's only 'varying' during the cam-lift portion; before and after that, it's a "flat" profile" - but it still affects the timing the same way at any throttle position.
Also, something of note:
In my mind, if you are using a new IP, something that's actually to spec? Get it timed, go with the 'correct' adjustments and call it good.
Once you are using a worn out P.O.S pump that's been in use for years? Well, make it work, any way you can. That's when some of these other adjustments come into play:
------------
I just shoved an old, worn pump on my '93, so I could take my R&D pump for the 'big turbo' build. The used pump I *wanted* to use has issues(end play on the input shaft, missing bushing?), so instead I'm using a pump that came with a JY '93 motor. When I got it originally, it smoked above idle and was really retarded.
Currently, I've got it adjusted for DDing it, so it actually needed to work well.
The problem was, as I found out, the RPM-advance isn't working. At all. So, at idle it would be advanced, at 3K it would be smoking and missing.
In order to 'fix' that, I have:
1. IP gear is "skipped" 1 tooth forward(6-7 degrees of advance at nominal IP rotation).
2. IP is cocked about 1 degree retarded. (these two measures give me about 6 more degrees of advance at 3K, getting it into 'slightly retarded, but not smoking white')
3. Light load advance cam is pushed so far forward that it goes to 'full retard' at just off idle. (With the 'base timing' advanced so much, idle was now extremely advanced. "locking out" the added advance gets it back to a reasonable level).
This ended up producing a reasonable working timing set. Is it as good as a new IP? Heck no!
But I need the truck running good and don't have $500+ to spend on a new IP.
------
That is the case where it pays to mess around, see how it feels and drives at various RPMs and adjust from there. When you need a new IP, but don't want to buy one. You pretty much have nothing to lose by messing with it.
Oh, and speaking of which... Everyone says that advanced timing will kill glow plugs almost instantly. Well, during my test drives with said worn IP, I had it *extremely* advanced down low at first. Clatter clatter clatter. And... all of my glow plugs are still fine. No short-cycling. 'Course, I do have ZD-9s.
IDIBRONCO
IDIBRONCO
That's funny, some of the people I know go full retard when they're going WFO!
