01 lb7
Registered User
I just installed bb codes in my truck and I was wondering if the timing has to be reset with them, I tried searching and can't find the results I'm looking for
injector install questions
- Thread starter 01 lb7
- Start date
vegas39
Full Access Member
Yes, your timing should be reset as new injectors usually pop at a higher pressure than the old worn out ones.
01 lb7
Registered User
Ok I figured as much. What s the best way to time it by ear. And would timing cause it to run a little rough at 2k? And it blue smokes a bit too. All this at a stand still as it hasn't been out of the shop
TWeatherford
Full Access Member
I'm fairly sure that timing meters using the pulse method measure the pressure spike in the injection line which the injection pump delivers to fire the injector. Therefore I don't see how the timing meter would be able to tell a lick of difference between timing with new vs old injectors, even if they pop at different pressures, because the surge of pressure happens at the same time regardless of what kind of injector is attached to the end of it. The timing meter doesn't know when the injector opens, only when the surge of pressure happens in relation to crankshaft location. Unless it somehow senses when the pressure surges then drops off, which would actually measure when the fuel is injected, which would change with new or old injectors.
I would love for someone to measure timing with old, worn out injectors and then with new, and see if timing changes. I doubt it would be much if any measurable difference. I know that there has been speculation that changing feed pressure to the IP changes timing, however our member RLDSL did a test where he changed the pressure from low to high end of the range and checked timing, and it didn't budge.
I would love for someone to measure timing with old, worn out injectors and then with new, and see if timing changes. I doubt it would be much if any measurable difference. I know that there has been speculation that changing feed pressure to the IP changes timing, however our member RLDSL did a test where he changed the pressure from low to high end of the range and checked timing, and it didn't budge.
01 lb7
Registered User
Well going from code g to bb's made me think so cause they allow more fuel don't they.
icanfixall
Official GMM hand model
The above posting is not completely correct but close. This is what happens when you change either the injectors or the injection pump with timing. As the original poster tells us he changed from G codes that pop at 2200 or 2300 lbs to Bb codes that pop at a known 1850 lbs. So the timing is now advanced way more than it was because the pop pressure is now lower. Now change a pump and not injectors your timing can be anywhere on the timing issue because you don't know what the pump was able to put out in pressure. Now as the po states about the injector change.. Whats the pump able to pump now. Is it borderline or able to still do its job properly....
When these engines are up running the injector lines are pumped up to a pressure just below pop pressure so they are "fully loaded". When the pump internals rotate around to the next injector there is a push of fuel that pops open the injector. The injector line pressure does not decay between injector pops. So in closeing any changes in the pump or injectors will change the timing. To have a properly working fuel system you need to know the condition of the sub systems like filter, injection pump and injectors. Hope this adds to the collective knowledge and if I missed something please post it. I don't remember everything nor an I an expert on anything....
01 lb7
Registered User
That's good info man it really explained what and why it needs to be adjusted. Now what do I listen for to time it by ear and how do I adjust it
TWeatherford
Full Access Member
ok, cool. Learn something new everyday. I still would love to do a test to see how much it changes with an injector change. My guess is not much at all, and if your timing was right before the swap my guess is that timing it by ear would only get it further away from correct.
01 lb7
Registered User
well from what was just said it cant be correct because the fuel is being injected too soon, so i need to retard the timing but i don't have the timing tools, and i need to get it close cause i dont see it running worth crap on the road once i finish getting it out of the shop, it idles ok, its a little rough, but just slightly, and when you rev it to 2k it runs pretty rough. so i know i have to take the gear cover off the front but then i dont know exactly what to do, i have an idea but not a confirmed story.
redneckaggie
rebel w/o a cause
what tweathorford is saying is that timing by ear is just a guess. your g codes were not popping at that high of pressures unless they were brand new. You also do not know how worn the injection pump is. As the pump and injectors wear they retard the timing. you dont have to remove front cover to time just loosen three bolts on the firewall side of the injection pump flange. twist pump towards drivers to retard, passengers to advance. too much advance will cause the truck to rattle like a psd engine. I set mine by ear to where when the timing advance and high idle was engaged it rattled almost to a psd level.
01 lb7
Registered User
i know timing by ear is a guess, but i need it driveable then i can take it to get it timed properly or give me time to buy the tools
OK first of all.... STOP! Do not pass go. We have some things to discuss here before you touch anything else. Please answer the following questions.
Why did you change your injectors?
What injectors did you install? Specifically from who?
What did your old injectors look like when you took them out.
When was your timing last set?
Did you have your old ones pop tested?
Did you have your new ones pop tested?
If the answer to the last two questions are both "No". Then all you have done is exchanged one unknown for another. It doesn't surprise me that your still complaining of rough running and blue smoke.
Blue smoke at idle is a leaking injector!
Rough running can be a worn out pump. How many miles are on it?
Don't move your pump! You can play with the timing a little by manually actuating the cold idle advance. That's a good way to advance the pump by 1.5 degrees or so.
Why did you change your injectors?
What injectors did you install? Specifically from who?
What did your old injectors look like when you took them out.
When was your timing last set?
Did you have your old ones pop tested?
Did you have your new ones pop tested?
If the answer to the last two questions are both "No". Then all you have done is exchanged one unknown for another. It doesn't surprise me that your still complaining of rough running and blue smoke.
Blue smoke at idle is a leaking injector!
Rough running can be a worn out pump. How many miles are on it?
Don't move your pump! You can play with the timing a little by manually actuating the cold idle advance. That's a good way to advance the pump by 1.5 degrees or so.
01 lb7
Registered User
because they were leaking
remans from pensacola
old
no idea
no
no
but i wasnt complaining of blue smoke and roughness before i changed them. i replaced them because one or more was leaking and evertime i started it after it sit for more than an hour or two and it would miss and blow white puffs then clear up, and they had never ever been changed, the dates were 7/93 on em! what exactly are you looking for on the ' how did they look ' part? now it is constant blue and runs rough at 2k, but it could possibly still have some air bubbles it hasn't run more than 2-3 minutes, but it fires right up 100% better than before just slightly missing, 250k on truck was runnning great before except for start up for a few seconds
remans from pensacola
old
no idea
no
no
but i wasnt complaining of blue smoke and roughness before i changed them. i replaced them because one or more was leaking and evertime i started it after it sit for more than an hour or two and it would miss and blow white puffs then clear up, and they had never ever been changed, the dates were 7/93 on em! what exactly are you looking for on the ' how did they look ' part? now it is constant blue and runs rough at 2k, but it could possibly still have some air bubbles it hasn't run more than 2-3 minutes, but it fires right up 100% better than before just slightly missing, 250k on truck was runnning great before except for start up for a few seconds
The guy that just "rebuilt" my injectors told me the following for timing by ear.
Install the "new" injectors, take the pickup out run till normal temps, shut it off and restart, dont wait for the glow plugs to cycle.
If it starts without much "turning over" it's close, then wait exactly 15 min.(actually wait that long, time it) Then after 15 min restart without waiting for the glow plugs to cycle. Engine should start with few revs. If the engine needs to whirl over then timing should be advanced. (advancing meaning the width of the mark movement).
Granted this is kinda vague, but its by ear. The guy has 20+ years rebuilding pumps of all kinds, pickups, tractors, etc.
Just my .02's
Install the "new" injectors, take the pickup out run till normal temps, shut it off and restart, dont wait for the glow plugs to cycle.
If it starts without much "turning over" it's close, then wait exactly 15 min.(actually wait that long, time it) Then after 15 min restart without waiting for the glow plugs to cycle. Engine should start with few revs. If the engine needs to whirl over then timing should be advanced. (advancing meaning the width of the mark movement).
Granted this is kinda vague, but its by ear. The guy has 20+ years rebuilding pumps of all kinds, pickups, tractors, etc.
Just my .02's
Pensecola does not have the best reputation around here. I would remove those injectors and have them pop tested before you even consider touching the timing. I guarantee you they are not right based on what you say!
