injector install questions

[01 lb7]

well would the timing even need changing for bb codes?

 

[vegas39]

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!

I'd be willing to bet hes got some leakers.

 

[TWeatherford]

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

Mine was approx 3 degrees BTDC for several years. I run a push button glow plug system so I only glow for the first start of the day. Even with only 3 degrees of advance, it would fire right up on the first or second compression stroke anytime within 8 hours of being at operating temp. Now, with 9.5 degrees of advance, it starts just the same as far as I can tell.

 

[redneckaggie]

the difference from one letter code injector to the next is minimal. The point here is that you are not testing anything scientiffically you are throwing parts and ideas at the engine. If you did not test the new injectors before installation then it is exactly as mel said. you have exchanged something of unknown condition for something else of unknown condition. I have heard multiple people that sell NEW injectors say to test them before installation because it is not extremely uncommon to find a bad injector brand new.

You are concerned about changing the timing and earlier stated that you needed to retard the timing because of the pressure differences in a new(not wornout) g code and a unknown set of reman injectors. how do you know there are pressure differences because you do not know what the old ones popped at when you took them out and you do not know what the new ones pop at so????????????

The other thing that you are forgetting is that the ip is part of this equation also and it also wears as does every part on the engine. what you have basically told us in this thread is that you have a unknown ip, unknown injectors, and unknown timing. see the lack of scientific logic here?

all that being said I would pull the injectors and test them

 

[redneckaggie]

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

The how did they look insinuated exactly that, were they extremely black on the tips, were they wet on the tips, was the hole carboned up like they had been leaking compression by. injectors are like a spark plug in that you can tell a lot about the condition of them by looking at the tips(nozzles)

also were you positive to keep everything clean to be sure that no grit, dirt, or grease or ANYTHING got into the lines or the injectors

 

[01 lb7]

Ok so I just ran it for a half hour or so to make sure no air was in the system, and at idle, it is very shakey, raise it above 1k is normal and 2k it has a very slight miss, like one every5-10 seconds. Would you still say injectors or could it be that the pump isn't opening the injectors correctly. I know you say the injectors are an " unknown " variable but I just don't buy the injectors making it do this yet. And I understand everything that has been said thus far, I just don't want to miss something that could save a lot of time

 

[01 lb7]

No dirt was in the holes I kept them clean and clear. A couple of them had darker tips than the rest, but they all looked similar

 

[Wyreth]

I know you say the injectors are an " unknown " variable but I just don't buy the injectors making it do this yet.

The blue smoke at idle means there is a good chance one or more of these injectors is in fact leaking.

The rough at 2k could be a sign that your IP was bad too. The "new" injectors likely pop higher than your warn out G codes, and are putting more stress on a weak pump. Has it gone more than 125k-150k miles? Thats how long they last, and you gotta be kinda lucky to get farther than 125.

At this point, forget the timing. There are other things you need to check FIRST. Otherwise timing it will not mean squat.

Mel it it perfect. Check your injectors FIRST, if they're good, then move on to what else could be the problem. Doing anything before that, isn't going to tell you anything at all.

 

[icanfixall]

My guess is the rebuilt injectors from pensacola. They have a mixed track record for poorly rebuilt injectors. They do have a great claim to fame ebay statement but what has happened to a few members here speaks plenty... Its really difficult to actually find a set of rebuilt injectors that pop at the correct pressures and.. Don't leak thru or hang open.

 

[SHARPIE]

Alot of good info in this post..

 

[snicklas]

Ok so I just ran it for a half hour or so to make sure no air was in the system, and at idle, it is very shakey, raise it above 1k is normal and 2k it has a very slight miss, like one every5-10 seconds. Would you still say injectors or could it be that the pump isn't opening the injectors correctly. I know you say the injectors are an " unknown " variable but I just don't buy the injectors making it do this yet. And I understand everything that has been said thus far, I just don't want to miss something that could save a lot of time

My take on this statement, and this is troubleshooting 101..... no matter what you are working on. Machinery, vehicle, computer, plumbing, toilet..... light socket.

If you have a problem after you change something, look at what you changed.......

I have been working on thinks my entire life.... and have fallen into "It can't be the new part" spiral..... but think about it.... if you have a light fixture, and everything is working, and you change the light bulb, and now that bulb does not work, where is the problem? The switch, circuit breaker...... probably not, I would put the bulb back in that was working. I am not trying to talk down to you..... I am just trying to show you what may be happening..... trust me, BTDT!!!!!! I am a computer administrator for a living.... and at the time I had a partner that I worked with, if they had a problem with whatever they were working on, and asked for help, or if I were asking the help.... we would always start out with the "stupid" questions...... is it plugged in, is the power strip on, are you using the right keyboard/monitor/mouse (multiple computers in the area)...... and most of the time we breezed past the "stupid questions with a yes/no as appropriate, and then moved to the more advanced troubleshooting....... but you know... there was a time or two when there were multiple power cords on the desk..... and I was POSITIVE the cord was hot that I was using..... only to find out I grabbed the wrong one that was not plugged in...... but I was ready to tear the machine apart and rebuild it because something else had to be wrong.........

Please, take the guidance of the members here..... they are pointing at what they believe is wrong, because they have been standing in front of their trucks, with the exact same situation you are having....... (BTW - The picture of Mel's blue Slantnose (The Moose Truck) in the picture in his avatar...... it is smoking like that, because it had 3 leaking injectors)........

 

[RLDSL]

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.

the input pressure didn't make any difference at the same volume, as any excess would have just flowed out the bypass via the return line back to the tank, but a difference in pop pressure from a new injector, or even a different old injector will change the injection timing.
The pump is set to release it's fuel at a given point on the plate on the pump and it's internal resistance has something to say about that. WHen it sends a shot to an injector if it now has a higher pop pressure, it is now going to fire later than what it was initially set for as the pump is going to have to build up a tad more pressure to get the thing to open up and spray which will take a fraction of a second longer ( inversely if the pop pressure is lower the the timing will be sooner)

 

[RLDSL]

After having spent half a day trying to time a pensacola pump and not being able to get a decent signal off the thing, off either #1 or 4 I would venture to guess this engine is having problems with it's injectors. Pensacola is basically a dirty word in my book. THey rank right up there with diesel careless