Is it the pump or injectors?

[Kernel]

Recently my 1st Gen started to get a fluttering sound when at low idle or about 1/4 pedal while in gear going down the road. It almost sounds like you are feathering the pedal. If you have the radio on you can't hear it nor can you feel it. In "park" it sometimes sounds like a mild miss but the engine doesn't idle rough. While in gear with your foot on the brake there is sometimes white smoke from the exhaust. It still runs strong and starts up on the first crank. The white smoke leads me to believe it's an injector. It has 202,xxx miles. From service records the pump timing has been increased to what I don't know, and the idle was adjusted up. The only thing I have done to it is a smoke screw adjustment and I turned the star wheel. Any thoughts?



Scott

 

[cerberusiam]

The white smoke under load sounds like injection timing being way late. A miss at an idle could be an injector hanging but also an injection timing problem. From the sysmptoms you describe and the miles it sounds like the VE is getting ready to go tango uniform. You could also have injector problems developing that are confusing the issues. RPM's fluttering when the throttle is at a constant position would indicate the pump is having some issues.



That is about the mileage mine started acting strange. I drove it like I stole for another 30k miles before it gave up completely but you never know. Good luck.

 

[Kernel]

My next question was getting at how long do I have? Can I keep driving her around until I'm stuck? How much do injectors run (recon's) and what about the pump? I am guessing a few hundred for the injectors with a core exchange and probably less than a grand for a recon pump. Is it worth going ahead and doing or just starting out with the cheapest and hoping for the best? Thanks for any help guys.



Scott

 

[Kernel]

Oh yea, forgot to mention the MPG are not as good as I thought they would be (around 15 for highway and backroad cruising).



Scott

 

[BushWakr - RIP]

First thing to do is run a good healthy double or triple dose of fuel additive thru it... try some stanadyne performance formula (SPF)

See if that helps at all. It may take a good half tank to full tank to see any difference but it will tell you if you have a bit of fuel issues.

Next it may well be your injectors. Over time they begin to loose their pop off value due to wear.

It may be that you have one or two injectors that are releasing a bit too soon or too late because they are sticky.

That can create some of the symptoms you describe.

(Normally if the injector(s) are sticking then the injection cycle will be delayed, which in turn results in the "effective" timing being retarded and with that comes smoke and poor idle quality.

This is assuming your fuel filter is new of near new and also that you have not gotten some bad fuel.

If the filter is old or if you suspect bad fuel then dose the snot out of it, change the filter and burn it off.

Get a full charge of new fuel, put in some more additive and install a new fuel filter.

After that, make sure that the turbo hose clamps are snug, and that the rubber boots do not have any cracks. You'll need to pull them to do a good inspection. When you get them off, roll them between your fingers... look for cracks or signs of brittleness.



Give some of that a try and get back to us here with your results and any other symptoms you can detect...



pastor bob..... hey, lets here from the choir here guys.....

 

[JLEONARD]

How much do injectors run (recon's)

My thoughts... . shop around and you'll probably find a set of new performance injectors for similar $$ rather than having the stock ones rebuilt... . you won't regret it.

Jay

 

[Kernel]

Forgot to mention I did change the fuel filter after I ran the fuel low and went to a place that I feel has good fuel. It seemed to do better for a little while then she went back to the way she was. I could tell a difference with the filter change though... Where can I get the fuel additive at?



Scott

 

[ARedetzke]

quote "Where can I get the fuel additive at?"



You can most likely get diesel fuel additive wherever you fill up. If not, try the CO-OP, or a truck stop.

AJ

 

[dpuckett]

If it were me, and I have been in your position more than I care to admit, I would run the additive throught the tank like the good pastor said, except I'd run double what the label recommended for the first tank, it wont hurt anything. If that dont help, pull your injectors and have them pop tested. They could be worn, or carboned up, either of which can be remedied by cleaning and resetting the pop pressures. Most Bosch certified shops can do this for what I consider reasonable. One thing I will add is, if you need one new tip, you need six. If you have one new tip, and 5 old ones, that throws the set out of balance, as the old ones have an effective 200K of honing, so to speak, and will flow more fuel per stroke. Or is there a way to offset this, too, Pastor? This is by my experience with one shop here in the swamp. If you need new tips, at $35-45 a piece, you may as well get new performance injectors.



If the injectors check out ok, and are somewhat even, then it could well be the pump wearing down. Next step would be a timing check, and make sure you find TRUE tdc by one of a few methods out there. The timing pin is to be used for a guide to get close, until proven accurate. It is good enough for valve adjustments, but for timing, you need to be dead on. Or it could be the weight of your foot. Some of us here have a tendency to use the torque all the time. takes fuel to make power and use it... .



Check your lift pump pressure for kicks and giggles while you're under the hood. If the LP aint doing its job, it creates lower pressure one down the line, and fuel wont atomize properly.



I agree, with your 3. 07s, and I assume no OD, you are turning close to the same RPM as I am with my 4. 10s and OD. I get 19 locally, 60% city/40% hwy. I got 21-22 in Colo; 23 hwy @65-58. been a few miles since then, though. 15 is what I get pulling 12K of hay, livestock, etc.



Daniel

 

[cerberusiam]

Most Bosch shops will rebuild your injectors and pump for a reasonable price but that varies by locale. A good shop that does performance work can swap in a bigger set of tips and rebuild the OEM barrels for around $65. A pump rebuild should run $500 to $700 depending on how many parts need to be replaced. A new pump was $1200 to $1500 but considering Bosch's antics lately that may not be true anymore.



As far as how long it will run, flip a coin and randomly assign time frames to each side. That will be as close as guessing when it will die. The VE pump seems to have a mind of its own when it comes to living and dying.

 

[Kernel]

Thanks for all the help guys. I want to keep the truck pretty much stock, but if performance injectors are just as expensive as the recons, would 180's or 190 performance injectors too much for the 727? I would hate to be looking for smoke and see my trany pan sliding across the road



Scott

 

[GGott]

Hi Scott... Had my stock injectors R/R'd for $34 apiece. Of the six, five were popping early. Previous to the injector overhaul, my problems were much like yours-- pump? or injectors? Made a good fast 750km road trip with probably triple strength Stanadyne fuel additive. Truck kept running better and better with the injector problem becoming isolated. Good Luck... .

 

[dpuckett]

Scott, the 185/190 injectors will flow REAL close to what stock injectors for our older nonIC pickups flow, so no, they shouldnt trash the transmission just yet. Plus, the 185s (not sure of the 190s) have 5 holes- better atomization and spray patterning.



-DP

 

[Kernel]

okay, went to the flying J, got some injector cleaner/fuel treatment and triple dosed her. I have put about 200 miles on her this weekend and haven't had a problem with the fluttering yet. It actually seems to run smoother and idle a bit better, but I still have some white smoke while in drive and the brakes on, not as much but still there. Could it be the timing has slipped?





Scott

 

[BushWakr - RIP]

No the timing can't slip in our trucks... the pump shaft is keyed to the cam gear.

The pump and injectors can wear over time and that can result in a bit of timing change.

Normally an injector will slowly deteriorate over time... the fuel running thru it actually wears it out which is almost like having the injector extrude honed.

Basically this causes your injection cycle to begin a bit early, or, late if the injector is sticking, or , dribbling fuel and other symptoms.

What you want is to have your injectors all within about 2 bar opening pressure... . the pump/delivery valves running clean and a proper timing reset.

Since you are seeing some improvement after adding the fuel conditioner I'd suggest you're on the right track.

Finish that tank and do it again.

Remember that our pumps are lubricated and cooled entirely by the fuel passing thru it so the additive is doing more than just cleaning things out.



Stick with it for another tank full and lets see how you're doing at that point before you go spending some $$$$... .



pb...

 

[Kernel]

I bringing this thread up to the top for follow-up. I have ran a couple of tanks of fuel that were treated as suggested and have started on a fresh untreated tank and my "fluttering" is back. White smoke under load (in gear with foot on the brake) has gone back to the way it was. It never left completely but was cut in half with the fuel treatment. I figure this will be cut out once I get the timing checked, but am I looking at injector problems? I did find the KSB valve had lost it's wire, fished it out and put a new connector on it, and is now hooked up. Don't know if this had anything to do with the timing, which is what I understand it does when cold started until the engine warms up (am I understanding this correctly?). Guess I'm about ready to put some gauges in and buy 190's.



Scott

 

[cerberusiam]

The KSB advances timming until the engine comes up to operating temps then returns the timing to preset. The same system is used to advance timing as rpm advances and fuel pressures come up.



With the engine warm putting it in drive and standing on the brake and go pedal you should see gray to black smoke. White smoke is an indication the injection event is behind the curve. Injectors sticking could cause that but I would think you would feel a pretty good miss as the odds all of the injectors sticking the same would be quite high. The injector cleaner will mask small and developng problems by increasing the fuek burn rate so things look and run better. On straight #2 you should not have the white smoke or flutter. If it changes between tanks I would suspect a mechanical problem.



The flutter you mentioned, do you feel it or just hear it? Is it something that only happens when you are cruising at a steady speed? Does it disappear under acceleration?

 

[Kernel]

You only hear the flutter, with the windows up or the radio on you don't notice it. It only happens under light pedal (about 30mph) at a steady RPM (I don't have a tach) and goes away with acceleration.