Is this injectors?

Need some diagnosis help. Think I have some dirty and/or failing injectors but want to make sure before I drop the $.

I had a fuel contamination issue I discussed previously with the "coating" inside my tank breaking down. Here's what I did. Replaced tank with good clean used tank - new sending unit with new strainer, flushed and blew out the lines from front to back - pickup and return lines, replaced complete filter housing assembly, and replaced the lift pump since it was weak under load according to the fuel pressure gauge.

Here are my symptoms:

Hard start when cold - this has been going on for a month or so. Turns over strong and it is trying to start but takes a while. Seems to be dumping fuel in because it really belches gray/black smoke when it finally starts. When it's warm - starting is better but not like it has been. Also have to "clear it out" by hitting the throttle as it wants to spit and sputter some after start up.

Has been driving ok around town - throttle response has not been the crispest, but ok.

Took a 4 hr one-way trip to NC this weekend. On Friday - noticed some slight surging and bucking trying to hold steady throttle going down the interstate. Coming home last night - the surging and bucking was much worse. Also noticed the boost gauge going up and down as the engine surged. Does ok under load, but it does not like light steady throttle.

My thought is that I have an injector or mutliple injectors that got trash from the contamination in the tank. I'm thinking they are squirting rather than spraying causing the hard start and the surging. The injectors are 2-3 years old and probably have 30-40K miles on them so they "shouldn't" be worn out. They were new Bosch units from Heath.

2 questions:

Does this sound like an injector issue?

Can they be taken apart and cleaned?

Thanks as always for your input!

Sounds a lot like you could have air in the system.

Connect a small clear plastic tube to the fuel return line on the injector pump.

Run the rig and see if you are getting bubbles traveling through.

If need be, loop the clear tube up past a wiper and then back under the hood.

Air bubbles will really mess things up.

Can cause hard starting, stumbling, soft throttle and all that you have described.

How many miles on the rig.

Yesss the injectors can be repaired, but this is a task best left to the specialty shops that do injectors and pumps

Hard starting can be due to bad glow plugs too

when was the fuel filter last changed ???

You have symptoms that can be related to several items.

Any codes popping up ???


When was the PMD last changed out ???


Keep us in the loop


Missy

Robyn - Whole fuel filter housing and filter just changed last week when I did the whole system clean out thing.

Glow plugs are less than a year old - quick heats from Kennedy. Put 4 AC Delcos in on the driver side last week just to see if they changed anything. It didn't. Checked the glows using the old batter cables and they glowed pretty quick.

Miles just hit 300K

Check engine light has never come on but have not pulled codes yet.

PMD change out has been a while - have a Heath remote mounted unit. I do have another one I can swap out that came on my last IP. Should I swap that out to eliminate it as a possibility?

Thanks

Pulled codes - have a misc unrelated trans code but also have a new one:

P0004 Fuel Volume Regulator Control Circuit High

Anybody help with this one?

Also - I did connect some clear tubing on the return line. I've got bubbles. Are there supposed to be no bubbles at all? Didn't show many going steady down the interstate but there were a few. Shows more with start and stop driving.

It is running like total crap now.

Help. Have a trip coming up soon and really need the big rig running.

Any air in the system is a bad thing.

Air is getting in somewhere prior to the lift pump on the frame.

Sort that out and repair as needed.

There should be ZERO Bubbles streaming through.

Likely a tank pickup tube connection or a hose between the tank and the lift pump.

Keep us posted

Missy

OK - thanks. I'll check that out. I did just replace the sending unit so maybe it's something with those connections. Weird part is that it was doing this before I changed the sending unit. Do you typlically use teflon tape on those connections and the lift pump connections?

Thanks

I just chased down some odd behaviuor to my Heath pmd relocater.

I had a tcc code, fuel trim too short and cruise control wasn't working.

Turned out to be a big blob of green corrosion hiding under the resistor in the pmd.

Cleaned it up and everything was good again.

Probably not your problem, but it's "no cost" to check.....

OK - I had the clear tubing plumbed in the wrong spot. Put it on the return out of the pump and looped it - NO bubbles at all.

Also swapped out my PMD with an extra I had - no change.

The IP was replaced approx 2 years ago and I've had a couple of them fail and this does not seem to be exhibiting the same characteristics.

Has this pretty much narrowed it down to injectors?

Hard start, kicking and surging going down the road, terrible throttle response at this point.

Thanks!

It could also be a fuel quality issue. If you haven't done something to be SURE you are supplying fresh, clean #2 Diesel, do so. A bunch of gas or some other non-Diesel contaminant can also cause your issues.

DMAX - after dealing with the fuel contamination issue already and replacing the tank, filter, blowing out lines, etc. I'm getting fuel from hi-volume truck stop type gas stations. Staying away from the mom and pop. Short of sampling the fuel - not sure what else to do on a regular basis.

I have new injectors arriving tomorrow so we'll see. Just hope I haven't wasted the $.

UPDATE - new injectors installed tonight. Truck is running much better but still not 100%. If I start from a dead stop it seems to "bog" some until about 2500 rpm and then it really hauls. It's pulling ok up until 2500 but then it really takes off until it shifts. It does the same thing after each shift.

Runs pretty good down the highway - still seems to be surging very slightly.

Not sure on the starting yet. The new injectors took a while to bleed of course and a couple of starts after that took longer than normal and still had to hit the throttle to clear it out.

Any thoughts?

Thanks

Air filter? Collapsed intake plumbing?

Dmax - just put AFE air intake on so that's not it. Could a worn timing chain cause the hard start and/or delayed response under load? Truck just hit 300K and orginal chain as far as I know.

Was thinking of going with gears to replace - thoughts?

Thanks

Timing chain could, but not overnight. It would be a degradation over time, and goes mostly unnoticed. At the same time, it's way overdue at 300K. You may have a culmination of issues that came to a head all at once. If injectors helped, a timing set will probably help more. Tackle them one at a time. It runs, albeit less than ideal, but it runs. Without getting hands on, it's difficult to say.

Quote:

---

Originally Posted by 65-f100

Replaced tank with good clean used tank - new sending unit with new strainer, flushed and blew out the lines from front to back - pickup and return lines

replaced complete filter housing assembly

replaced the lift pump since it was weak under load according to the fuel pressure gauge

The injectors are 2-3 years old and probably have 30-40K miles on them so they "shouldn't" be worn out. They were new Bosch units from Heath.

---

Quote:

---

Originally Posted by 65-f100

Whole fuel filter housing and filter just changed last week when I did the whole system clean out thing.

Glow plugs are less than a year old - quick heats from Kennedy. Put 4 AC Delcos in on the driver side last week just to see if they changed anything. It didn't. Checked the glows using the old batter cables and they glowed pretty quick.

PMD change out has been a while - have a Heath remote mounted unit. I do have another one I can swap out that came on my last IP. Should I swap that out to eliminate it as a possibility?

---

Quote:

---

Originally Posted by 65-f100

I did just replace the sending unit so maybe it's something with those connections.

---

Quote:

---

Originally Posted by 65-f100

just put AFE air intake on so that's not it

---

I've tried to break out all the replacements you've already made from your posts. Seems like you recently did an awful lot of work - new fuel tank, sending unit, and lines; new filter housing; new lift pump; new air intake. Fairly recent glow plugs, PMD, and injectors (even before the latest new injectors).

Were these issues prior to all of this replacement? Or after? What was the reason for all the replacement? You discussed the fuel tank coating "contamination" but did you have all these symptoms before or after you discovered that?

It just seems like people are shooting in the dark with suggestions without seeing the whole picture and timeline. Also that since so many changes were made in a short period of time that opens up the possibility of something being connected wrong or something being disturbed while doing all the other work. Sort of like a recent electrical problem a friend had where a light wouldn't work so he replaced first one switch, then the other (3-way switch circuit), then the breaker - only to find that the recently replaced lightbulb had already burned out... Then had problems because he had connected up the switches wrong while he was replacing them...

Have you seen this:
http://www.thedieselpageforums.com/t...=39850&page=12

Sounds like the same sort of problems I was having, as was this guy. You replaced your sending unit and sock too... just sayin.

OK to recap.

I've noticed slight "bumping" going down the road for a while - very slight. (Thinking back - this is why I suspect the timing chain may be part of the equation)

Approx. 3 months ago I started having the hard start issues but was still running "normal" at that point . Just took a long time to start and belched when it did. Also had to start "clearing" it with the throttle right after start up to get it to idle normally.

The fuel contamination issued occurred after this - Memorial Day weekend - and that is when the real bucking and missing started. That is what led to replacing the tank, sending unit and filter housing as well as flushing all the lines. While diagnosing all of that - I tested the lift pump pressure and found it dropping to 0 under load - that is why I replaced it. Just FYI - the sending unit and fuel filter housing were both new Delco units. I had read the same post about the sock/strainer issue and that convinced me to go the Delco route.

After checking for air in the return line and finding 0 bubbles - my next logical step was the injectors. These are new Delphi units by the way - not low-buck remans.

I can hold the throttle steady at 2000 rpm so I "think" the IP is ok.

Are there other tests I can do to check it? What about the fuel solenoid? I read some other posts about it

Would the optic sensor play any role hear? Can it get dirty? Wondering if some of the trash from the fuel contamination may have gotten past the filter.

Would the timing chain or optic sensor attribute to a hard start?

Just scratching my head a little. Appreciate the input as always. It's at least driveable now but would really like to get it right.

Latest update - wife driving it on a 4 hour trip. Called about 2.5 hrs into the trip and said it's bucking again. My thought is that the timing chain is very sloppy causing it to jump and buck under steady throttle. It does ok under load because of the additional load and tension on it.

Does this make sense?

I'm just at a loss over what else it might be.

Does the PCM have any active or stored trouble codes?

There can be codes present that do not illuminate the cel.

The p0004 is a red herring I'm thinking. Here's some support for that hypothesis : http://engine-codes.com/p0004.html

If there are codes, clear them (after recording them) and then see what codes return after running it again.

Timing chain seems unlikely to me. Improbable, but not impossible...

I am in Pauline,SC, about 80-90 miles up I-26 west from you, I have a new Clones timing set you can have really cheap if you want to try it. I think you are bypassing the one place I would look, the IP, if you had bad stuff that made it into the pump it would cause bad things inside it.

I also agree that you need to try and narrow things down and not just throw parts at it hopping for the fix.. Pull the codes, if you aren't sure how, say so and we will tell you how to do it.

A surging can mean several different things, you need to first see if there are any codes, if not, might try a new good PMD, not the cheap ones.

If you get stranded up this way, I might can help ya.

The p0004 code is the only code it had other than a transmission circuit code that it has had for years. I do have a scanner and will check codes again when we get home.

Based on the fuel contamination I've worked my way from the back forward trying to think logically. I'm really trying not just to throw parts at it. The tank was full of material hence I replaced it and the fuel sending unit (Gauge had been bouncing for a while anyway). The next step was blowing out the lines and replacing the fuel filter unit. The filter unit has been seeping a little fuel anyway and also had trash in it, so I just replaced the whole thing. Both sending unit and filter housing are new Delco units. After testing the lift pump and seeing the pressure drop to 0 under load - it was replaced. Thiinking this was still fuel related based on the symptoms - the next step in my mind was injectors.

The PMD was replaced with a known good unit that was pulled off my last new IP (I have the heath remote mounted PMD currently).

I asked about the IP on my fuel contamination post, but the consensus was that it should not have been affected. I did take the injectors I pulled out apart and there was no noticaeble trash in any of them. Now I know that if could still be in the pump and never made it to the injectors, but how do I verify that?

Are there other ways for me to test the IP other than the hold it steady at 2000 rpm test?

The symptom really occurs under steady throttle (Highway driving). It really does not kick and buck too much in around town driving when you're on and off the throttle. I was thinking that slack in the timing chain would cause the timing to jump around under steay throttle and may not be as noticeable in on and off throttle since the slack probably tightens under load. Is this reasonable?

Did add an extra dose of stanadyne grey additive to my last tank of fuel just for good measure.

Trailrider - thanks for the offer on the chain set - may take you up on that. I'll let you know.

Next step?

I can't remember if this was suggested already and its going to sound cliche, but have you checked and cleaned the ground points yet?

Try removing (bypassing) the optical sensor filter. It has been suspected in this sort of behavior. Also, when was the last time the fuel filter was changed? Where are you measuring pressure, before or after the filter?

If you had fuel/tank contamination then the fuel injection system is the place to start. If changing relatively low miles injectors helped that leaves one key component. Just be good and darn sure that your fuel supply is good and clean before you replace the pump.

Just a very blind shot in the dark, did you check the fuel strainer under the fuel inlet on the IP? With known fuel contamination you have mentioned replacing filters ect, what is the condition of the inlet screen?

Like I said, shot in the dark. Good Luck!

Brian

OK - latest update.

I drove the truck home approx 4 hours. Still driving much better than it was prior to the injector replacement, but still surging pretty consistently. Not bucking like it was before.

It really does feel fuel or timing related. I have to give it a lot more throttle than I normally do to get it up to speed.

Kennedy - what is the best way to test the fuel? I've burned through almost a full tank with extra stanadyne grey added. Just refueled on the way home at a Pilot truck stop so I'll keep driving it to see if it changes behavior.

bshull - I was not aware of an inlet filter on the IP. Is it a screen type filter? Is it where the rubber line attaches from the filter housing? Certainly worth a try.

I still plan on replacing the timing chain based on the miles - opinions on chain vs. gears?

Thanks!

The ip inlet filter is below where the rubber fuel line enters the IP, unscrew the compression nipple and remove the fitting that the nipple screwed into. You might be chasing a ghost but to check it cost nothing but a little air in the system.

I have timing gears, some swear by them, some swear at them. The question is how much longer do you plan on running that engine? A good timing chain is cheaper and will probably outlast the engine.

Good luck

Brian

bshuill - I will check that tomorrow - it very well could be that if some trash got through. Certainly worth the time to check it. How nice it would be if you are correct!

We're planning on keeping it for several more years. On the gears - not as much worried about the longevity as the chain on there now is a little over 300K. I've ready many posts from other using them that they have experienced better drivability (crisper throttle) a little more pwer and maybe a slight bump in mpg. What has your experience been?

Thanks

It is hard for me to tell, I put in the P-400 engine, att turbo, and heath tune at the same time as the gears so I do not have a direct reference.

I pull 18 mpg pushing 75 mph on the highway and for a burb that has 3.42 gears it performs very well.


Brian

I think you might find the strainer plugged up, it is the only thing you haven't checked yet.

As for the gear or chain ---- with 300k on the motor, I would go with a new chain set if it were me, I am going to a gear drive in my build just because it will be a new motor, it mine had that many miles and I wanted to freshen things up, the money for the gears would be better spent on a better turbo than the GM junk.... just my thoughts...and you should consider a new balancer if you haven't replaced it yet...

Latest update:

Inlet filter certainly had trash in it. Bshull I thought you had nailed. It had enough in it that I thought it was going to solve my problem. If only I were so lucky. I cleaned it out good. Took both little screens off and blasted them with brake cleaner and air. Opened the little spring loader valve on the end as well. It was very clean when I reinstalled it.

Truck has noticeable more power on the top end once it hits about 2500 but its still struggling somewhat to get there. I'm narrowing down to the IP which I've been trying to avoid. Thinking some trash still got through and may have damaged it? It's still starting hard and stilll surges going down the road. If I rev it in neutral and hold it around 1800-2000 - you can actually hear and feel it missing. It will hold the rpm steady but it has the occasional little surge by itself. Not running away like one of failing ones in the past. Not exactly sure on the internals of the pump, but it really feels like I have 1 or 2 cylinders missing. Does the IP have separate internal valves for each cylinder?

Would a cylinder balance test help me determine if it's the IP?

Thanks for the continued help. Every little thing I've done is making it better. I'll still probably go ahead and put a timing chain set on since it's overdue and would give me some peace of mind. It would also eliminate that as a factor too.

Your 1800-2000 rpm "surge" is not a positive sign of ip health. As in; not good.

I would be interested in some real time data from a proper scanner to see what it's doing....

GreatWhite is right, things are pointing at the IP. It would be nice to see some data from a good scanner.

To recap your problems, you have a surging bucking problem at steady throttle. Bottom end power feels weak.

Things done, new injectors, different PMD, fuel supply system fully cleaned, fuel system air tight.

If it were me, I would replace the IP. Still not 100% sure but with everything done it really sounds like IP. I would want scanner data to back it up before spending a grand tho.

Let us know where you are going to proceed,

Good luck

Brian