Is this injectors?

[65-f100]

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!

[Robyn]

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

[65-f100]

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

[65-f100]

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.

[trbankii]

Any air in the system is a bad thing.

[Robyn]

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