Eight bad injectors?

[DOE-SST]

I'm really losing my interest in these IDIs.

I did spend 3 hrs reading old posts without any new leads to pursue.

1994 E350 7.3L IDI

Just installed a Pensacola rebuilt IP that squirts fuel to all injectors reliably. I cracked open all injector line nuts at the injectors to verify.

Checked all glow plugs, all at .5 - .6 Ohms using a quality Fluke meter. Pulled two just to verify good physical condition. They were Berus, no erosion.

Tested a glow plug by removing it, attaching it to wire harness, grounding it to the block, and turned key on. It went to 400+ degrees in 2 seconds. Used a $350 Raytek Infrared meter to measure.

Pulled one injector and disassembled it. Found very small amount of fine crud.

This vehicle sat for a year, and had sludge in the fuel system. I cleaned out the fuel tank, replaced the filter, cleaned out the steel injector lines with MEK, and replaced the IP. I'll be putting an in-line filter just before the IP today. I put a sludge dissolver and clean diesel in the tank.

It ran fine yesterday, lots of power, no smoke, started on first try.

Today, not even a hint of starting. I have two good batts and a quality batt charger on them. I swapped out the glow plug controller with a known good one, but no improvement.

Am I missing something, or are the injectors a prime suspect. I find it hard to believe they would all go bad at once.

Thoughts?
Opinions?
nasty comments?

 

[TWeatherford]

Injectors aren't your problem. I've never heard of injectors causing a no-start, though I'm sure its happened. Generally they deteriorate until the engine runs rough and low on power, and they'll stick open and leak fuel and you'll have a nice grey haze coming out of the tailpipe.

Sounds to me like you have leaky fuel return lines, which you would have disturbed when doing the ip and looking at the injectors. If they leak air (which often happens even when they don't leak fuel), they allow the fuel to leak back toward the tank on the inlet side of the injection pump, so the engine can't fire until it re-primes itself. If you need to drive, you can prime it like you did after the you replaced the ip, but replacing them soon will save your starter. A kit can be bought on ebay for $30.

 

[Diesel JD]

Somehow you're air locked unless that Pensacola Pump somehow snapped the shaft in this short time. Getting it all hooked up right on an F-series is a pain I don't know that I can even imagine what it would be like on an E-series. It's worth it once they are right, I'll tell you that much.

 

[icanfixall]

Wel my guess is the black crud you got out of the fuel system. Sounds to me like its some kind of alge groth in the fuel system. You posted that the truck sat for a long time before you got it. Usually crud like alge starts growing and causes all kinds of fuel system issues. Very hard to get past that too. Cleaning out the fuel tank was a good idea. Now replacing the fuel filter and purging out the injection pump is next on the list. If the truck has a mechanical driven fuel lift pump then you would be better off by filling the new fuel filter with something. That way you wont have to purge all the air out of it. An agle killer with some fuel cleaner or just diesel will help things. Just fill it as full as you can. Then crank for about 10 seconds and purge the trapped air with the shrader valve on top of the filter housing. Post back how its working...

 

[gandalf]

Go back and read my posting, and all the replies, from a couple months ago, toward the end of May. Think about that and how it relates to your current problems.

Running problems

Hope this helps a bit. I'm still working on mine.

 

[DOE-SST]

last night's efforts...

I have replaced all the fuel return lines with new hose and clamps and connectors. The current ones were all painted gray, probably factory originals.

I removed and disassembled all the injectors. A little bit of fine crud, some dark brown goop, and all of them had the needles frozen in place. I didn't realize they slid out until a bit more research. But none of mine would slide out, not even after 30 minutes in an ultrasonic bath of new carb cleaner, on high heat.

After 1-2 hrs of ultrasonic, using MEK, and some forceful pulling with soft-jaw pliers, I managed to get the needles out. The needles were in the closed position. I don't understand how this van even ran previously. But, it did run, so the injectors are probably not the cause of the no-start problem.

Regarding fuel contamination. Most of my previous testing was done using a pressure pot of new, treated diesel. It has a NIST calibrated gage and new filter. It is a tool I use on jet engines.
The new fuel filter has less than two gallons through it, so I doubt it is clogged. The tank was cleaned out with MEK until the paper towels were spotless. Fresh fuel and biobor was added. I've added a see-thru filter just before the IP to see if I still have any contamination when I try my next restart. The Rebuilt IP pumps fine, and all the steel injector lines were thoroughly cleaned out.


I'll give all the injector metal parts a long bath in MEK, then reassemble with new o-rings and gaskets, and try starting it.

I'm wondering if there might be an electrical issue. The owner installed a kill switch (made in china) between the power wire and the glow plug controller. This changed to sound of the controller from a clicking to a humming noise. I suspect he fried the relay, so I pitched his switch in the dumpster, removed the entire GP controller assembly and installed a serviceable one. The fuel shutoff solenoid seems to be working fine, it makes the appropriate clicking noise and I get fuel squirting out the ends of the injector lines. Is it possible a fusible link, wire or fuse might have been damaged that is contributing to the problem?


Another question. The injectors had small washers (shims?) between the shell body and the spring. I'm guessing these determine the pressure the injector opens at. During the ultrasonic baths, some of these fell out. Is there a measurement for spring extension I can use to reassemble them? Or should I just make sure all have the same extension, as close as possible? Or do I need to rig a nozzle tester to insure these open at 1800psi +/- 100.


Thanks for the help guys.


BTW, an E-series van ain't that hard, if you've worked on general aviation aircraft before. Step one is always removing the front passenger seat, even for small jobs.

 

[Dsl_Dog_Treat]

FWIW its time for a new set of injectors.
The shims are relative to the pop off pressure for each injector and if they end up in another injector, you now have 2 injectors that will pop off at different pressures unless you have a pop tester to reset them and match all 8. Plus if they were seized in there closed its best to just replace them since they are not that expensive and will complete the refresh of the fuel system.

 

[Diesel JD]

It's a shame you don't have a pop tester cause obviously you are mechanically inclined enough to not screw the injectors up, but Dog Cather is right, you mess with the injector internally you have no idea what you have until you either replace them or reset them with a pop tester. Spec is around 2000+-a couple hundred and they should all be within 200 psi but 50 would be better.

 

[DOE-SST]

I've got a spare small O2 tank, a bottle of 75/25 inert gas, gauges, welders, and a mad scientist streak in me. If I can scrounge a spare steel injector line, I'll fab up a pop tester tomorrow.

I'm wondering if they shipped the rebuilt IP with a preservative in it that may have caused the injectors to lock up.

 

[Diesel JD]

I've got a spare small O2 tank, a bottle of 75/25 inert gas, gauges, welders, and a mad scientist streak in me. If I can scrounge a spare steel injector line, I'll fab up a pop tester tomorrow.

I'm wondering if they shipped the rebuilt IP with a preservative in it that may have caused the injectors to lock up.

You're supposed to be able to make your own out of a bottle jack or grease gun. The problem I had and why mine does not work is that I can't get it to hold more than 100-200PSI, not enough to pop the worst injector out there. I have some more free time + some welding equipment now so maybe soon I'll figure it out. until then good luck with yours. I bet you do figure it out. Don't get frustrated with these IDIs they are stupid simple compared to what you work on for a living, you don't want to outsmart yourself. Lots of solid redneck data here from the school of hard knocks. They do have some quirks and there are a couple tricks to getting them to run right, plus doing this IP swap can be a logistical nightmare to get everything back where it needs to be.

 

[DOE-SST]

I'm thinking...

small heavy steel O2 bottle, good for 2500psi, put a T fitting on it, one end connects to a 2800psi bottle of argon, other end connects to a regulator/gauge, and that connects to the injector.

add half a gallon of diesel to bottle, add 2200 psi argon, close off hose to argon bottle. Invert bottle of diesel, open regulator til fuel flows, read gauge and examine spray pattern.










Oh, wait,

I forgot the "hold mah beer an watch this..."



I'll have a 1/2 inch steel plate between me and the bottle.



Now, if y'all see any problems with this setup, speak up now. Ya wouldn't want me doing somthin really stupid or dangerous,


would ya?

 

[DeepRoots]

http://emedicine.medscape.com/article/1241999-media

there ya go! be careful.... ohh and btw a set of injectors costs like $200 or so.

 

[DOE-SST]

You're supposed to be able to make your own out of a bottle jack or grease gun. The problem I had and why mine does not work is that I can't get it to hold more than 100-200PSI, not enough to pop the worst injector out there. I have some more free time + some welding equipment now so maybe soon I'll figure it out. until then good luck with yours. I bet you do figure it out. Don't get frustrated with these IDIs they are stupid simple compared to what you work on for a living, you don't want to outsmart yourself. Lots of solid redneck data here from the school of hard knocks. They do have some quirks and there are a couple tricks to getting them to run right, plus doing this IP swap can be a logistical nightmare to get everything back where it needs to be.

Yeah,

LOTS of good technical info here. Info that I am not finding from Chiltons or Haynes manuals. Just the opposite of aircraft maintenance.


If I ever win the lottery, some of you guys are gonna find new trucks under your Christmas trees.

 

[DOE-SST]

http://emedicine.medscape.com/article/1241999-media

there ya go! be careful.... ohh and btw a set of injectors costs like $200 or so.

Thanks,

I WILL look through that site carefully. Seen plenty of workplace accidents myself, and have previously done the whole 18hr ER/Trauma center, 2-week ICU shtick.

You make a good point, and I'll be double checking the strength of everything in the setup. I have fabricated high-pressure hose for aircraft many times before.


Buying new injectors is plan B. These appear dirt simple, and I want to test/reset them myself, just for the knowledge gained. One injector needle had substantial water staining, and cleaning it with scotchbrite may have altered it's shape. Some of the shims mic out to .002, so I expect it will take several tries to get each nozzle to 1800psi +/- 200. I hope those are factory specs.

 

[DeepRoots]

doe,
I'm offshore working here in the gulf at the moment (be home in 10-15 days).
If you are interested I have a set of Delphi injectors I can send ya....
Just name your price.
spare parts and whatnot.
They were purchased new, gave a horrible engine knock after 5,000miles.
I found a set of stanadynes that were brand new and tested for $80 so I threw them in when I did the moose pump.

Anyway, probably only one of the injectors is bad, but I was in business at the time and didn't have the time for downtime.

Drew