6.9 W/Bad Injection pump?

[Greaser67]

I have a 1985 F250 ext cab with an early style Banks turbo (square air filter housing). It only sees about 10,000 a year and currently has 105,000 miles on it.

About a year ago I noticed it was blowing blue smoke on cold starts, then progressed to blue smoke on hot starts. By the time it was blowing blue smoke on hot starts it was winter and I didn't want to mess with cleaning injectors so I just did a fuel system flush. I filled a new filter with Liquid Moly injector cleaner and ran 3 more cans of it thru a recirculating loop of the filter, IP and injectors. That smoothed out the rough idle but did nothing for the blue smoke.

About a month ago I noticed it starting to be down on power a little and would blow blue smoke until it warmed up. I never really work it hard unless I'm pulling my car trailer. Well last week I'm driving home and it seems to be real low on power, and declining fast. Finally got to the point it stalled. I called for a tow, but it did restart and I was able to idle home.

I found the Fuel filter half full and the lift pump arm had a lot of slop in it, bad lift pump. Replaced the lift pump. Still blows blue smoke and won't rev over 2,000 while driving, low on power.

I am wondering did I hurt the IP driving 6 miles while starving it for fuel?

I have read that 100,000 miles is about the service limit for these pumps and injectors, any truth to that?

I am leaning toward replacement MOOSE injectors and a Baby pump. Not sure about going up to the Junior pump.

Any input you can give would be appreciated.

Thanks

 

[Kdo58]

If the fuel filter is half full it's not the injection pump.

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[IDIBOBS]

Yes Injection pumps and injectors life expectancy is 100-150k miles and the more they sit the less the milage is. Diesel should not sit around it’s goes bad and varnishes things and ruins them. this is the reason consumer RVs are not diesel they sit 90% of the time. A basic stock pump timed correctly and tuned for your turbo and stick injectors should still get you all the power you need

 

[Greaser67]

If the fuel filter is half full it's not the injection pump.

You must be registered for see images attach

I like the troubleshooting card!

My fuel filter was half full before I changed the lift pump (checked 2 different times), with the new lift pump fuel is up to the bottom thread of the fuel filter. It still smokes and is low on power.


"Plugged Fuel Suction Line or Filter"- I removed fuel suction lines from the water trap on the firewall. Fuel line from water trap to lift pump is clear, purged it with compressed air and could easily blow through it. Fuel line from water separator to tank is clear. Extended this line to a bucket on the ground and fuel easily siphoned, ran good and constant. Hard line from lift pump to filter housing is clear, easily blew through it. New filter blows hard, just like old filter (500 miles), normal I think?

"Air Leaks, Suction Side Fuel Line"-The fuel return line to tank on filter housing is clear, I can see no air bubbles passing through it.

"Injection Pump Timing Out of Adjustment"-It's possible but I have not messed with pump or timing since I owned it, 10 years and 40,000 miles. This problem came on somewhat quick, over 100 miles.

When I removed the fuel filter housing return line it sprays fuel from the nipple. I don't think my current problem is between the tank and fuel filter.

Cold start (75 deg here), starts easy, very rough idle, white/blue smoke.

I'm leaning towards multiple bad injectors dribbling or bad spray pattern. But I'm scared the IP is damaged due to not getting all the fuel it wanted when lift pump was bad and maybe that's causing the misfire on multiple cylinders and that shows up as blue smoke and low power.

I miss spoke on yearly mileage in original post, 1,000 a year.

 

[Greaser67]

A basic stock pump timed correctly and tuned for your turbo and stick injectors should still get you all the power you need

I would agree with that. When it ran good acceleration was very good. Trailering another diesel truck once it was all it could do to maintain 55 mph in 4th, 3rd on hills. 4.10 gears

 

[IDIBRONCO]

Before you go out and buy anything new, try advancing your pump timing a little bit and let us know what happens.

 

[Greaser67]

Been a busy day, didn't get the pump pry tool made yet or the timing advanced.

But I had an idea that I could do a POP test on the injectors while they're installed on the truck. My idea is to use a grease gun (new) to build the needed pressure, but not sure if the gun will handle diesel fuel though. My style gun will make 7500 psi. I worked industrial maintenance for 25 years and I would use a grease gun loaded with 10wt oil to clear grease channels and zerks all the time. It would dead head the gun if it didn't blow the jam, so no leakage.

Would doing a pop test with 10wt oil hurt anything? It should still pop at the same pressure but just flow slower through the injector orifice once it pops.
Correct?

 

[IDIBRONCO]

IO have no idea about the 10w oil. I do want to say that you need to make sure that you remove the glow plugs, then unplug the FSS, and crank the engine over several times to blow all of the extra fluid from your test out of the cylinders. BEFORE you try to start the engine!

 

[Black dawg]

Pop testing with a more viscous fluid is pointless. As is doing it with the injectors installed unless you have tested many and know what to feel for

I have heard of guys using diesel in a grease gun....

 

[Greaser67]

Well its been busy around my place lately but I did find time to work on the truck the last 2 days.

I've had the injectors out 3 more times, they keep spraying bad patterns or leaking. The last time I pulled them they all popped and sprayed good.

Did a compression check, it was a Harbor Freight POS, but I got results that I'm ok with considering. 420-520 psi on all, the schrader valve in the adapter leaks back inconsistently.

Seems like it starts good, is smooth for a couple seconds then runs rough and smokes.

Advanced the timing double the thickness of the line, idles smoother, not great, still smokes.

It seems to idle quieter???? I don't notice the sharp knocks when each cylinder fires. Not sure if its been that way since the lift pump went out or since I advanced the timing. I'll try advancing the timing a little more as time permits. And no I don't have a timing kit yet.

 

[chickenpot]

i wouldnt play with the timing until you have a meter on it. what are the injectors popping at? as long as they all match within ~50 psi then time with the meter accordingly. dont pop them on the truck, doesnt sound fruitful. you can test them with 10w on the bench though. something also to note about the injection pumps is the timing at idle and the dynamic timing curve provided by the cam plate/arm are affected directly by the transfer pump fuel pressure inside the pump housing, which is primarily affected by the supply pressure from the lift pump. the pressure the injector pops at also affects timing. need a non leaky set of injectors that all pop within 1800-+50psi(~1500 for used nozzles), 5 psi of supply pressure, dynamic timing set at 8.5 btdc +-2 at 2000 rpm(with a meter, essential)

 

[Greaser67]

All injectors pop at 1800-1850 with diesel.

I advanced the pump some more, 1/8" CC on timing marks, started right up, ran smooth, engine was a little noisier ( normal knocking sound) and quit smoking after a couple seconds.

Looks like a new pump and injectors are in its future.

 

[IDIBOBS]

Sounds like You have it running right.

 

[IDIBRONCO]

Glad to hear it.

 

[Greaser67]

Found the culprit for having to advance the pump to make it run and not smoke. The Cold Start Advance check valve was stuck and not fully relieving pump pressure to allow the the advance mechanism to work. I found a GM/Stanadyne manual that explained the pump operation alot better than the other manuals I seen.

I didn't even realize that brass fitting on top of the pumps return line was a check valve, I assumed the Cold Start solenoids plunger did the sealing. I held that fitting up to light to see if it was clear/plugged several times, seen light thru it so it wasn't plugged right?

WRONG!!! The check ball is clear and lets light shine thru. The only reason I caught it was I was going thru 2 other pumps and 1 pumps brass fitting was like mine, could see light thru it, the other pumps fitting had a brass or steel ball. Couldn't see light thru that one. BINGO.

I was minutes away from giving up and buying a Moose pump and injector set. Not even sure if the new pump would have came with the check valve either. Runs great now.