Need Advice on M1008 Phantom Noise/Smoke/Fuel Problem

[AFC1]

Utterly disgusted and need some advice from the experts on here. I have a 1986 M1008 that I bought with 37,000 original miles. Changed gear ratios to 4.10, put tinted glass in it- used it every day until I hit 79,955 miles. Never had a single problem, no complaints whatsoever. Around April 2013, pulled the truck off of the road due to body rust and felt it was time for a restoration. I put new injection pump, water pump, oil pump, injectors, glow plugs, SM465/NP205 combo in the truck. Bled the fuel system, engine fired up after seemingly a half a turn. Was happier than anything. Body work was then completed and paint and final assembly followed. After about 800 miles of using the truck with no problems, I noticed that the injector lines on #3 and #5 were leaking slightly at the injectors. Injector lines were original and after retightening them did not stop the leaks, I figured I should replace them. Truck sat until I could track down original GM injection lines and then I replaced all of them. After replacing the lines, truck refused to start. Truck finally started and ran poorly. Figured I had air in the system and tried bleeding the injectors. Truck continued to run poorly-it was smoking out of the right bank and now had a knocking sound that came and went. The knocking sound always produced blue smoke out of the right tailpipe. I would be driving down the road at 55 MPH and all of a sudden the sound would come out of nowhere and here comes the smoke. Throttling up sometimes made it go away, sometimes not. Okay, I figured I must have gotten a piece of dirt or something in 2,4,6 or 8 injector. Ran injector cleaner through it to no avail. Parked truck and bought 4 new injectors even though these only had 800 miles on them. Changed all right side injectors. Truck fired right up with no problems this time. Drove the truck 6 miles with no noise, no smoke, ran perfectly. At mile 6.5- going 30 MPH here comes the rapping noise out of nowhere and the right side is loading up again producing puffs of blue smoke out of the right side tailpipe. I must admit the noise is much quieter and smoke is less visible, but still there. Do I have some sort of intake valve problem? Looking now it appears I have a slight leak underneath the intake manifold- which I now have to remove for the fourth time. I am literally tearing my hair out. A problem that comes and goes like this is crazy to diagnose. If I had known this was going to be the case, I would have driven the truck all rotted out and just junked it when I was done. This complete restoration has taken 18 months and I now have a truck I no longer trust and am completely frustrated. Has this ever happened to anybody out there? Broken valve spring? Took the time and effort to put a 73-80 nose on this truck with the original 6.2L, don't even want to drive this thing anymore. I will listen to any ideas.....

 

[cucvrus]

I am thinking injector pump. I know I always go there. But that is what I am thinking on my long distance diagnosis.

 

[AFC1]

I am thinking injector pump. I know I always go there. But that is what I am thinking on my long distance diagnosis.

That is what I originally thought too, but blocked it out due to the fortune I paid for it. I guess it is only as good as the guy rebuilding it....thanks for your response. May be pulling this one off again in the long run.

 

[dependable]

Seems in the original post, maybe some contamination or particles got in the injector lines. Injector cleaner will not fix this. If that is the problem, it may work itself though if you are lucky, but it is easy to mess up injectors with contamination. A small bit of sand, large bit of dust, the tolerances are pretty tight.

 

[Stonepicker1]

Are you sure you have the injector lines hooked up correctly from the pump to the correct injector ?

 

[FMJ]

Ok, I just solved this problem on my 1028A3, the truck was very hard to start, smoked a ton before it started. The problem is a leak at the fuel filter housing, between the filter and the housing, I installed o-rings on the hard lines on the housing to make a good seal between the fuel filter housing and the filter itself, problem gone, no more smoke, no more rattle, etc. . . I can post a pic if necessary.

 

[AFC1]

Ok, I just solved this problem on my 1028A3, the truck was very hard to start, smoked a ton before it started. The problem is a leak at the fuel filter housing, between the filter and the housing, I installed o-rings on the hard lines on the housing to make a good seal between the fuel filter housing and the filter itself, problem gone, no more smoke, no more rattle, etc. . . I can post a pic if necessary.

I hope this is it. I am going to change out the entire fuel filter housing as it is the original unit and I planned ahead and bought a new GM housing last year. Once I do that, I will check how the filter seals against the new housing. Thanks so much, plan on attacking it this weekend.

 

[AFC1]

I hope this is it. I am going to change out the entire fuel filter housing as it is the original unit and I planned ahead and bought a new GM housing last year. Once I do that, I will check how the filter seals against the new housing. Thanks so much, plan on attacking it this weekend.

Put a brand new GM fuel filter housing on and gave it a shot. Smoke out of RS and engine rattle is significantly worse. Grew enraged and held throttle at 3000 RPM for 5 minutes hoping engine would blow up and save me all of this aggravation. Unfortunately it didn't and now I have to continue trying to fix this issue. One thing I confirm though is that I definitely have a drip at the back of the injection pump, so off comes the intake manifold again.

 

[cucvrus]

That small drip/leak could hold the key to your problem. This is a mechanical thing that has no feelings. Control the anger and use the energy to solve the problem. Not make it worse. Good Luck. I am sure it is a simple thing.

 

[llong66]

Could it be that you got a bad injector? is the noise your hearing like a bent rocker/push rod in a gasser or just a light tap? If just a light tap, I would look at injectors. What type did you buy, new or rebuilt and what brad?

 

[AFC1]

The first batch of injectors were brand new GM replacements. No problems whatsoever. 800+ miles without a hitch other than a dripping 3 and 5 cylinder injector line at the injectors. After replacing all 8 injector lines, the noise coming from the engine sounds similar to the pinging/ rattle sound an older gasser makes when you hit passing gear on the highway while running low octane gasoline. After replacing the injector lines I also thought I had a bad/ contaminated injector on cylinder 2,4,6 or 8. I actually thought that a piece of dirt or rust accidentally got into one of the injectors. This time around I replaced all RS injectors with new Echlin injectors from NAPA. Started the truck up and it ran perfectly. Drove it 6 miles and never had any smoke or engine rattle whatsoever. At 6.5 miles going about 30, the noise abruptly started, but it was very faint. Only lasted about 1.5 seconds. Went away with my not doing anything at all- I didn't even let up on the throttle. Drove another flawless 4 or 5 miles and the noise/smoke came back again for 3 seconds or so and left again. This is not a problem that is consistent at all. It disappears as suddenly as it appears. That was the case until I changed the fuel filter housing. Upon start up with the new GM unit, this problem has returned in the intensity it had prior to changing the RS injectors. Knocking/ blue smoke even at idle- constant for 10-15 seconds, goes away for 30 seconds, comes back again. LS tailpipe shows no smoke at all- runs fine. This problem is definitely fuel related. Have no idea how changing the fuel filter housing has changed this problem so dramatically. I keep putting new parts on this truck that are seemingly detrimental to getting it to run better. This thing is crazy.