first a fish bite then black smoke

[pitsingerk]

A little background, the Suburban has approx. 265k miles, new injectors and pmd within the last 5000 miles. The injection pump was replaced by the previous owner at around 150-160k, lift pump was replaced 10k miles ago, fuel filter about 2 months ago. Over the last month, the truck would from what I would take from other posts, fishbite, kind of stutter like it's missing, or running out of fuel. I've been extremely busy so I parked it and have been riding the Harley and driving my beater plow truck. I've been searching for possible fixs here on the forum. I saw where most people take out the filter on top of the pump and cured some issues. Tonight when I got home, I pulled the truck in the garage, it would barely run, almost didn't make it in the garage. I pulled off the upper plenum, removed the filter and put it back together. I fired it up and it ran great. I took it down the road for a test drive and was getting on it, looking back in the mirror I see I'm just roalling black smoke. The truck is running strong, pulling hard, no missing, nothing but the black smoke, not a little, I mean blacking out the sky behind me. This didn't happen before I parked it. What the hell can be going on here.

 

[matuva]

You look like lacking boost.

Have a look at the actuator on the side of your turbo.
Engine off, the rod is down
Once you start up, the rod goes up, and you can hardly move it by hand.

Usually the culprits are failed boost solenoid,the one with the green dot on the bank of solenoids, rear of engine, driver side; or broken/disconnected vacuum line; or failed vacuum pump.

 

[pitsingerk]

Lack of boost was the first thing I thought of. With the truck running, I pulled the vacuum line off and watched the rod go down, put my finger over the hose and could feel the vacuum. I played with it, putting on, taking it off, watching the rod go up and down, and then no vacuum at the hose, rod didn't move. I thought that was strange, I went around and revved the truck up to see if I can hear the whistle, nothing at first, took the air cleaner off, and I could hear a slight whistle. I figured this truck never really did whistle like my powerstrokes so I left it as good when I went back around and the rod was back up and pulling off the hose I had vacuum again. I know it has a switch, figured it was off when I could not feel anything earlier. The vacuum pump was replaced last spring so I would assume it is good still.

 

[matuva]

"switch" is the solenoid. It can be shot or it can be just the electric connector to the solenoid. I found some with the wire broken or close, which caused the solenoid to shut erracticely.

Check you harness/connector, worth a try

 

[pitsingerk]

Went back out and started the truck, no vacuum to the waste gate. Pulled the connector out of the solenoid and tested to ensure I'm getting power to it and I was. I plugged it back in and the solenoid started chattering, went around to the turbo and the wastegate was actuated. Took it for a drive, got a little smoke when I got on it hard, rest of the ride was normal. I'm going to pick up a new solenoid in the morning. Thanks for the help. At this point I'm still hoping that the fishbite problem is gone due to taking out the filter. It seems to damn simple just to remove that and not have the problem.

 

[matuva]

Hope it is the fix.

Some of us do delete the vacuum actuator and replace it with a mechanical controler (aka turbo master)... or upgrade to a non-wastgated turbo

 

[pitsingerk]

With just spending the money on the new vacuum pump, then the money for the turbo master, new belt, gauges (on the wish list anyway), it's just not feasable to make the change right now. I'd rather spend the money on an exhaust and new injection pump first.

 

[minisub]

Mine started doing similar things and I still had a good vacuum pump. If I recall, I bypassed the solenoid and went straight from the pump to the actuator as a test. This was after replacing the solenoid with no improvement. Concluded that the issue was in the PCM. Ended up running it that way until the pump died and went with a spring until the whole truck died...