I have searched some of the other threads but none seam to match my scenario. I started my 97' psd after work, started fine no problem, after 5 sec. or so a loud thump started and would shake the whole truck. I left at idel and could feel and smell exhaust through the vent in front of the air cleaner. I had disconnected my ebpv about 6 mos ago. I shut the truck off thinking the valve was stuck, restarted same problem, loud thumping like the piston was smacking a valve.(really hard and loud) I drove the truck home felt sluggish at low rpm's and I could hear it "dieseling" in the exhaust. Truck starts fine but really rough idle now. I replugged in the ebpv today, and let idle for 10 mins to bring up engine temp. no change. Runs better at higher rpm's but still rough. Exhaust used to be grey smoke, however almost no smoke now. Injectors re-built just over a year ago, any help would be appreciated. I live in Montana so we have been cold the last few weeks 5-28 degrees low to high. The truck has 195,000. thank you

 

Check all of your Valve cover connections. Make sure there are no burnt pins or loose connections. Mine acted similar when the pins where loose in the connectors after I replaced one of the VC plugs. Basically was running on 6 cylinders.

 

That doesn't sound good. Try taking the oil filler cap off and flipping it over and setting it back on top of the fill hole. If it blows the cap off that is not a good sign, but if it just kinda vibrates around and then slides off, you're not having an excessive amount of blow by. Another thing you can try if you have access to an IR thermometer is to start the truck up cold and shoot the exhaust manifolds right outside of each exhaust port. If you have one or two that are considerably cooler than the rest, you have an issue of some kind with that cylinder.

I would second looking at the valve cover connectors as well as it sounds like you may be missing on a cylinder or two. Worse come to worse you may need to pull the valve covers and start the truck with the covers off to see if all 8 injectors are spitting oil.

Report back and let us know what you have found as you go and we will help you get this thing running again. Hah, hopefully you have somewhere to work on this thing inside, if you live in MT! I'm getting a chill just thinking about working on it outside!

 

checked all pins and connections they are all good, not burned or broken. when i took the rubber boot off just before the turbo, i noticed oil not alot but some inside the boot and a small trace on the turbo body just before the fins? took the oil cap off and set over hole, no blow off just vibrated off. no more thumping just really rough idle. I pressed the peddle and increased rpm to about 1500 and runs normal, however when I let off the pedal it seems to miss then back to rough idle.

 

The oil in the intake boot is normal as long as it isn't excessive. There is a CCV (crank case vent) that lets the engine breathe and it empties through the little doghouse on the driver side valve cover and back into the aluminum intake elbow. That way you don't see the vapors and have to smell the stink.

Did you check the wiring harnesses under the valve covers as well or just the 4 on the outside?

Have you by chance tried checking the condition of your fuel filter? A clogged fuel filter will make these truck run like poo. While you have the fuel filter out, cut the fuzz off the end of a q-tip and use the stick to gently clean and scape the crud out of the fuel pressure regulator (FPR) screen. It is inside the little (1/2" or so diameter) hole in the driver side of the fuel bowl. That thing being clogged up can affect the way the truck runs. After you're done, it might not hurt to check the fuel pressure. For this you will need a cheap-o, stick style tire gauge. On the driver side of the fuel bowl on the FPR there is a small black plastic cap that resembles a tire valve stem cap (actually that's pretty much what it is). Remove that cap and with the engine idling, use your cheap-o gauge to check the fuel pressure at the Schraeder valve that is behind the cap you just removed. Be careful as it may spray some diesel while you're fooling with it (have a rag handy). You're looking for somewhere around 50-60 PSI. Anything below that and there is an issue with the fuel system.

 

going to change filter sent wife to get one. checked fuel pressure at 35 psi consistent. cleaned fuel port screen on driver side of fuel bowl with q-tip stick, very dirty. Pulled filter and needs to be changed will give update after installed.

 

new filter, cleaned port in fuel bowl checked fuel pressure 35psi.

 

Run a can of seafoam through it. Sounds fuel related. Pull the filter again and fill the bowl with it. Start and let it run for a min. Shut off for 15 and then go for a good hard drive. See if it helps.

 

Ok, well if you have a new fuel filter in it, and cleaned the FPR screen and you're still only seeing 35 PSI of fuel pressure with the engine running, you either need to shim the FPR, or your fuel pump is shot.

Here is a link on how to shim the fuel pressure regulator (FPR).

Try that first, and if that doesn't do it, then there's a good chance you need a fuel pump.

 

A little more truck history wouldn't hurt, like mods and other stuff you have done, is it stick or auto, still got the DMF?

 

What about the CPS? If its making loud noise then the timing might really be off. Loud noise doesn't come form fuel problems, does it?

 

Glenn when my pump was on it's last leg I had a loud injector knock lime two hammers hitting together

 

check the spring in the FPR to make sure it's not broking

 

stock, no mods, 5spd. . the hammer striking description is very accurate. I will check the spring and see if it is broken. Thank you all for the help I appreciate this forum, everyone so helpful, with great pics and information.

 

I didn't realize that Mike. Not knowing this would make you think that your motor was on its last leg. Now you need two hammers in your avatar!