Hi all,

New here to the forums. I've got a 83 K5 Blazer diesel that's idling rough and smoking pretty good.

I bought it off a guy and drove it home (500 miles). It was hard starting but it ran pretty good once we got the kinks worked out (it blew the fuel pump on mile 50 ha). Drove great the rest of the way.

When I got back I stuck it in the shop to start restoring it. The mechanic mentioned it was going to need a new injector pump soon so I went ahead and had him put a new one in.

With the new pump it's still hard starting, and now idles really rough and smokes. Run's fine when in gear though. Seems to have just as much acceleration as it did before, just runs rough when idling and smokes a ton.

Not sure why it's so hard starting either. Anyway, any help would be great. I'm new to the diesels and not much of a mechanic.

 

Likely needs injectors overhauled or replaced?
Glow plugs working?

 

Sounds good. I've got some new injectors that came with the truck. I'm guessing with some youtube videos and some tools I could test the old injectors?

I'm pretty green with engines. I've got a diagnostic appointment in 10 days, just antsy to fix the problems.

 

You could build an injector pop tester to check the pop off pressre the injectors release at or see the spray pattern,but it would probably be easier and cheaper to get the local farm repair or diesel shop to test them.

 

I recently purchased an 83 half-ton k1500. This truck had been sitting more or less for 3 years, after i put a new starter in it i finally got it fired up. it had a very rough idle sounded like it had a miss and smoked like a blown head gasket. After an oil change, adding fresh fuel to the tank with some injector cleaner/de-geller it started to get better. I changed both fuel filters along with priming with some sea foam, ran about 15 gallons of fuel with the additive to it and the miss was almost gone along with the smoking. I then noticed the driver side exhaust was plugged, so I cut the muffler off and WOW! what a difference. my advice is take note of my issues and also check the EGR see if the flap things (not sure what its called) just after your manifolds see if the happen to be stuck closed (they are vacuum controlled so i would disconnect them (they stay open without vacuum pressure, or should) and in the intake is the EGR valve that opens (can't miss it big cylinder in the center of the intake) make sure that is shut as well (also vacuum controlled).

 

Good stuff guys, thanks. I've got new muffler's on it but yeah it's smoking pretty good on the start, and idling really rough. Sounds like a similar problem.

What additive did you use?

 

I used CRC Diesel, Fuel treatment Injector cleaner with de-geller, I got it from Carquest but other places should have it too. I mixed it a little heavy because the truck had been sitting for 3 years. Also change the fuel filters and fill them with fuel and SeaFoam. I'm not sure what is right and wrong but I filled it about 1/3 SeaFoam 2/3 off-road fuel and it helped.