Inexorable Blue Smoke

VMacKenzie

VMacKenzie

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Joined
Dec 9, 2007
Messages
625
Posted about this a couple years ago but still got a '98 12v that blows blue smoke, way more than it should. Really has the cold morning stink until it completely warms up and even then the odor is very strong. You'd think it had 5x16 injectors and lazer cuts but it just has 50hp DDP sticks and stock DVs. I have done a number of things to combat it mostly to no avail.

When warm it does not haze at all when idling, totally clean exhaust, but the moment you start touching the throttle even lightly the blue smoke starts. Roll into it more and the blue smoke gets heavier, then around 10-12psi boost it changes to gray.

I have completely gone over the fuel system from dropping the fuel tank & inspect the pickup to servicing the prefilter, checking fuel pressure, etc. I ran a test and clearly determined it's not pulling air anywhere. Have tried 3-4 sets of injectors (stock ones, Bosch 300s, DDP 50s), even replaced the injection pump, replaced the overflow valve twice, replaced the lift pump, set the timing and set it again (16 degrees), etc. etc.

Recently I picked up a 215 pump that had been gone through by a shop in Spokane that is supposedly a reputable shop. It cleared the smoke considerably but 800 miles later BAM! Smoke pig again. Really weird. Happened in the middle of a tank of fuel, didn't run any different, just started smoking worse than ever. Next I'm trying another set of injectors and double checking the timing incase it slipped (I doubt it though, runs smooth if you rev it right after starting it, engine clatter says it's at least 15-16 degrees).

Also I'm pretty sure the compression is good, blowby is very minimal, never leaves a spot in the driveway, underside is clean, no oil leaks, runs smooth.

Any thoughts/suggestions would be appreciated. . .been a mystifying frustrating issue. Love my truck a bunch, would really like to solve this problem. Both 12-valve rigs I've owned have had stubborn challenging problems . . . if it wasn't a big job I'd dump the motor in a heartbeat and drop a 24v or common rail in there!
 
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VMacKenzie said:
Posted about this a couple years ago but still got a '98 12v that blows blue smoke, way more than it should. Really has the cold morning stink until it completely warms up and even then the odor is very strong. You'd think it had 5x16 injectors and lazer cuts but it just has 50hp DDP sticks and stock DVs. I have done a number of things to combat it mostly to no avail.

When warm it does not haze at all when idling, totally clean exhaust, but the moment you start touching the throttle even lightly the blue smoke starts. Roll into it more and the blue smoke gets heavier, then around 10-12psi boost it changes to gray.

I have completely gone over the fuel system from dropping the fuel tank & inspect the pickup to servicing the prefilter, checking fuel pressure, etc. I ran a test and clearly determined it's not pulling air anywhere. Have tried 3-4 sets of injectors (stock ones, Bosch 300s, DDP 50s), even replaced the injection pump, replaced the overflow valve twice, replaced the lift pump, set the timing and set it again (16 degrees), etc. etc.

Recently I picked up a 215 pump that had been gone through by a shop in Spokane that is supposedly a reputable shop. It cleared the smoke considerably but 800 miles later BAM! Smoke pig again. Really weird. Happened in the middle of a tank of fuel, didn't run any different, just started smoking worse than ever. Next I'm trying another set of injectors and double checking the timing incase it slipped (I doubt it though, runs smooth if you rev it right after starting it, engine clatter says it's at least 15-16 degrees).

Also I'm pretty sure the compression is good, blowby is very minimal, never leaves a spot in the driveway, underside is clean, no oil leaks, runs smooth.

Any thoughts/suggestions would be appreciated. . .been a mystifying frustrating issue. Love my truck a bunch, would really like to solve this problem. Both 12-valve rigs I've owned have had stubborn challenging problems . . . if it wasn't a big job I'd dump the motor in a heartbeat and drop a 24v or common rail in there!
Click to expand...
Why not try injectors that are not DDP?
 
Sounds like a weak/sticking ring to me allowing oil into the cylander or a scored cylander wall. Other option could be a leaking turbo seal but I think the first two options are more likely. After thought but have you ever reset the valve lash? An over tight valve may be holding the valve off the seat just enough to get some oil in there but I would think it would run a little rough. Have you tried running a thicker oil to see if the blue smoke output changes?
 
Not your blue smoke problem, but if you haven't had your pop off pressures checked in a a couple of years they will be low and contribute to haze. In a year(6-8k miles) mine will drop down below acceptable range.

RonA
 
DDP injectors do that.
I have a very unhappy customer with the same scenario. Blue smoke, stinking exhaust, and crappy fuel mileage. Did I mention this all started about a year after I put a set of 50hp ddp injectors in?
 
Thanks for the input guys. I am looking at picking up injectors from SDX or CPP, been reading about them but not sure which way to go. I know Weston says stick with 5-hole for the 12-valve but sounds like a couple 7-hole options look promising too. I read to go with 145 spray pattern, thinking 5x12s, or on a 7-hole go with 7x09 which one vendor offers or 7x10 but not sure if those have the right spray angle.

Since the truck goes at least 3-4k miles before using a quart of oil I'm pretty sure all the blue smoke is fuel, it stinks like raw fuel. I don't think it's valve stem seals or turbo or rings. Engine has 209,000 on it and never been opened up.

Vaughn
 
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DDP's should pop at 4000 psi, I have a set of 5x14's in my 98' but never had anything but good luck with them.

Jim
 
I like to run mine around 280-285 bar. When they go below 265 they start hazing.
If you don't have someone local to set them, I'd be happy to do it for you n/c.
RonA
 
VMacKenzie said:
Thanks for the input guys. I am looking at picking up injectors from SDX or CPP, been reading about them but not sure which way to go. I know Weston says stick with 5-hole for the 12-valve but sounds like a couple 7-hole options look promising too. I read to go with 145 spray pattern, thinking 5x12s, or on a 7-hole go with 7x09 which one vendor offers or 7x10 but not sure if those have the right spray angle.

Since the truck goes at least 3-4k miles before using a quart of oil I'm pretty sure all the blue smoke is fuel, it stinks like raw fuel. I don't think it's valve stem seals or turbo or rings. Engine has 209,000 on it and never been opened up.

Vaughn
Click to expand...
Id get with weston or sdx for injectors.
 
RonA said:
I like to run mine around 280-285 bar. When they go below 265 they start hazing.
If you don't have someone local to set them, I'd be happy to do it for you n/c.
RonA
Click to expand...

That is good info Ron, and thanks for the offer. I got a PM from Weston and he is going to fix me up :cool:
 
OK finally got my SDXs and installed them over the weekend. Went with 5x12s which ended up being a bit less power than the DDPs but that's OK. Runs much smoother and it totally cleared up the slight miss when the TC locks up. They drive great and I'm impressed.

BUT. . . still smokes too much, apparently it's not an injector issue. It smokes a little differently now in that it hazes noticeably at idle, but less smoke under light throttle. The DDPs had no idle haze but rolled out a lot of gray/blue smoke as soon as you started stepping on the throttle. The smoke level is almost acceptable to me but maybe I just exptect too much out of a 12-valve. My only guess is appartenly I swapped out one hohum P7100 for another less than perfect one, but I'm done fighting with it and I'm planning to sell the truck and get a 24-valve anyway. Found a pretty nice '99 Club Cab SLT 5-speed I may pick up.

Vaughn
 
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