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1989 110 pickup
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Discussion Starter · #1 ·
1989 110. 3.5 V8 with stock SU carbs. Until just recently, this truck has run flawlessly. Always started easily, idled well, no smoke and no leaks.
A couple days ago it stalled at idle. It started back up after a couple attempts, but was idling very rough and seemed to be misfiring. It has progressively gotten worse to the point it won't idle without the choke engaged or using the throttle. There's also a lot of blue smoke from the exhaust.

I haven't had time to do much diagnosing. I pulled one spark plug and it was pretty black. I'll either clean & re-gap all 8, or maybe just replace them. I also pulled the air filter and it is in good shape. Vacuum lines look good. So do plug wires, cap, rotor, etc.

Rough running / rough idle I could attribute to a spark or fuel issue, or maybe a vacuum leak, and troubleshooting is pretty straightforward. What I don't understand is where the blue smoke is coming from. Could this be clogged flame traps/air-control valve or related hoses?

Coincidentally, this all started about 30 miles after I filled the tank with 90-octane non-ethanol gas. I put on a new fuel filter and added a can of Seafoam. It seemed to run a little better for a while, but that didn't last.

I'm almost embarrassed to be asking this question. Years ago I did all the maintenance on my cars, but for a long time I've had modern vehicles that either required little maintenance or a maintenance skill set well beyond mine, so I've gotten a little rusty.

Thanks in advance for any suggestions. Gotta get this resolved before URE!
 

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I don’t know what carb you are using, but what you’re describing happened to me often with KZ1 4 stroke Kawasaki’s when a float stuck or an idle jet came loose in the carb. Sounds like something happened to your carb, to me. Most my **** is IP pumps or FI, so no carbs except on my 2-strokes…
 

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Searching "blue smoke after seafoam" does yield some results on DuckDuckGo. Maybe give it a looksee?
 

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1989 110 pickup
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46 Posts
Discussion Starter · #4 ·
I forgot to mention it's also running a little rough under load.
Like I said before, this happened all of a sudden, so it makes me think it's not something like rings or valve seals. Somebody correct me if I'm wrong?
 

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1989 110 pickup
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Discussion Starter · #5 ·
Searching "blue smoke after seafoam" does yield some results on DuckDuckGo. Maybe give it a looksee?
Thanks, I did do that. Today I got a mixture of some white and some blue, so maybe some of what I was seeing is the Seafoam burning off. Still doesn't explain the rough running, but maybe the two aren't related.
 

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If spark is consistent and timing is good , probably just a clogged carb or suken float
 

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1989 110 pickup
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46 Posts
Discussion Starter · #7 ·
If spark is consistent and timing is good , probably just a clogged carb or suken float
Would that cause blue smoke? I always thought blue = oil.
 

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You have to start somewhere? Blue does normally mean oil yes.

Checking timing and spark and then cleaning the carbs is all on the exterior of the motor and easy to do
 

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1989 110 pickup
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Discussion Starter · #9 ·
You have to start somewhere? Blue does normally mean oil yes.

Checking timing and spark and then cleaning the carbs is all on the exterior of the motor and easy to do
OK, that's the plan. I was looking for a shortcut, but I guess there's no substitute to going back to the basics.
I'll report back.
 

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Please post an excruciatingly detailed step-by-step photo thread of your SU carb cleaning endeavor.
 
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