86 Suburban- minor engine issues

[geocrasher]

Howdy all,

Well my 87 Suburban died last year, and then the car I got to replace that got hit and totaled. So, I got another Suburban, as the title says, a 1986. This time its carbureted, of course since the FI didn't start until 87. Its a 350 with a TH400/NP208 and is 3/4 ton of course.

The truck has 3 minor issues that I am trying to at least get a handle on before I drive on a 1000 mile trip in a couple of weeks. I just got the truck 3 weeks ago.

1) It tends to diesel for 1-4 seconds when it is hot
2) There is a strong gas smell to the exhaust, and it gets horrid mileage, but it IS a Suburban....
3) It smokes intermittently on startup. I think its valve guide seals, as it is blue smoke not black.

So, what says the forum? I'm going from Reno to San Francisco (and back) in a couple of weeks and am trying to knock out a couple of things before we go.

Thanks a whole bunch I really appreciate any insight you all have.

 

[Texx]

When it's valve guide seals, it smokes like hell when/after idling. No smoke while driviing. If you sit at a restaurant pickup window while rinning, when you take off you'll crop dust the whole building. Dieseling is normall timing or poor fuel. I suggest a good round of seafoam.

 

[jonesy54]

Sea foam is good stuff.
I had an old mazda b series that would diesel when you cut it off. I tried all kind of things. Ended up being the idle setting. I idled it down from about 900rpm to 500-600rpm and the problem went away.
'splain that. Is 300 rpm really that big of a difference?

 

[nspctr1]

Start with the basics, timing etc and then move to the fuel, filter, accellerator cable need adjusting, spring lax, maybe even a compression test....

 

[liljlandon]

Try the fuel filter, then check your tuning on your carb. I have an 86blazer, made the secondarys open up at 2K. WOW talk about 5mpgs and a hell of a ride.

 

[fsusteve]

timing/carb, check one, rebuild the other.