First GM Car! 1969 Buick Skylark Convertible

[1969 SkylarkCustom]

Hello All!

I've been a Ford guy my whole life (boo...boo...) but I decided to branch out a little and try a new brand. I picked up a 1969 Buick Skylark Custom Convertible last week and I'd like to learn a little more about it. Mine is equipped with a 350 engine, but it has a 4 barrel carb on it, and all the documentation I can find on these cars suggests the 350's only came with a 2 barrel. How can I tell if its originally a 4 barrel motor? or if someone just swapped intakes? Also! TH350 trans! is it the first year? I know it has 3 speeds because it shifts twice and the column shift calls out L2 and L1. I am excited to learn more about this car and enjoy it!

Ben

[bob k. mando]

suggests the 350's only came with a 2 barrel.


certainly not true.

https://www.teambuick.com/reference/...ine_number.php

if yours was originally a 4 barrel car the engine will have an "RP" stamping and the last six digits of the EIN will match the VIN.

one thing, if you have any issues with pinging it's due to the higher static compression of the performance engine designed for leaded fuel. you'll either need to run premium or a 100LowLead AvGas mix.

AvGas will be available from most local airstrips and, if you shop around, can be much cheaper than race fuels, down near the price of premium. try AirNav.com, my cheapest current price is $3.66


we have both the 1967 and 71 chassis manuals, so you should be able to cover most of your cars systems. the 71 will be most applicable ( the 67 has the earlier 340ci which has certain minor differences ) but the 71 will have some emissions controls on it that yours will not.

https://www.teambuick.com/reference/index.php


that year Skylark / GS could also come with a 400ci engine which, externally, is the same as a Buick 455. this ( the 455 ) is a common upgrade that people like to throw in. there are some mods necessary but it's pretty straightforward.

the Buick 350ci ( NOT the same as a Chevy 350ci ) is a respectable performer in it's own right and VERY light for the displacement ( ~470lbs ), but it's always been the red headed step child of GM so there isn't much in the way of cheap aftermarket parts for it.

www.TAPerformance.com is the primary Buick vendor.



yes, 69 is the first year for the TH-350. you can have even more gears if you throw in a 200r4.

[1969 SkylarkCustom]

I found the RP between cylinders 1-3 under 2 inches of dirt and grime... but its there, so thats a score, factory high compression and 4V engine. sweet! now my next question is, why does it like to diesel after i shut it off? only after running it nice and hot, then when i shut it down it diesels for 30 seconds or so and then dies.

is this carbon buildup on the tops of pistons? or too rich idle condition? plugs look really good, like not super rich.

could it be a timing issue? and what do you recommend i do to fix it?

Ben

[bob k. mando]

gasoline engines ( should ) cut spark when you turn the ignition off, so if it's continuing to diesel something is definitely going on.

wouldn't surprise me if the carb is leaking fuel.

remember, this is a 55 year old car and a lot of the rubber and cork and plastic is going to be in BAD shape. so if you do a carb rebuild, get a full set of everything. also, the Quadrajet is VERY easy to overtorque. if you use too much torque you'll warp the carb and create vacuum leaks. get an inch/pound wrench and use it.

the 71 chassis manual is here:
https://www.teambuick.com/reference/...ssis/index.php


here's the site owner's ( different Bob ) article on timing;
https://www.teambuick.com/reference/engine_timing.php