Starting problems..... where do I start

[hinkv10]

I haven't been on in a while... life... and haven't been driving my K10 much

Technically she is an 87 but the engine is from a 84 and is carbed, 305. Four years ago I installed a Quadrajet from Shaun Murphy Induction on a Recc from here. It has been perfect until last week. It would start in sub zero temps but started (pun intended) giving me trouble about a month ago.

I thought it might be fuel related as I don;t drive it much but 2 tanks of fuel and it is doing the same thing.


It cranks but will not start, does not really even try... I think it is carb related as I sometimes can get it started but I had to twist the electic choke towards the center mark to get it to start but now it has developed a bog upon takeoff.

Yesterday I moved the choke back to the farthest mark counter clockwise and it won't start for the last 2 days. I smell fuel and I will say that when it started 2 days ago I cranked it for 10 seconds and then pumped the gas 3x and after some cranking it will start. Restarts are not a problem and i took it out in the storm sat night and had a little fun. Even after hitting the grocery store and it cooled a bit, it started right up..

I'm thinking it may be flooding but have zero experience with Quadrajets. Where should I start? I've cleaned the jets in my Edelbrock which you can do with it in the truck.

Thank you in advance for any advice

 

[austinado16]

Firstly, make sure you have the correct weight of engine oil, for your start temps. Oil that is the wrong weight (too thick when cold) can cause cold start issues because the cranking speed is simply too slow to light fuel. Similarly, makes sure your spark plug gaps aren't too wide. Wider gaps are much harder to fire on cold starts, and that's magnified in severe cold.

Once you have those 2 things handled, remove the air cleaner and check your choke function, in order to make certain that the choke is fully closing for cold start. If it's not fully closing, adjust it CORRECTLY, and try to re-start the engine.

Engines take spark, fuel, and air in order to run. You know it runs, so you have all 3. That should lead you to first 2 things I mentioned, and then to the choke function.

 

[1987 GMC Jimmy]

I've often found that carburetor problems are rarely carburetor problems at all. Not saying yours isn't. Are you getting two squirts of fuel when you actuate the throttle? How many turns out from lean are your curb idle screws? You may need to adjust. If you haven't invested in a carburetor adjustment tool, I would. O'Reilly's has them on the shelf usually. I'd also check to make sure you're getting a nice, bright bluish whitish spark so you can rule your ignition system out. I'd just start by making sure you're getting two good squirts of fuel down the carb and pulling the plugs to make sure they're not soaked. While you do that, you can ground a plug and check your spark quality. I agree that you're getting fuel, spark, and air, but I would check to make sure you're getting them properly in addition to the aforementioned. Just my $0.02.

 

[hinkv10]

Thank you for the advice and brain storming.

Oil is 5w30. the electric choke seems to be working as I checked for power and observed the butterflies on top of the carb move as it warmed up.

I'm thinking the plugs might be gunked up... I have to replace the header gasket anyways (only been 2 years) so I'll either replace or clean and adjust the plugs.

thanks for the advice

 

[BiggG74]

I had a 327 in my impala that did a similar thing. It ended up being the coil had started going bad. It would work and then quit. Changed it and it fires up.


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[austinado16]

Thank you for the advice and brain storming.

Oil is 5w30. the electric choke seems to be working as I checked for power and observed the butterflies on top of the carb move as it warmed up.

I'm thinking the plugs might be gunked up... I have to replace the header gasket anyways (only been 2 years) so I'll either replace or clean and adjust the plugs.

thanks for the advice

Is 5w-30 the correct viscosity for starting in your coldest temps?

Don't waste your time cleaning spark plugs. Just purchase a quality brand set, make sure they're gapped correctly, and install them.

 

[hinkv10]

I think she's fixed!!!

It was 30 degrees this afternoon and I was able to get her started. I cranked her for 10 seconds and then hooked up the electric choke and turned it to its furthest position counter clockwise. took a couple cranks and I kept it running for a solid 30 minutes as I ran errands. I had put a full can of Marvels Mystery Oil in the tank and filled it with gas and it seemed to help a bit.

After I put the plugs in, she roars to life! I had NGK's in there that were only 4 years old with maybe 10k on them. Number 3 plug had some oil leaking from the valve cover so maybe it was causing it to foul, I'll keep an eye on that plug. AC Delco R45TS, I'm sure they will do better than the *** plugs.

Easy fix and thanks for the advice