85 k5 w/305 very sluggish

[patrick687]

I just picked up a nice looking 85 K5 blazer with a 305/700r4 for a nice price. I'm trying to get this thing running well, but it's very sluggish and seems like it has no power. I've changed all the plugs and wires, so that's eliminated. I'm thinking there is something wrong with the carb, and I know nothing about the Q-Jet? carbs (the only carb I've really tinkered with is a Weber DGEV) What kind of carb do I have on my 305? How can I tell if the secondaries are working? Also, when the engine begins to stumble really bad, the choke light will come on faintly. What kind of choke does this carb have? Sorry for all the questions ,but I wanna get this pig runnin' good. Thanks in advance,
Patrick McD

 

[Can Can]

Without a little more accurate description, it's hard to diagnose the problem. When does it occur? What sounds and smells accompany it? How does the truck idle when the engine is cold or hot?

Your truck *should* be equipped with a quadrajet 4 barrel carb. You mentioned that you changed the plugs and wires, but I would recommend changing out the cap and rotor and eliminating the secondary ignition system as the culprit. When you have the cap and rotor off the distributor check that you advance weights aren't gummed up or sticky. A gummy advance can really suck a lot of performance out of your motor.

It's very likely that your problem is fuel or electrical related. Try swapping out the fuel filter and running a can of carb cleaner through the carb. Also make sure that the linkages around the carb are clean.

Also take a close look at all your vacuum lines and make sure that there are no cracks or breaks. A vacuum leak will cause you truck to run poorly(ask me how I know!!! /forums/images/graemlins/wink.gif)

Get back to us with a little bit more info and we'll see if we can give you a little more specific advice.

Oh.......Welcome to CK5!!!! /forums/images/graemlins/thumb.gif /forums/images/graemlins/thumb.gif

 

[patrick687]

Well, I pulled the air cleaner and did several things that seemed to have made a huge difference. First, I tightened up the TV cable, which was really loose. I discovered two open vacuum ports in that maze of hoses under the air cleaner. I plugged both of them, and I ran about a half a can of carb cleaner through the carb. It definitely feels better. As for cleaning the linkage, should I use carb cleaner on that too? Should I put any lubricant on the linkage after cleaning it? Thanks

 

[weisel]

And before anything is messed with on the carb, make sure the timing is correct by verifing with a timing light.

 

[84_Chevy_K10]

[ QUOTE ]
And before anything is messed with on the carb, make sure the timing is correct by verifing with a timing light.

[/ QUOTE ]

Definitely. Couldn't have said it better myself!