1966 chevy truck help.

[joe1966]

I have a 66 chevy c10 2wd 4 speed. with 350 small block with hei disrib and AC delco plugs and streetfire or msd wires pretty much. When i go to start it up sometimes it will run bad like kinna really choppy sounding like the plugs are dirty, i will kill it then go under the hood and take off each plug wire one by one then go and try it again and it will run really smooth, what is wrong! its doing it more and more each day. the plugs are probably a week old and the wires are probably a month old or less. thanks! joe

[Captainfab]

Is your timing set correctly? Is the carb adjusted? What carb do you have? It sounds to me like it is loading up.....a carb/ fuel problem.

[joe1966]

Quadrajet 4 barrell. How do I get the fuel problem fixed? Like a adjustment ordeal? Its pretty old but I just rebuilt it recently
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[61K10]

you said streetfire--do you have splitfire plugs? if you do get rid of them. ck carb float and needle/seat. could be leaking while sitting.

[SIR]

How big is your carburetor? 500-650 should be just right...750+ too much...

[tincan1966]

if just talking the plug wires off at the plugs and putting them back on fixes the problem , I would lean towards a possible connection problem between the plugs and wires. Try putting some dielectric(sp?) grease around the plug boot when installing them and see if that helps. Could be as simple as a little condensation buildup.
Also, I'd check and make sure you have a good ground between the engine and the frame or battery.

[BillWallace]

I also suspect a carb tuning issue. Does your q-jet have an electric choke? If you are leaving the key on while playing under the hood you may be giving it enough time to open up the choke.

[Captainfab]

Do you have experience with rebuilding a Q-jet? Are the floats set correctly? What about the choke as mentioned above? Did you epoxy over the plugs in the bottom of the fuel bowl?

[61_FL_Apache]

Have you pulled your plugs out and look at them to see how its running? What color are they? That will tell you a lot too.

[GMR-PERFORMANCE]

Well if the problem can be corrected even for the short time be taking wires off, why would the carb effect that? Nothing has changed in that area. Moisture in cap? poor ground on the module? cheap cap and rotor maybe slight arcing going on? I have always been a fan of OEM delco ign parts. Clean the module base and apply dieelectric grease under it. Good cap and rotor, clean connections every where. Start with the easy stuff before jumping around and spending time and money on items that may not have anything to do with it.

If it comes down to the carb, Drop me a PM I have a great book I can send you on rebuilding the Q Jet carb. Some guys dont like them and state they are junk carbs. I think that many get a bad rap as the people working on them have no clue on how to correctly repair and tune them.. Most have no idea how to correct the bog they get when the secondarys open up. Screw is on right side under linkage, add 1/2 turn to increase pre load and you will find that most of the time it will stop the bog.

But that is off topic at this point. Start with what you know corrects the issue and look deeper into that area. That would be how I would do it.

One orther thing are you still running a EGR valve?? If so take a vaccum reading as well..

[ctandc]

Originally Posted by GMR-PERFORMANCE

If it comes down to the carb, Drop me a PM I have a great book I can send you on rebuilding the Q Jet carb. Some guys dont like them and state they are junk carbs. I think that many get a bad rap as the people working on them have no clue on how to correctly repair and tune them.. Most have no idea how to correct the bog they get when the secondarys open up. Screw is on right side under linkage, add 1/2 turn to increase pre load and you will find that most of the time it will stop the bog.

Amen. I used to love the looks on guy’s faces when the secondaries on my 67 SS Chevelle (396/QJet, then 454/ QJet) opened up. NO OTHER SOUND LIKE IT IN THE WORLD!!! LOL.

Old guy who taught me about Q-Jets always said

“90 percent of carb problems ain’t.”

LOL

[Rich 5150 69]

Originally Posted by Captainfab

Do you have experience with rebuilding a Q-jet? Are the floats set correctly? What about the choke as mentioned above? Did you epoxy over the plugs in the bottom of the fuel bowl?

I had that problem with one quad...had thought for a while it was floats, leaking plugs are a pain...

[joe1966]

Ok. so it hasnt been giving me any probs lately, i have a choke on it but its not hooked up. i took one of the little pieces of steel out of it. but it can easily be put back on. when i go start it i have to pump it and when it starts i have to keep it kinda around 1500-2000 rpms. until it warms up. i just put a new cap,rotor and module in it with dialetric grease on the module. and just recently had my uncle, professional mechanic help me time it back to were it needed to be. secondaries open up very nice. sounds amazing! my favorite part is the secondaries. any ways. i just put brand new streetfire spark plug wires with brand new ac delco plugs gapped at .45. I have not put dialetric grease on them but will do when i get home. thanks ya'll

[bonacker]

You don't say when the distributor was converted to HEI (bought it that way or you did the swap) but one thing to remember is the HEI must have full +12 volts to operate correctly. If I remember right, the factory distributor wire is a resistance wire and drops the voltage to around 9 volts (I think). I had to run a new wire from the fuse block directly to the +12 terminal on the HEI, using an ignition switched fuse on an El Camino I built years ago. Hope this helps.

[joe1966]

Yea i ran the 12 guage wire from the ignition unfused terminal to the hei distributor. now i have no problems. everything is great now