Hi Friends,
I have a problem with my 87 K5 blazer (350 V8 with 4 Bar. Carb and electric fuel pump). I have to run it for a couple of minutes every 2 days or else it will give me hard times in day 4!
Last time i didn't start it for a week, i had to put some fuel in the Carb to get it started. I'm sure that the pump runs as soon as i turn the key (i can hear it running), Any ideas??
is this normal for a 23years old car?
how can i fix it?

 

Sounds like the well plugs in the carb are leaking. I had to seal up the ones in the Q-jet on my K5 due to the same scenario. In my case, the secondary metering rod wells were still sealed just fine, but the primary metering rod wells were leaking. I used a bottoming tap to put threads into the bosses and then made some shallow plugs out of few bolts, cutting slots to then be able to thread them into the now threaded holes. I used some JB Weld on the threads to keep them sealed in place.

You should be able to find a lot of information about this issue from google using "quadrajet+well+plugs" as a search term.

*Moving to Fullsize K5 Tech* - The 1st gen area is for the s-series trucks.

 

Thanks, actually i had my Carb fixed few days ago and the guy removed the seal (it was alreday there! but i had the same problem, but maybe coz it looked very old and torn in some places) i guess i'll have to apply a new one.
do u think i can do it myself? or it will needs retuning afterwards? i'm not afraid to do it, unless it need pro tuning

 

If you are talking about the little piece of felt that is below the primary metering rod well plugs, then that isn't the seal. The plugs are the seal, or rather, they were intended to be, but as the carb ages, the factory lead plugs do not seal as well as they originally were intended to and need to be replaced.

You really need to tear the whole carb down to properly repair the well plugs. This is primarily due to the need to clean all of the ports after repairs have been made.

 

Dude, you run a Quad-J in your truck???? Do you like it??

 

Yes and yes. I have been messing around with Q-jets for over 20 years. If in proper working order, they are a great carb for performance and efficiency.

 

Performance and Efficiency...with the same tune at the same time? When I got my K5 it had one on it along with a smog pump, EGR and the like.....the float was stuck (pouring gas out of the top) I rebuilt it, and it worked. but never really loved it. I got the Edelbrock that I have now and it's ok. I done have issues with losing power up hills and around corners so I just run it. I'm sure I can do better, but I go with basic drivability on mine. I knew when I bought it that it wouldn't be the specimen on the stage at Barrett Jackson in 30 years. I didnt restore it to factory specs Im just getting it to be functional.

 

Setting up a Q-jet properly takes experience. They are much more difficult to get setup properly, but once setup, they work and work quite well in my experience. My biggest problem with the one on my K5 is that the float bowls overflow when I have the nose in the air and flood the engine. But not many carbs can take a 30+ degree incline. That's why I will be swapping in a TBI motor when I get around to it. I already have the motor and everything to make it work for less than the cost of a Holley Truck Avenger carb or equivalent.

 

I mean that there was already epoxy seal, but it looked old and beaten, so the guy took it off the sec Well seals and didn't put new one.
so, if i followed the insturction of how to remove the carb and dismantle the base, then apply the epoxy and let it dry for a whoel night then i put it back on, will i need to retune it? or as long as i didn't mess up with the "tuning screws" it will be the same as before? or i still need a pro?

sorry if i'm asking a lot of question or i'm repeating it, but u have no idea how hard it is here in Egypt to get ur old chevy fixed! or even to get a part that fits )))

 

I don't like the 'coat it with epoxy' method of sealing the well plugs. I have always repaired them using bolts, threading the bosses or with new plugs; in both cases, I coated the connection points with epoxy prior to installation. Just putting epoxy over the current plugs doesn't seal up where its leaking, just further out and many epoxies will swell/soften over time when exposed to heat and fuel.