6 MPG?!?! Help Me!!

[hiway]

Eddy carbs have 2 sets of holes. I think all you need is the thin plate and a spreadbore gasket on one side and square on the other. Unplug your vac. advance (cover port on carb) and set you timing to around 10 degrees init. Reconnect vac. If it pings under heavy throttle then back off 2. Shouldn't though. Seems like a q-jet kit plus float will be about $50...and you'll need a gallon can of clean stuff to soak it in which is another $15. And probably need to epoxy the fuel well plugs also. For $125 or so you can trade it in for a rebuilt one. Eddy's and Holley's start at $200 but you'll have to deal with linkage and fuel line issues...esp on the Eddy. I highly recomend another plug change since you've fueled those up pretty good. Keep us posted!

[piecesparts]

It sounds to me that you should quit trying to fix it, The more you do--the worse it gets.

First off a 305 and a 350 should time about the same. SECOND, does this motor have a computer controlled distributor still or has it been changed to an HEI distribtor that has only a couple of wires connected to the cap? The computer controlled u nit will limit what you can do for timing and the HEI will give you many days of happines. The 4 degrees is what the SMOG-COPS wanted in the eighties, and if you have a computer controlled unit, then you should probably not get far from this setting, 6 to 8 degrees advanced is where I would go with the computer units. Since I am using HEI units, I never have timed my V-8s at that low of a setting. Take the time---make sure the vacuum hose is off of the distributor vacuum pot, no matter what distributor you have and then set the timing at 10 degrees BTDC. This will give you a good starting place. I figure as you play with it and adjust will finally end up around 12 to 15 degrees for an initial timing setting. As you adjust the timing, you will feel the motor change in RPMs and the response to cracking open the throttle will be sharper as you move it. When you connect the vacuum hose back to the distributor, keep the timing light on the marks and see if the timing setting moves as you connect the hose. This will tell you if your vacuum advance POT is working or not, because you should expect it to move the timing a little more as you do hook it up. The small things that you are looking for is that with the timing advanced, the motor does NOT "DIESEL" or run on after you shut off the ignition switch and when you accelerate hard, the motor doesn't PING or have signs of "DETONTION" as you step into the gas.

Drive the truck and listen for response and feel the acceleration effects and see if they are better.

As for putting a lower grade gas in and it felt like a better operating motor, I believe that is probably a SNAKE OIL pill for you. Don't get me wrong, but fuel consistency of 87 to 93 Octane will work fine in this motor, and unless you have a very high compression ratio (which would cause excessive pinging on acceleration) the 87 or 91 is all about you would need. If it is a high compression motor, then the 93 Octane may be a better choice. Just maybe you had some water in your gas and the new gas made it less in content.

I take it the 18.8 and the 18.5 numbers are the track times for a 1/4 mile or an 1/8 mile run time. Unless your motor is a true pile of poop, you should do better than that.

[Low84]

Thanks for the info. After reading all the advice you guys gave me and seeing my dad's friend do it with my own eyes. I think I should invest in a timing gun, so I can start fine tuning it.

However, those track times are disheartening. Even though I had a carb on its last leg, the timing set to where it sounded best, and a killer exhaust leak. Those times are still SORRY.

I'm going to start building up my lt1 from now on and hopefully be able to rip a 15 sec time as a baseline #.

The distributor is the stock one, don't know if that helps

I'm going to buy parts that will help the current motor but will also work on the lt1 so for now. I'm looking into purchasing a carb and some electric fans.

[piecesparts]

LT-1 !!!! Are you planning on installing it with the TPI setup or are you going to a carbed intake? Either way, you need to be ready to go for some bucks to install. The wiring harness for a TPI setup is not cheap and the reworking of the factory takes some creative knowledge or a lot of bucks to do. Just thought I would ask, since there is a hint of desire but a need for more knowledge in your writing.

[crawdad]

Originally Posted by Low84

Thanks for the info. After reading all the advice you guys gave me and seeing my dad's friend do it with my own eyes. I think I should invest in a timing gun, so I can start fine tuning it.

However, those track times are disheartening. Even though I had a carb on its last leg, the timing set to where it sounded best, and a killer exhaust leak. Those times are still SORRY.

I'm going to start building up my lt1 from now on and hopefully be able to rip a 15 sec time as a baseline #.

The distributor is the stock one, don't know if that helps

I'm going to buy parts that will help the current motor but will also work on the lt1 so for now. I'm looking into purchasing a carb and some electric fans.

As a college student on a limited budget, it would seem to me that you would need to put your cash where it can do the most good. Forget lt1's and electric fans. Get a good rebuilt carb or have yours rebuilt, put a good tune up on the engine, change the oil and put new filters in it. You should see a marked improvement in driveability and mileage. Also, if you're having this kind of trouble with your truck, why on earth are you running it at the track? I would think you would want to drive it a little more carefully and try to nurse some more miles out of it. If you drive it carefully and take care of it, it just may see you through college. Afterwards, when you're bringing home the big bucks from your therapist job, you can play around at the track and blow that motor sky high if you want to.

[Low84]

Well, I ran it partially because I feel somewhat safe should I blow the engine. I still got the LT1 and ontop of that it seems my friend might give me an 83-84 swb chevy with a good motor/no trans. But really what made me run was adrenaline, I wasn't thinking straight. The other thing was that I spent 50 dollars on gas alone and to just go spectate, I'd rather have a little fun for an extra $5. But your right it wasn't the brightest move I've made.

Now for the LT1 the plans are to run a carb manifold for $258.xx and ofcourse a carb now. If my current motor can hang on for a little while longer the plans are to get the LT1 bored .40 over and get a forged piston rebuild kit for 559.xx. Then swap the engines and put a nitrous cam before I save up to buy the nitrous kit.

Ofcourse I'm just dreaming right now, all I can afford right now is the carb and manifold

Only other option at this point is to buy a Vortec head kit which comes with the heads, head gaskets, head bolts, rocker arms, Edelbrock intake, intake gasket and 12 point intake bolts. For around $750. I would have to pray to god the extra quadrajet I have lying around would work, and even then I would have to buy some headers.

[crawdad]

Originally Posted by Low84

Ofcourse I'm just dreaming right now, all I can afford right now is the carb and manifold

Nothing wrong with dreaming, we all do a little (or a lot) of that, but try to fit your tuition cost into that dream somewhere, eh?

[Low84]

Originally Posted by crawdad

Nothing wrong with dreaming, we all do a little (or a lot) of that, but try to fit your tuition cost into that dream somewhere, eh?

LOL! That's exactly what is making all of this a dream and not a reality. Tuition is pretty high, then I got rent, bills, etc. And I only get about a grand worth of Financial Aid per semester, which doesn't even begin to cover for anything. I'm depending almost entirely on one loan. I just hope all of this pays off.

[hiway]

Get a rebuilt carb and start saving money....your gonna need it.

[piecesparts]

So; you have a couple of motors laying around, one that has another carb on it and you are going through mental hell over the carb that you have on your presntly running truck. Maybe what you should do is move carbs around on a weekend and see if you can gain from that. The trip to the track could easily leave you without a vehicle in more ways than just blowing the motor. That apparently was the least of your worries, try getting another rear end or tranny into that truck on a budget.

[lurch115]

i'd have to agree with everyone else on this one....get a rebuild kit and a new float for the carb. and rebuild it...its cheap and easy to do.... might cost you a little more down there but i know i've done several of them and to rebuild the stock Quadra-Junk (Q-jet) is about $30 for the parts...

second of all...fix the exhaust leak because that could be causing your bad milage too...

and as far as timing on a stock 350...generally they are 8 degrees but you can cheat a little and set it at 6 and see how it runs...generally that will give you a little more kick

[Low84]

Thanks for the info guys. I'm in penny pinching mode right now, so I'm probably going to go ahead and rebuild the quadrajet should the spare one not work.

Is there any special/uncommon tools needed when rebuilding a quadrajet?

I'm probably going to purchase a carb rebuild kit and a "How To" rebuild book. I'm not going back to school 'till mid January so, I got time.


BTW guys, completely off topic but whatever. Does an '80 cab swap into an 84 truck? I know the 73-79 cabs are different (I believe the cab to chassis holes don't line up) but what about the 80 model?

[magnethead]

Originally Posted by Low84

Is it possible that lower octane can have that effect? Or am I trying to make myself feel better?

My truck has a 454 and I run 87 octane. I have no clue where my timing is (i think i have it 2 degrees of where it should be) and I can absolutely kill the throttle pedal without it pinging. I done a 75 ft burnout the other day and the motor didn't even care.

[Low84]

Looks like my luck just changed. My friend who was helping me find a donor truck found one, but decided it was too nice to pass up, so bought it for himself instead. The good thing is he has plans to throw 6.0 and 4l80e in there so he is going to sell me the tbi (centerbolt) engine converted to carburetor to me. So looks like for an extra bucks than I would have spent for just a new Holley 650 carb. I'm going to get a used but working holley carb, serpentine system, headers, engine, and transmission. He also located a rust free (haven't confirmed that yet though) cab for my truck.






Today is a good day!