I have been a lurker here for quite some time. Now that I finally have my baby, it is time to jump into the conversation. Any help you guys can give would be greatly appreciated…

The basics: '69 convert, originally 350/350, now has a 305 (don’t ask me why.) 4speed.

Bought the car about 2 months ago and it serves as my daily driver. I have been working on continual problems, getting it back to decent running shape. When I first got it, it would stumble and jerk around as though it was dying when I would accelerate while cruising. If I was doing 60 down the highway in 4th and would take my foot off the gas, dropping the RPMs to 16-17 then accelerate back up to the 22-23 range, the car would stumble.

I then installed the following:
MSD distributor cap and rotor
Accel plugs (.35)
MSD helicore 8mm wires
Accel Super Stock coil
New points/condenser (30 deg)
Air, oil, fuel filters

My timing was definitely off and there was no tab installed on the replacement engine so I could set it. The stumble was gone, but I was starting to lose acceleration, the car would knock a little, and sometimes backfire through the carb. When I was doing the work with the distributor, I realized I could turn it by hand, so it was progressively going more out of time. Tried to set it by ear, but that didn’t work out so well. Took it to a shop, had them turn it to TDC, install a timing tab, and set the timing. They put it at about 12 deg advance since it seemed happiest there.

That made it happier, but I had zero acceleration. The car then started to run very rough when it was hot, didn’t want to start, tailpipe backfires, etc. When looking at the inline fuel filter, I could see some sputters of gas or none at all. So, I replaced the fuel pump with the standard 3 line mechanical one and replaced the rubber lines. Now the fuel filter is always full.

The car idles and runs very smoothly, doesn’t vibrate excessively, but still, zero acceleration. I get beat off the line by fully loaded minivans. At times, it is even a safety hazard because I accelerate so slowly. The lack of acceleration is at its worst if I hit the pedal hard. The RPMs jump up, but the car goes nowhere. It is a little better if I come off the clutch very slowly almost bogging down the engine.

When I had the car in the shop for the timing work, the mechanic pointed out a few things on my carb...

(It is a Q-jet, by the way. I would guess it is the original, though I don’t know that for sure.)

1) when you spray water at the base, the car dies
2) when you put your hand over the top of the carb, the RPMs go way up
3) when you hit the throttle, the big butterfly valves don’t move

They also pointed out that the pressure in my #1 cylinder (which they tested when finding TDC) was only about 80psi.

The carb looks like it has never been touched; however, I really don’t know the history of the car. I plan to take the car in tomorrow to have the carb rebuilt at Pinellas Carb here in Tampa. Would you guess this is the problem? Obviously, the compression is a little low and the carb needs work, but do you expect the carb is the source of the terrible acceleration problem? Worth the $300 to have them rebuild it, install it, and tune the car with their emissions tester? I plan to put a 350 in it at some point, but I would like to have some fun with it as a daily driver till I can afford that move, but the car is almost undriveable now. Besides, where is the fun in driving a beautiful ’69 if it doesn’t act like one?

 

I'd hold on before heading into the carb shop. There is a gentleman here on the forum named Lars who is the Quadrajet guru. He may be able to help you either by rebuilding your carb, or by helping you through it.
He does have some FAQ papers, and I can email the Q-jet ones to you if you send me your email (PM would be preferable). There are a lot of people here on the forum who have spent big bucks trying to get their Q-jets running right (me included), only to have Lars look at if for about 30 minutes and fix it in a jiffy.

Good luck,

trw

 

I actually got the papers from Lars yesterday and sent him the link to this thread to get his input. Thanks for the quick reply!

 

It sounds like almost all the system in the carburetor are very lean. If this car is a daily driver you may want to get a reman carburetor to cut down time. I have heard good things about the Jet Performance Quadrajets. You can find them here.

http://www.jegs.com/webapp/wcs/store...0271&langId=-1

Look at #561-35002.

BigBlockk

Later.....

 

On top of what might be carb and ignition advance problems, you say when you hit the gas hard the rpms jump up but the car goes nowhere. Your clutch must be slipping badly. Must need adjustment or replacement. Good luck.

 

On top what has been mentioned you might need a BB

 

sound like you ve got some gasket problems, possible a power piston spring, and maybe even some low compression.


I would runs a compressiontest acrosss all the cylenders, replace the carb to intake gasket, I would rebuilg the q jet and check to see if teh air horn is warped, which could cause the probles you describe. Next get a vacuum gage and check the vacuam at the intake, and look for eitehr low reading or a jumping needle readign to indicate problems... a tructy chilton will help you here withthte diagnosis. from there well it depends on what you find but you get a good ideal of wjhat is going on in your engine.


the best thing though would be to ditch that 305 and find yourself a 350 to swap in



good luck and welcome'



tim

 

So, I took the car by they carb place this morning only to find out there was some confusion about my reservation. So, the work has been postponed till Tuesday. I am so anxious to get it done that I am somewhat kicking around the idea of ordering the replacement as per BigBlockk's suggestion. However, I guess I can suffer through a few more days of sluggish driving to have someone set it up correctly for me.

BKbroiler, that is a good point that I hope is not the case. The clutch seemed to be working fine before the acceleration problem developed, so I am hoping all is well on that front. Otherwise, I will add it to the never-ending list...

Vesa, while I agree that would be more fun, I plan to drive this car everyday for the foreseable future and I dont think the BB fun would outweigh the fuel costs. Besides a fairly original 350 would be enough power for me.

Tim, I agree with your analysis and you obviously know more about these things than I. My understanding of carbs ends at the fuel filter (air horn? power piston? I need to read up on carbs.) Now that I have the ignition system working well, the fuel system is next on the list. Hopefully this carb rebuild will bring everything up to par on that front. After that, I can start worrying about the compression issues. If it needs new head gaskets, I may do that, but if it needs new rings/pistons, I will probably just wait and save up for that 350.

Thanks for your input, everyone. It is nice to see that you guys are so willing to help the newbie. I will update this when I get the car back from the shop which will likely be on Wednesday (2/8).

 

No problem, definely go and get some literature on the subject.

There a several good books on the rochester carburator, as well a perfomace tuning your small block chevy, right in the automotive section of your local barnes and noble. these will give you a great deal of insight, also pick up the Classic Chiltons repair manual or shop manual for your car. Lost of basic tuning procedures and diagnostic information too



good luck and cheers



tim

 

1) when you spray water at the base, the car dies
2) when you put your hand over the top of the carb, the RPMs go way up
3) when you hit the throttle, the big butterfly valves don’t move

You have a vacuum leak 1) & 2). Probably at the carb base. You spray water, it gets sucked into engine. Hand over top of carb chokes off air. If rpms go up, you have an vacuum leak.

Secondary air valve (not throttle valves) will not open coming off idle in neutral. Gotta have a load.

 

So, this weekend I went out and bought a replacement carb-to-intake gasket and threw it on there. I took a picture of the old one, but I have not figured out how to put it up. Basically, the old one was about a quarter of an inch thick and very brittle. It also had a very thin sheet of metal underneath it. I cleaned the metal piece and put it back on under the new Mr. Gasket gasket.

Additionally, at the suggestion of Lars, I double checked my timing and found that I was a little too advanced.

The car runs amazingly smooth now. I can start it without pumping the gas and it immediately idles. It is quieter, idles lower, and doesnt seem to be working as hard. Even the exhaust seems less forceful.

HOWEVER, the car still does not move. I have become fairly convinced it is, as BKBroiler suggested, a clutch problem. I can completely dump the clutch and not go anywhere. When the engine revs too high for the clutch to catch up, the car hardly moves and I smell a strange burning that I dont recognize. Seems like it is time for a replacement. Now, considering that I am a clutch moron (much like my carb understanding), I will probably start another thread looking for suggestions. Thanks for the help, everyone.

 

Yep, sounds like the clutch is toast. Get out the jack stands and floor jack. Its heavy so be carefull.
Got a book yet?
You can do it, save a buncha bucks and be able to say "I did that"

 

I would love nothing more than to be able to say that, but this is my only car. Knowing that I have to get it done in a day and that I will likely mess something up, I cant really risk doing it myself.

Still no decent book. I have a Chiltons from that era, but it is kinda a general "all cars" version that is not very detailed (found it in my dad's garage.) So, yeah, that is definitely on the list...

I am about to post a new thread titled "clutches 101" and would appreciate your input.

 

It can be done in a good evenings work, few hours.
Put the car up on jack stands
disconnect speedo cable, shift linkage, clutch linkage, drive shaft
remove crossmember (I think)
4 bolts hold tranny to bellhousing
slide tranny out (its heavy, get help if you can)
remove bell housing bolts, put it aside
Remove pressure plate bolts, pressure plate and clutch disk

reverse order it goes back in

It sounds simple and it is really, but there is a lot of stuff to look at and would be better with some experience with you.

Check the auto parts stores close by, you might get lucky and they have a chiltons or haynes book. Barns & Knoble, etc

you will need to look at the T/O bearing and ot clutch is badly burned maybe flywheel too

Or, just let a good local shop do it.
Where are you? what part of the country?

 

I'm in Tampa, FL. Just got a quote from a nearby shop for $485

 

Is that complete or just Labor?
an ok deal if labor, good deal if including parts

 

thats for the whole thing (+ tax, of course). failed to ask if that included the flywheel resurface. got another quote yesterday and he said it would be about $300 for labor + $30 or so for the resurface and then i can just go and get the clutch i want. advance auto has the stock replacement for about $120. so, $450 + tax is not as painful as i thought the project was going to be.

 

The price seems about right for the job, just make sure its a reputable shop, and get to know the guy actually doing the work. when you get the car back check out the pedal movement, and "feel" aslo make sure you getting back all the stuff you brought there, hate to say it but bad things happen to good people all the time. also vist the shop and ask to see the tranny while its out, and this is a good time to take a close look at the undercarriage. Even for the beginner, this can be an educational experiance. The more interest you show, the more likely youll be satified withthe job!!!


Good luck



tim

 

Sounds like you did ok, let us know how it comes out

 

Just a quick thought

make sure a new throw out bearing ins included in the price as well as find out if it includes a new pilot bearing. and since the muncie is out, its a good idea to drain and change the gear oil too. I know it may be a little extra, but if this is your daily driver, then it is best to have it done and not have to worry about it. Lastly while its up on the lift anyway, also drain and changeing the gear oil in the rear differential is a good idea as who knows when it was last done. (PS dont forget the posi addative!!!)



Tim