Engine Cutting Out - Impala Tech
Troubleshooting Diagnosing problems

 
LinkBack Thread Tools
post #1 of 7 (permalink) Old 12-11-2010, 06:41 PM Thread Starter
Member
 
Join Date: Sep 2009
Location: Kansas City, KS
Posts: 40
 
Engine Cutting Out

So this isn't really an Impala specific question, more of a I'm an idiot/general automotive question.

My Biscayne lacks power in the upper rpm band, in fact once you get above 3 grand it barely accelerates even with the throttle pressed all the way down. So I decided my car isn't getting enough fuel and my carb is probably dirty. I got a couple big cans of carb cleaner and sprayed a bunch down in there earlier today while the car was running.

Well when I went for a test drive instead of getting all this extra power I was expecting my car runs much much worse. It starts and idles just fine but once you give it gas it sputters and barely runs. It will get you down the road without dying, but it feels like I'm driving a riding lawnmower.

So help me out here...I'm wondering if I didn't get overzealous and put too much carb cleaner in and it hasn't evaporated yet, or if my car is just running super rich now? If it were too much carb cleaner I don't see why the car would even start and idle fine, but I thought I would ask anyway.

The other thing that makes me think running rich is that I changed out my fuel filter a little while back and I think it made the cutting out worse. Could be my butt dyno playing tricks on me, but I would swear the car had just a little less power after changing the filter.

By the way the car is a 350/powerglide/quadrajet so no adjustment screws for me either.
dmac is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 12-12-2010, 09:44 AM
Moderator
 
Join Date: Jan 2006
Posts: 12,372
 
Problem with your old motor is that it is old. When you ran the carb cleaner through the engine it removed not only the varnish and gum in the carb but the build up of lead and carbon inside the combustion chamber and on top of your pistons so you are now down even more on compression. (by removing the built up lead you also removed the lubrication your valves needed to survive in an unleaded world as your valve seats are not hardened the way they are on new heads).

I would take it to a competent OLD mechanic who knows what points are and how to tune a carburetor (few people working in the trade today do as EFI and HEI have been around since 1975). It may be time to tnink about a new crate motor to replace what you have with more cubes.

Big Dave
Big Dave is online now  
post #3 of 7 (permalink) Old 12-12-2010, 09:59 AM Thread Starter
Member
 
Join Date: Sep 2009
Location: Kansas City, KS
Posts: 40
 
Well I'd love to replace my engine with a crate motor but funds do not allow at the moment.

The 350 isn't the original engine and was swaped in by a previous owner and I thought it was good to go on unleaded gas. The head castings are old but the engine was built post at least post-1980 (and probably more recently than that) because it has an 80 Corvette aluminum intake on it, so I would think it has hardened seats.
dmac is offline  
 
post #4 of 7 (permalink) Old 12-12-2010, 10:05 AM
Senior Member
 
Join Date: Oct 2009
Location: Orange, CA
Posts: 1,329
Blog Entries: 34
 
I would suggest a carb rebuild. As Big Dave said, the carb cleaner loosened up a lot of old gunk, some of which probably got redeposited or stuck into some vital small passage.



100% free webcam site! | Awesome chicks and it is absolutely free! | Watch free live sex cam - easy as 1-2-3

1964 Impala 4 door sedan

My Bloggy Thing: http://www.impalas.net/forums/blog.php?u=2285
dcairns is offline  
post #5 of 7 (permalink) Old 12-12-2010, 12:08 PM
Senior Member
 
Join Date: Nov 2010
Location: West Jefferson, Ohio
Posts: 270
 
I also would suggest a carb rebuild, as well as installing an HEI distributor if you don't have one already.
AK99 is offline  
post #6 of 7 (permalink) Old 12-12-2010, 01:12 PM Thread Starter
Member
 
Join Date: Sep 2009
Location: Kansas City, KS
Posts: 40
 
Alright, thanks for the advice everyone. I may just pick up a new Holley instead of rebuilding this one so I can have some adjustability. I know the quadrajet is a good carb, but I'm an amature mechanic and rebuilding it right is probably out of me league anyway.
dmac is offline  
post #7 of 7 (permalink) Old 12-12-2010, 05:52 PM
Moderator
 
Join Date: Jan 2006
Posts: 12,372
 
Whatever you do, don't trash the Rochester QuadraJet; those carbs are getting harder to find every day (I am gulity of circular filing more than a few when yonger so I have to atone for my sins).

They can be rebuilt with a book explaining how to do it (a simple instruction sheet won't cut it for first time rebuilders), and a few parts and they go together in the exact oposite way that they came apart: just like most carbs. However the external linkagage and hair pins to hold everything together is intimidating to many people. Adjustment isn't as intuitive as it is on a Holley either but it is a fine carb once set up for your engine (properly tuned).

The days of finding a rebuildable 600 cfm 4160 Holley for $25 is about over also, as they were asking over a hundred for many cores (though most were the more desireable 4150 models) at the swap meet last time I was there.

Big Dave
Big Dave is online now  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Impala Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome