The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 03-04-2018, 11:34 AM   #1
luke1968c10
Registered User
 
luke1968c10's Avatar
 
Join Date: Oct 2013
Location: hindman ky
Posts: 40
68 chevy losing power mid throttle

I have a 68 c10 with 250 straight six 3 speed on the column.
It idles great and is smooth. When moving around just over idle it runs good. After about 1/4 throttle it loses power and refuses to accelerate until the throttle gets all the way to the floor. After it's on the floor, it runs great. I replaced the carburetor with a new one and it's still the same. I have upgraded the ignition to the HEI distributor. Plugs are not very old.
Any advice would be greatly appreciated. Thanks.
luke1968c10 is offline   Reply With Quote
Old 03-04-2018, 12:25 PM   #2
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,707
Re: 68 chevy losing power mid throttle

What’s your initial timing?
geezer#99 is offline   Reply With Quote
Old 03-04-2018, 12:38 PM   #3
luke1968c10
Registered User
 
luke1968c10's Avatar
 
Join Date: Oct 2013
Location: hindman ky
Posts: 40
Re: 68 chevy losing power mid throttle

I'll have to check it. It was set at around 4 degrees tdc. My timing light broke so I'll have to pick up another one.
luke1968c10 is offline   Reply With Quote
Old 03-04-2018, 01:43 PM   #4
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,707
Re: 68 chevy losing power mid throttle

Plug off the vac advance to set your initial at 14 degrees.
4 initial is not near enough.
geezer#99 is offline   Reply With Quote
Old 03-04-2018, 02:38 PM   #5
luke1968c10
Registered User
 
luke1968c10's Avatar
 
Join Date: Oct 2013
Location: hindman ky
Posts: 40
Re: 68 chevy losing power mid throttle

Lol. I had to check my last post. I guess I didn't press the 1 very good. I meant 14. It's probably moved or something since then. I'll see if I can borrow a light somewhere. Thanks, for the info, for some reason I didn't think about the timing.
luke1968c10 is offline   Reply With Quote
Old 03-04-2018, 03:08 PM   #6
mike16
Registered User
 
Join Date: Dec 2009
Location: bisbee, arizona
Posts: 1,529
Re: 68 chevy losing power mid throttle

no fuel contamination, like from rust or dirt. did you ever pull your sender/pick-up?
mike16 is offline   Reply With Quote
Old 03-04-2018, 03:51 PM   #7
luke1968c10
Registered User
 
luke1968c10's Avatar
 
Join Date: Oct 2013
Location: hindman ky
Posts: 40
Re: 68 chevy losing power mid throttle

Haven't checked the fuel pickup yet. I replaced the filter and it wasn't clogged up or anything. I'll pull that out and check. Thanks.
luke1968c10 is offline   Reply With Quote
Old 03-06-2018, 08:01 AM   #8
luke1968c10
Registered User
 
luke1968c10's Avatar
 
Join Date: Oct 2013
Location: hindman ky
Posts: 40
Re: 68 chevy losing power mid throttle

Hey guys, thanks for all the help. It turns out the new fuel filter I put on was defective and was restricting the flow of fuel. I took it off and tried to blow through it, just barely anything coming through either way. Put another filter on and she perked right up! Doesn't make a whole lot of sense because the other filter I replaced wasn't clogged up. Oh well, at least she's running good again.
luke1968c10 is offline   Reply With Quote
Old 03-06-2018, 08:47 AM   #9
Barnfind46
Registered User
 
Barnfind46's Avatar
 
Join Date: Aug 2014
Location: Mena,Arkansas
Posts: 485
Re: 68 chevy losing power mid throttle

I have had some issues with my carb and fuel contamination. I finally got it running really good and it started to stumble on the highway yesterday.Come to find out my fuel filter was getting stopped up. Anything over an idle was too much for it. Changed it and I'm rippin down the road. Not exactly your problem but similar. At least yours was simple!
__________________
68' with no bells or whistles unless I add'em.
Barnfind46 is offline   Reply With Quote
Old 03-06-2018, 01:43 PM   #10
toolboxchev
Registered User
 
Join Date: Jul 2015
Location: 2nd left past the stump on a dirt road.
Posts: 2,629
Re: 68 chevy losing power mid throttle

Quote:
Originally Posted by luke1968c10 View Post
Hey guys, thanks for all the help. It turns out the new fuel filter I put on was defective and was restricting the flow of fuel. I took it off and tried to blow through it, just barely anything coming through either way. Put another filter on and she perked right up! Doesn't make a whole lot of sense because the other filter I replaced wasn't clogged up. Oh well, at least she's running good again.
Glad to hear it. I have had similar problems with other systems and replaced a part not related and the dang thing just started working again.

Sometimes it's Casper the Friendly Ghost just coming around letting you know your not forgotten!
toolboxchev is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -4. The time now is 07:49 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com