Ford Truck Enthusiasts Forums
Older, Classic & Antique Trucks
1973 - 1979 F-100 & Larger F-Series Trucks
...strange problem.

1973 - 1979 F-100 & Larger F-Series Trucks Discuss the Dentsides Ford Truck

Sponsored by:

...strange problem.

Reply Subscribe

Search this Thread

Old

Aug 9, 2012 | 11:20 PM

#1

PatientZero

Thread Starter

|

Freshman User

Joined: Jun 2012

Posts: 39

Likes: 0

...strange problem.

Okay. I'm working on my 1978 f100 with a 300. Auto transmission and original Carter yf. Carb. Truck runs like a dream in park or neutral, but as soon as put into gear, it idles way too low and backfires through the Carb when given gas. I've replaced plugs, wires, coil. Rebuilt carb and changed manifold gaskets. Adjusting timing doesn't seem to be helping any. Does anybody have any ideas about what i may be missing?
-patientzero

Reply

Old

Aug 9, 2012 | 11:24 PM

#2

devino246

Post Fiend

Joined: Mar 2011

Posts: 8,501

Likes: 4

From: Lynchburg, VA

Start checking all your vacuum lines. Sounds like a vacuum leak.

Reply

Old

Aug 10, 2012 | 07:13 AM

#3

fmc400

MSEE

Joined: Apr 2004

Posts: 10,386

Likes: 35

From: Austin, TX

Club FTE Gold Member

Agreed, sounds like a vacuum leak. I'm also going to assume that when you adusted the timing, you used a light and NOT by ear.

Reply

Old

Aug 10, 2012 | 10:46 AM

#4

Rusty_Old_F250

Fleet Mechanic

Joined: Aug 2009

Posts: 1,771

Likes: 9

From: Western Washington

Check your booster, get a pair of vice grips and use them to clamp them onto the vacuum line for the booster then test drive it.

Sam

Reply

Reply Subscribe

Related Topics

Thread

Thread Starter

Forum

Replies

Last Post

239 flathead v8 timing issues

cosmaar1

1948 - 1956 F1, F100 & Larger F-Series Trucks

18

Sep 11, 2016 08:39 AM

1978 351 runs like crap!

RShaips

1973 - 1979 F-100 & Larger F-Series Trucks

16

Dec 15, 2014 03:40 PM

Chasing a Vacuum Leak

VocaTexas

1973 - 1979 F-100 & Larger F-Series Trucks

6

Jan 26, 2014 12:55 PM

My Cleveland is driving me mad!

OzFTrucker

335 Series- 5.8/351M, 6.6/400, 351 Cleveland

17

Sep 27, 2013 10:09 PM

4180 mixture screws?

fordtime

Fuel Injection, Carburetion & Fuel System

2

Mar 16, 2004 11:34 AM

Reply Share

First
Prev
1 / 1
Next
Last

All times are GMT -5. The time now is 10:01 AM.