Brought to you in part by:

.

JC Whitney clearance center!
  Mustangsandmore Forums
  Ford Racing
  vacuum or power valve problem?

Post New Topic  Post A Reply
profile | register | preferences | faq | search

next newest topic | next oldest topic
Author Topic:   vacuum or power valve problem?
73STANG
Journeyman

Posts: 82
From: Lincoln, NE
Registered: Apr 2000

posted 04-05-2004 05:00 PM     Click Here to See the Profile for 73STANG     Edit/Delete Message   Reply w/Quote
My Mach I with the 351 Cleveland and 6-71 blower has develope a surge at idle. It will go from 400 rpm to 800 rpm and back. The boost/vacuum gauge reads about 14 at idle. I am running two of the 625 demon Jr carbs. It runs fine if I hold the accelerator at 1500 rpm, but nothing below. The car won't die at an idle, but it is close. What do you think is causing this? Thanks for the help.

Patrick

IP: Logged

Fastymz
Moderator

Posts: 20638
From: Reno Nv USA M&M#1240
Registered: Apr 2001

posted 04-05-2004 05:19 PM     Click Here to See the Profile for Fastymz   Click Here to Email Fastymz     Edit/Delete Message   Reply w/Quote
I'd look for a Vacuum leak.

------------------
SCOOP

oddly obsessed with big scoops on little Mustangs

65 coupe,351w,C4,Big Boss 429 hood scoop,8" 3.40 TracLoc.

My Pics

IP: Logged

73STANG
Journeyman

Posts: 82
From: Lincoln, NE
Registered: Apr 2000

posted 04-05-2004 06:08 PM     Click Here to See the Profile for 73STANG     Edit/Delete Message   Reply w/Quote
A vacuum leak is the way I was leaning. What is the easiest way to find one without spraying anything all over the manifold and carbs? I don't have any vacuum going to the transmission. I don't think the brake booster is leaking. Could a bad PCV valve make the idle surge?

IP: Logged

N266fords
Gearhead

Posts: 1652
From: Sierra Vista ,Az USA
Registered: Apr 2003

posted 04-05-2004 06:24 PM     Click Here to See the Profile for N266fords   Click Here to Email N266fords     Edit/Delete Message   Reply w/Quote
since your set up has the carbs on to of the blower I would think of a power valve fail ure if equiped also high float level or stuck needle and seat. Bruce

IP: Logged

All times are ET (US)

next newest topic | next oldest topic

Administrative Options: Close Topic | Archive/Move | Delete Topic
Post New Topic  Post A Reply
Hop to:

Contact Us | Mustangsandmore Front Page

Copyright 2005, Steve LaRiviere. All Rights Reserved.


Ultimate Bulletin Board 5.47d

Amazon Honor System Click Here to Pay Learn More

[Acronyms][Calendar][Chat][Classifieds] [Members' Pics]

[ Mustangsandmore.com Bookstore] [ Smokin' Fords] [Tech Articles]