Fuel Delivery Problems - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
Ford Forum Ford Forum

» Auto Insurance
» Featured Product
ยป Wheel & Tire Center

Go Back   Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > The Garage - Tech Forums > Engine Specific Tech > Cleveland Tech
Register Home Forum Active Topics Photo Gallery Auto Loans Garage Mark Forums Read Auto Escrow

FordForums.com is the premier Ford Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
Old 08-02-2006, 15:20   #1 (permalink)
Registered User
 
Join Date: Jan 2005
Location: Brisbane
Posts: 181
Fuel Delivery Problems

I currently use a holley black pump with half inch line from a fuel cell. This goes to a mallory by-pass reg, half inch line back to cell. From reg to carb half inch line as well. Carb is a 850 ad mighty demon.

The problem is it runs well till half track high 7.2 secs but then about 1000ft mark it runs out of fuel. I have to feather the throttle to get fuel back to the carb.

Its very disappointing when your speed at half track is higher than at full track. I am hoping someone may shed some light on this problem.
xw383 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 08-02-2006, 23:58   #2 (permalink)
74 XB Fairmont
 
brenx's Avatar
 
Join Date: Sep 2001
Location: Cranbourne, Vic
Posts: 5,113
Re: Fuel Delivery Problems

Very hard to diagnose with too little info. More info needed please

Do you have a breather in the cell? A 1/2" one.

Where is the fuel pickup located? At the back I gather?

Where is the pump mounted? At the back under the car? It should be as close to the fuel pick up as possible.

Do you have a filter between the cell and pump? If so what type? Normal filters aren't designed to work as prefilters. Normal filters are designed to work under pressure. If you have a normal filter? You'll need to buy a good prefilter.

What fuel pressure are you running? 5 3/4psi should be plenty if set at idle.

I had the same issue as you when I used a factory tank with the pickup at the front. Fuel was moving away from the pickup and I was getting a line full of air. Hence me moving to a cell and now I've got a modified stock tank which works very well.
__________________
XB Fairmont (street car) 11.07@123.02mph.
brenx is offline   Reply With Quote
Old 08-03-2006, 01:20   #3 (permalink)
Registered User
 
Join Date: Jan 2005
Location: Brisbane
Posts: 181
Re: Fuel Delivery Problems

G'day brenden, fuel pick-up at back, breather 1/2 inch, fuel filter similar to A1 performance filter ( can't remember brand ), fuel pressure has been tried anywhere from 6-9 psi, fuel pump is mounted in the arch just behind diff. We have done a free flow test with this pump and a holley blue no problems there. I am thinking possible voltage drop at full power, maybe renew wiring and fit relay. If you want to go fast the money tree better keep growing.
xw383 is offline   Reply With Quote
Old 08-03-2006, 01:36   #4 (permalink)
74 XB Fairmont
 
brenx's Avatar
 
Join Date: Sep 2001
Location: Cranbourne, Vic
Posts: 5,113
Re: Fuel Delivery Problems

If you don't have a relay fit one. Otherwise you'll be running lower voltage than you should be. Your pump may need repositioning. Keep the pump as close to the pickup as possible. Holley pumps fullstop aren't all that good in my experience. You get some good ones that'll suck fuel from anywhere without any issues yet others won't suck fuel from 12" away from the tank.

Best one I've seen to date was mounted in the engine bay! This was in a torana.
__________________
XB Fairmont (street car) 11.07@123.02mph.
brenx is offline   Reply With Quote
Old 08-03-2006, 07:09   #5 (permalink)
Registered User
 
TruBlu351's Avatar
 
Join Date: Apr 2003
Location: Newcastle
Posts: 2,398
Re: Fuel Delivery Problems

Old crappy fuel filters on the pressure side can also block fuel flow.

Does you cell gravity feed into the pump or does it have to suck it up first?
__________________
XE Falcon
393 Tremec TKO 9"
TruBlu351 is offline   Reply With Quote
Old 08-03-2006, 12:19   #6 (permalink)
Registered User
 
Join Date: Aug 2005
Posts: 330
Re: Fuel Delivery Problems

Quote:
Originally Posted by xw383
fuel pressure has been tried anywhere from 6-9 psi, fuel pump is mounted in the arch just behind diff.
That pump sounds a bit too high? Too far above the tank. I have no experience with the black pump but I would mount it low enough for fuel to gravity feed into it. Remember when the car is accelerating fuel is going to the back and bottom of the tank as well. Even if the pickup is there the pump has to siphon from the back/bottom of the tank up to the pump first. It's a difficult task for it.

Do Holleys have special needle/seat that allow you to run 9 psi?
northey is offline   Reply With Quote
Old 08-04-2006, 00:00   #7 (permalink)
Registered User
 
Join Date: Jan 2005
Location: Brisbane
Posts: 181
Re: Fuel Delivery Problems

Thanks for the replies everyone. I have a cell thats sits in the boot area and it does gravity feed to the pump. In the arch the pump is mounted approx 1/4 way up the cell. ( height wise).
Northey not sure what you mean (needle/seat 9 psi). The holley black is basically designed for methanol. Which i am definately not running or going too. Looks like i will be doing a rewire. Bugger !!!!
xw383 is offline   Reply With Quote
Old 08-04-2006, 14:10   #8 (permalink)
Registered User
 
Join Date: Aug 2005
Posts: 330
Re: Fuel Delivery Problems

Quote:
Originally Posted by xw383
Thanks for the replies everyone. I have a cell thats sits in the boot area and it does gravity feed to the pump. In the arch the pump is mounted approx 1/4 way up the cell. ( height wise).
Northey not sure what you mean (needle/seat 9 psi). The holley black is basically designed for methanol. Which i am definately not running or going too. Looks like i will be doing a rewire. Bugger !!!!

My bad. I incorrectly assumed your cell was lower than that.

Like my answer to above this has nothing to do with your problem either; it's just a question. I thought that Holley's could only cope with 7 psi max pressure before the float spring couldn't overcome the fuel pressure. Hence the quiz about 9 psi fuel pressure?

cheers
northey is offline   Reply With Quote
Old 08-04-2006, 14:47   #9 (permalink)
Registered User
 
Join Date: Jan 2005
Location: Brisbane
Posts: 181
Re: Fuel Delivery Problems

In the carby i also run methanol needle and seats.( .150) We had this problem with a holley blue, then went to the black. Fixed that, then found out camshaft stuffed, put a new one in from John at CHI , Fixed convertor now problem has reappeared. I'm yet to have a full power pass yet.
xw383 is offline   Reply With Quote
Old 08-04-2006, 17:48   #10 (permalink)
Registered User
 
Join Date: Aug 2005
Posts: 330
Re: Fuel Delivery Problems

do those pumps have a relief/bypass valve in them? They can jam or be sticky at times. I only know blue pumps, never owned a black one.
northey is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > The Garage - Tech Forums > Engine Specific Tech > Cleveland Tech



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

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
Trackbacks are On
Pingbacks are On
Refbacks are On


Powered by vBadvanced CMPS v3.2.2

All times are GMT -7. The time now is 11:51.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.6.0
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.