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Engine Running Poorly
#1
The last few days the car has been running poorly.
Long story short, we went through the ignition
system and could not find a problem. No matter
where we set the timing, the engine ran rough. All
wiring is intact. Bought new electronic points to replace
the "suspect" set. No change. So we started looking
at fuel delivery. Fortunately my Holley has fuel level
windows. With the windows at half (which is good) we
started the engine. The fuel level dropped and did not
return. The car would idle but if you tried to drive it....
My mechanic thinks it is the fuel pump. Could be a
clogged filter. A new SS 3/8 inch fuel line was installed
a couple weeks ago from tank to pump. We checked all
the connections. What I thought could develope into a
major repair job turned out to be a $19 pump. We will see.

mike

[Image: 1_11_11_13_11_50_27.png]
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#2
Let us know, Mike. It did sound like the pump from your post.

Doc

[Image: 6y14ea.jpg]

Project started 8-7-10
Completed: All new suspension, rebuilt 351C H Code bored .030 over with mild cam and intake, new 3.50 TracLok, custom exhaust system
Current "mini-project": interior upgrade Undecided
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#3
Fingers crossed it's the pump. Based on my limited knowledge, it certainly sounds like it's the problem.
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#4
73vertproject;126744 Wrote:Let us know, Mike. It did sound like the pump from your post.

Even though I would like to drive my car, I do enjoy the hunt.
If that makes any sense.

mike

[Image: 1_11_11_13_11_50_27.png]
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#5
Definitely could be the pump, fortunately they take 25 mins to change out and they are super cheap. They really don't go bad though, if ever.
The only other thing (if fuel is in fact the issue) could be a clogged sending unit in your tank. That's another cheap part but really that's about it (other than the filter of course).

Did you try spraying starter fluid in the carb while it was running to verify that it's a fuel delivery issue? If you spray fluid and it runs / idles fine then it's fuel delivery...if it runs the same then it might be your spark is jacked up.

KR

-Former 70 & 72 Mustang Owner.
-69 Torino GT, Formal Roof, 351W, Edelbrock 600 cfm, Edelbrock 351W Performer RPM intake, headers, AOD trans, dual flowmasters w/H pipe, Pertronix II Billet, 3.5 TRACLOC g/r, 15" Magnum 500s, 100A alt, aluminum radiator, electric fan, Pro-car seats, mini-starter...owned since Dec 13.
-70 Mach 1, 351W, Edelbrock E-Street EFI, VHX instrument cluster, Hooker headers, dual flowmasters, Pertronix II, 15" Magnum 500s, 150A alt, aluminum radiator, dual electric fans, Pro-car seats, mini-starter
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#6
73vertproject;126744 Wrote:Let us know, Mike. It did sound like the pump from your post.

+1
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#7
RobbMc is selling Cleveland pumps again. Hand built with good components and rebuildable. Cheaper model is for up to 550hp.
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#8
What was the condition of the fuel tank, was the fuel sender taken out and at least the filter sock cleaned. I don't remember if you had changed the tank or not. But if you have junk in the tank it would re clog the system.

One other thing... Remote possibility if the fuel vapor system is clogged which it can be it will cause feeding problems.

Start the engine get it running confirm its running poorly, then go open the gas cap and leave it off, see if the engine suddenly runs better.

If the vapor line is clogged with varnish it will cause vacuum in the tank and reduced flow to the carb and it would mask as a bad fuel pump.

For the fuel pump , check your oil, if it smells of heavy gasoline then you know the pump is leaking and no good.

It could be the fuel pump as well and that is a pretty easy change. But you want to make sure you don't have other issues.

If the vent is clogged and the tank was never changed I wouldn't screw around I would just replace the tank and sender and replace the vapor line to the charcoal canister at the engine bay.


Just to give an idea when I replaced my fuel system and took the original vapor line out it was 100% clogged with varnish goo, and the rubber hose connection above the tank had split from age allowing a vacuum. Not to form in the tank.
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#9
+1 on 72HCode. That's sound advice.

-Former 70 & 72 Mustang Owner.
-69 Torino GT, Formal Roof, 351W, Edelbrock 600 cfm, Edelbrock 351W Performer RPM intake, headers, AOD trans, dual flowmasters w/H pipe, Pertronix II Billet, 3.5 TRACLOC g/r, 15" Magnum 500s, 100A alt, aluminum radiator, electric fan, Pro-car seats, mini-starter...owned since Dec 13.
-70 Mach 1, 351W, Edelbrock E-Street EFI, VHX instrument cluster, Hooker headers, dual flowmasters, Pertronix II, 15" Magnum 500s, 150A alt, aluminum radiator, dual electric fans, Pro-car seats, mini-starter
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#10
1. Have you checked timing to assure advance is working properly?

2. Fuel Pump Test- Disconnect anywhere after fuel pump but before filter. Install long rubber hose on fuel pump side of disconnect, put other end into a milk carton. Crank car and see if you have fuel. If you have fuel, add fuel filter and see if you can pump gas past filter.

3. If you are really adventurous, count the cranks and see how long it takes to fill up the milk carton. That way if you do replace the fuel pump, you have a basis for volume delivery.

[Image: 11jmcuc.png]
351C Bold Manners, Brash Attitude
Favorite Teams: Michigan Wolverines and Whoever Is Playing Ohio State.

When I drive past a herd of cows, the cows MOO at me
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