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89 bronco 5.0l turn key to on position. The second fuel pump or highpressure pump is loud. sounds like it has air in it. It will run with a little starting fluid. However it runs poorly, the idol goes up and down and feels like it is behind on getting fuel. I believe it may be a fuel pressure problem. I don't know if it the in the tank pump. I have replaced the high pressure with another used one and it makes the same noise. I've searched the forum and saw to check the fuel pump fuse and possibly the fuel regulator??? I'm not sure where that is and am thinking that may be my problem. any help would be appreciated
 

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When is the last time you replaced your fuel filter?
 

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I had the fuel filter off it flows fuel very well. I would say i replaced it maybe a yr ago. The fuel tank is the next thing to come down and be inspected, I am thinking that may be my problem. It sounds like afir and fuel are mixing at the high pressure fuel pump, its kind of loud and sounds like a curdling sound. My question i supose is this: Does the motor need the pressure combined from both fuel pumps? I'm thinking right now it is my fuel pump in my tank but i didn't want too pull the tank. Over 12 gallons of fuel in there at least. arghhh. Thanks for the help so far keep throwin ideas at me.
 

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The tank pump is for volume and the second pump on the frame is the pressure pump. I think I got that right. Anyways you can have flow but not enough pressure.
 

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The in-tank pump lifts the fuel to the reservoir so it's available to the frame pump, which makes the pressure. Yes, you need both, but no, the pressure isn't added.

Put a fuel pressure GAUGE on it.
 

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When you had the filter off did you try to blow through it? Your fuel filter should be changed every year anyways.
 

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That sounds like a plan!!! BUt

Steve83 said:
The in-tank pump lifts the fuel to the reservoir so it's available to the frame pump, which makes the pressure. Yes, you need both, but no, the pressure isn't added.

Put a fuel pressure GAUGE on it.

What Pressure am i looking for. 30+ pounds??? and i need to check it at the schrader valve right?
I'm not sure exactly where it is but i'm sure i can find it....
 

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Ok i'm getting a pressure checker tonite. Few questions so maybe i can get ahead of myself here. If say i am getting the correct pressure, which there is where i'm pretty positive my problem is. Do you think there is a possibility of a bad injector or two or three. and how would i check that or know. 2.) The inertia switch everyone is talking about. How do i reset this? 3.) It may also be my fuel pressure regulator i'm thinking?? Is that on the frame rail or under the hood?? Thanks alot for everyones help.
 

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it is okay to hijack a thread if its 4 years old?!

I am having similar problems with my 88 f150. I replaced all gaskets from heads-up, including plugs, wires, cap rotor, coil and a bunch of other items. Drove about 2k and parked it when i bought my powerstroke. I had the stroke in the shop so I pulled the 88 out again after sitting for 2-3 months. Started right up, and ran great. When I refilled the tank, I put a new fuel filter in. Eventaully it started erratic idol, idol lope to eventually it took 2-3 times to crank in order for it to keep running. even then you needed to idol up at stop signs because it was idoling so low and loping. Put a new fuel pressure regulator...no difference. timing from 7-12..same thing. Tried hooking the scanner and I would get "cannot bring engine over normal idol" All this happened within 2 weeks. I ended up parking it again for another 2 months and now it wont run by itself without starter fluid. I could get it to barely run if I were to continue tapping on the pedal, but it would ping. WOT or trying to idol it would not go. The tank and sending unit is almost a year old. Could it clog that fast to the point where I am having these problems? If its not the sending unit, or pump what other problems could it be? almost every sensor is new, and checked every sensor. They are all working.

At first I thought it was an intake leak but I did the propane trick and still no luck. It idoled better when i took the brake booster vacuum out, but thats because it would idol higher.

thanks,
Josh
 

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check your fuel pressure
pull codes
and clean your Idle air control motor/valve
 

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I have plenty of fuel up to the fuel rail, both pump and sending unit is working. I cleaned this idle/air vavle. Truck will not start, but runs with gas sprayed into tb.
Could a bad injector cause it to run start? The motor and injectors have about 70k, but at 40k i had to replace heads because the 8 cylinders exhaust valve cracked and seated. Could that have been caused by a bad injector? Been running gt40s with no running or idle issues before this
 
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