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Discussion Starter #1
Let me start with what I have replaced, The fuel tank, bolth pumps and bolth filters and the Fuel pump relay.

Now for the problem, If I leave the bronco sit overnight and turn the key it will run for about 1 second. If after it stalls i keep turning the key it feels like the engine is depleting all the pressure from the fuel rails and will just continue to turn over without getting any fuel. I can hear the Rear pump humming and the high pressure pump just seems to click. I know I might have gotten a bad high pressure pump, but are these the symptoms of that? Im really out of ideas on this one.:banghead

I almost forgot, If there is anyone in the Central Jersey area who isnt buisy Sunday i could really use some help..There will be a case of beer in it for ya. Or gas money.
 

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o[|||]o
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Have you checked for good pressure at the fuel rails?
 

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Discussion Starter #3
If i let it sit, it will have pressure, but it seems to have none after it does its whole 1 second roar.
 

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Practicing Infidel
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15,308 Posts
Sounds like classic vapour lock

or air in the lines. How well do your plastic lines seal and connect at their junctions ? Many times the bad seal isn't enough to actually leak gas, just let in air to the lines.

Sixlitre
 

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Practicing Infidel
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FireFighterMike said:
How would I go about ending this vapor lock?
Could be one of your plastic lines not sealing

Your fuel pressure is 43 lbs, not 6 ot 7 lbs pressure. A gauge on the valve and a watchful eye underneath I guess

Sixlitre
 

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Yeeeeehaw Y'all!
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FireFighterMike said:
If i let it sit, it will have pressure, but it seems to have none after it does its whole 1 second roar.
You need to put a gauge on the fuel pressure rail. That is really the only way you can tell what your fuel pressure is doing.

Saying it "seems" to lose pressure and "knowing" if it is or isn't are two entirely different things. You'll drive yourself crazy trying to diagnose things that "seem" to be working or not working.

Call AutoZone or another local parts store and see if they rent fuel pressure gauges. Get a gauge and quit guessing.

Then if you find you are losing pressure, take Sixliter's advice and start looking at the places in the line where it could be sucking air.

Have you tested the fuel pressure relay? It could be bad and kicking out after it heats up?

Is the fuel filter installed correctly?

Have you checked the voltage at the fuel pumps?

Not trying to be a smart @$$, but don't just throw parts at it.... throw smarts at it.

It's a system. Check each component and replace whats bad, not what you think is bad. That'll just un-necessarially cost ya lots of your hard earned money, give you high blood pressure, body dents, cut up knuckles, gray hair, and you still end up with a broke down truck.

Work smarter not harder. :thumbup



Edit: Oh yeah.... I seriously doubt you're experiencing vapor lock in Feburary.
 

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Discussion Starter #8
Yeah...that vapor lock wasnt it..i have almost no pressure on the fuel rails (its somewhere between 12-15 depending on how long i let it sit) bolth fuel pumps are working correctly and wow do i have pressure at the second filter after the high pressure pump.

I did find something interesting out tho...if i spray ether down the intake it fires up and reaches about 2k rpms and dies.

So i tried it again and as it died i pumped the gas, and while pumping it i can get it to jump from about 2-3k rpms and while doing this i have no vacuum pressure to the brakes, only when i pump the gas and the rpms come up do i get vacuum. Heres what im thinking......I have a serious vacuum leak somewhere and its not allowing the fuel pressure regulator to open normally...or at all...only when i force start it and keep the rpms high its getting vacuum and the fuel pressure reg. is opening and the motor is dieing immideatly due to the leak. Does this make sense to you guys?? It seems to me.

So tommorw..(or later on today rather) im goin to go vacuum leak hunting..i guess ill start with the bigger lines and work my way down.
Does anyone have a diagram of the vacuum lines and where they come from/go to??
thanks again
Mike
 

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Discussion Starter #9
Ok, I pulled the codes and actually got something today, i have a 21, 22, 24.

According to the haynes, Its

21- ECT Sensor out of normal range
22- Map sensor out of normal range
23- ACT or IAT out of normal range

Now that i have these, im kinda wondering my next step, As to why this truck wont run, if anyone has ne ideas please let me know.
 

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crank trigger
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I think you might be getting those because you can't get it to operating temperature.
If you have lots of pressure upstream, maybe there is some sort of blockage. Did you inspect the fuel lines all the way up to the rail?
 
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