Hard start issue.

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Daly

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My truck has had this issue since I bought it, and I initially thought it was a bad FPR. But I'm starting to doubt it now that I've started actually looking into it.
First thing in the morning after sitting all night or even for a week with out running the truck starts fine, fires right up. But once I get to work, and it sits for 4-8 hours, I have to crank it over excessively to get it to start (this makes me think FPR). But when I get it home and park it for a night or week, it'll start fine again. It's like the longer it sits the easier it is the start.
If the FPR diaphragm is bad, then the longer it sits that less likely the pressure is going to remain. It seems to be the opposite, if I shut it off for 15mins or even an 8 hour shift, it has to get fuel back to the injectors. But if I leave it for the night or week, it has fuel pressure and fires right up.
It's a 98 454, has anyone had this issue before or have an idea what else it could be. I'm going to replace the FPR anyway, as I have one, but if it could be anything else I'd like to do it at the same time.
 

BNielsen

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Does it cough out a cloud of unburnt fuel when you finally get it started?
Sounds like the injectors are going bad, very common on 7.4L Vortecs.
 

GreenZ98

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Man I hope you figure this out cause mine has the same issue. Cranks perfect in the morning as soon as you touch the key, but after work it may crank perfect or may spin and spin. May do it once a week, none or everyday. I've replaced fuel pump, injectors and fpr.
 

Daly

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Does it cough out a cloud of unburnt fuel when you finally get it started?
Sounds like the injectors are going bad, very common on 7.4L Vortecs.
I'm not getting any unburnt fuel, I'm going to test the fuel pressure when I get my gauge back, as soon as I find out which friend has it, and might replace the injectors while I'm at the FPR, I'll be staring at them while I'm there anyway.
 

east302

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Do you have a scanner? Check the readings for the coolant temperature sensor. If it’s bad, it’ll show some oddball number and it throws off the computer calling for too much fuel. A workaround is holding the gas to the floor while cranking. That stops injector flow.

Throttle position sensor would be another reading to check to see if it reports comparable to actual pedal position.
 
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