random hard start 2002 mm 4.0
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random hard start 2002 mm 4.0
ok im having a random hard start condition. it will happen once a week or with no rhyme or reason. it turns over real nice but does not start until the second or third trythe last time on third try i push accel pedal to floor and it started. this hasnt happen in a few day so i cant tell you if the accel pedal will always help.
wayne
wayne
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plug and wires about 40k ago. I have FPG on now and the pressure is dropping from 64 to about 50 in a half hour which is not too bad in my experience will check the plug next time it happens. I might have smelt fuel last time in no start condition but not sure. if it is not a fuel issue what would be your next step be in trouble shooting?
wayne
wayne
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What is acceptable fuel pressure after an a few hours of sitting it leaked down to about 30psi after about 2 hours it runs at about 64 when running what do i need besides a Fuel gauge to test the fuel system?
wayne
wayne
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From: Cedar Rapids, IA
Keep trying the throttle all the way to the floor to see if that gets it to start reliably on the second or third crank. Going Wide Open Throttle (WOT) causes the fuel injectors to stop pulsing. This mode is also referred to as the "Clear Flood" mode because it can be used to clear out excess fuel in the event the cylinders get flooded with fuel.
The fuel pressure leakdown rate does not seem unreasonable, but I cannot say that I've ever left a gauge on my truck for 2 hours to see what it gets down to.
Another thing to try would be to hold the throttle just slightly open when cranking the engine. Maybe the passages for the idle air control are restricted, although you don't mention any issues with stalling when the electrical load is high, the steering is turned, or the A/C compressor clutch engages.
-Rod
The fuel pressure leakdown rate does not seem unreasonable, but I cannot say that I've ever left a gauge on my truck for 2 hours to see what it gets down to.
Another thing to try would be to hold the throttle just slightly open when cranking the engine. Maybe the passages for the idle air control are restricted, although you don't mention any issues with stalling when the electrical load is high, the steering is turned, or the A/C compressor clutch engages.
-Rod
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no other than a random hard start condition i have no other issues included in this problem what does that mean for trouble shooting if the wot helps start on a regular basis during this problem
wayne
wayne
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From: Cedar Rapids, IA
It would suggest that at least a few cylinders are getting too much fuel which could point to something as simple as a bad Engine Coolant Temperature (ECT) sensor or possibly a few fuel injectors that are leaking. The slow rate at which your fuel pressure drops though would mean the injectors would not bet at the top of my list. There may be a few other sensors (MAF, IAT, etc) as well that could have an impact on cold start pulse width.
-Rod
-Rod
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From: Titusville, FL
Do you hear the fuel pump build pressure - pump runs for 2 to 3 seconds - each time you turn the key on prior to an attempted start? If the fuel pump is intermittent that could be your problem. I had a similar problem with my 94 Explorer. The first test performed was a pressure leak down test at the fuel rail to confirm the system was holding pressure. Sometimes it would take several key on/key off sessions to get the pump to pressurize the system. The fuel pump was building engine starting pressure intermittently. It was replaced AND the problem disappeared.
Prior to installing the new pump, after engine start, I never had a problem with engine stalling due to fuel starvation. That was one symptom I thought would show but it never did. GO FIGURE!!!
Jim
Prior to installing the new pump, after engine start, I never had a problem with engine stalling due to fuel starvation. That was one symptom I thought would show but it never did. GO FIGURE!!!
Jim
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