Wierd starting problem

[shofear3]

My 95atx starting having a strange starting problem about a week ago. What it does is every once in a while it will crank for about 5-10 seconds before it starts, and othertimes it starts right up? Once it starts it runs fine, and there are no codes. My 1989 f250 did this once and it turned out to be a fuel pressure regulator. Also anyone know how to clean the maf sensor. I have a K&N and I have been reading on this forum that the K&N oil can gumm it up. Thanks

 

[93SHO'nOFF]

Does it make a difference if you cycle the key a few times before cranking?If it doesn't then it's unlikelyto be a fuel concern.I use Choke Spray to clean out MAF sensors.
Later

 

[shofear3]

Does it make a difference if you cycle the key a few times before cranking?If it doesn't then it's unlikelyto be a fuel concern.I use Choke Spray to clean out MAF sensors.
Later

If I crank it for a second then stop and then crank it again, it starts right up. It usually happens when you drive the car then let it sit for an hour or so. other then that even on cold starts it fires instantly. Its got me puzzlled

 

[shoteen95]

weird, when my cars cold i'll have to crank for maybe 4 or 6 seconds to get it fired. starts like a champ when warm.

 

[93SHO'nOFF]

It seem's like fuel pressure is bleeding down when the car is off.The fuel rail is supposed to maintain pressure when the engine is off to minimize starting concerns.Thing's that can let fuel leakdown are;Leaking Injector,Fuel pressure Regulator,or a bad Check Valve in the Fuel Pump.
To test the FRP:
(1)Remove the return line and plug at fuel rail(a good fuel pressure gauge kit usually has addaptors in it to do this)
(2).Turn key on,check Fuel Pressure,turn key off,and watch pressure.
(3)Does pressure drop more than 5 PSI in 1 min?
YES-INJ or FP is bad
NO-If it maintains constant pressure,theFPR is bad.
To test the Check Valve on FP:
(1)Remove pressure line at rail and attach gauge to the pressure line.
Repeat(2) same as above.
Does PSI drop?
Yes-Bad FP
NO-INJ leaking down
Later,
Mike

The MAF sensor can also cause many drivability concerns,cleaning it is a good idea.

 

[shofear3]

Thanks, I will give it a shot this week.

 

[htheduck]

Not to hi-jack this thread, however I had a similar problem this week with a rough start that required 4-5 cranks (normals is 1-2 cold, 1 warm). THEN THE IDLE WOULD start to slowly pulsate between 900-1300 up and down. I gave it the gas to make it go away and they (once) it rose slowly to 2000 - which I then put it in gear and drove away with no problems. It happened again later on that night (warm start) and the pusating came back-I then gave it throttle and it whet back down to 900. Could this be also be contributed to switching from 93 - 87 octane gas for one tank? Or is there something more serious? This all happened shortly after pumping 87 for a full tank.
Any thoughts or ideas would be appreciated, thanks in advance.

 

[anarchy04]

I would give the fuel filter the blame for hard starting. Even if the pressure is bleeding off after and hour that is more than enought to get it to start, mine bleeds off pressure in like 5 minutes cause the threads aren't sealed on the FPR and it still only turns over twice before firing. Any ways what I'm saying is that the pump should easily beable to build up enough pressure even if the FPR isn't completely sealed but if the pump can't flow what it is supposed to beable to flow then it might have some trouble building up pressure right away. Usually you will notice some lost power up top too if it is plugged. Even if that isn't the cause it would be nice to know that it has been changed.