Hard start and low idle

[Juustino102]

So i have a 98 ford explorer 4.0 efi. When i start it up cold it takes a long time fireing up . Seems like battery light flashes when i do then it fires up and when stoped at light and i have the clutch in it idles normal then drops down. When i stop for gas and turn it off when warm it fires right away. But if i leave it alone for a hour or so. It takes a bit to start. I dont know what could be causing this. I havnt done anything indepth. But id like some suggestions or if someone had this problem before and fixed it and could help that would be great.

 

[4D X]

Clean/replace IAC valve

 

[Juustino102]

That would cause a hard cold start?

 

[Juustino102]

I also have the code p1151 and i know i have a few messed up vaccume lines but this happed after i hooked my vaccume line back up to the line that changes where the air blows

 

[Flash]

As mentioned: clean the IAC valve. Yes, that would make it hard to start.

Also check for vacuum leaks and fuel delivery problems - filter, check valve, pressure etc.

Low idle would indicate the IAC.

 

[Juustino102]

Cleaned iac and idle smoothed out. Just have the hard cold start

 

[J_C]

Is it turning over at good speed or slow?

If slow, how's the battery? Possibly dying and/or drained from a bad alternator? Sometimes they get a diode leak and drain the battery when off, or there could be another parasitic battery drain somewhere which you could measure with an ammeter/multimeter.

I'd lean more towards bad battery IF it's one of those two because if the drain were enough to make it hard after an hour, it'd probably be impossible to start after sitting overnight, but it could be something as simple as battery cable corrosion.

 

[Juustino102]

Idle went back down and well iv cleaned battery multiple times. Ill go find new battery and test it. Also could having missing vaccume lines cause it?

 

[J_C]

^ No point in wondering about the vacuum lines' effect. They need fixed then go from there. That will definitely affect the idle quality (assuming a leak, not plugged because you removed *something* deliberately) and could cause trouble starting as well as the diagnostic code p1151, but so could other things.

 

[chefduane]

Upper/Lower Intake Manifold gaskets. Search the site, many posts on hard cold starts due shrunken and fatigued mani gasket sets.