4.0 ohv staring problems

[Luis Manosalvas]

Any one with the 4.0 OHV engine? Searched but found nothing.
I'm having trouble with the engine staring first time I turn on the ignition it cranks and does start the second time I triedy it starts fine the engine idles fine and runs fine it's just having trouble starting when cold.

 

[poker4me007]

Assuming no codes,
How old are your spark plugs?

 

[Luis Manosalvas]

Tell you the truth I don't know I bought he used.. Going to swap sparks next week. Thanks

 

[410Fortune]

factory plugs and a good set of wires, do not get the cheap wire set from auto parts store, they do NOT LAST!!
Try priming the fuel pump a couple of times before you first bump the key, see if that helps it start more quickly.
If it does it may be a weak fuel pump = check fuel rail pressure so we can rule that out.

 

[AP9]

Check your IAC valve too; it could be fouled or have a bad gasket.

 

[lobo411]

How many miles? What year?

 

[Luis Manosalvas]

Check your IAC valve too; it could be fouled or have a bad gasket.

Check it it has No gasket hopfuly thats the problem.

 

[Luis Manosalvas]

How many miles? What year?

2000 4.0 ohv with 111060 miles

 

[Luis Manosalvas]

UP DATE: put on a gasket on the IAC stillba lil hesitant to start but not as bad as before its much better next are the plugs.... Thanks everyone for the help.

 

[lobo411]

Sounds like you're making some headway. I kinda doubt the IAC has anything to do with starting the car--by definition it's not a factor until the engine has started and is trying to regulate the idle. Plugs and wires could help.

I asked about miles because every time I've had a weak start it turned out to be the fuel pump. 120k is a bit low to immediately suspect the pump, but it's worth testing the fuel pressure at first start.

Or if you want to do an easy test: turn the key to start, but don't start the car. Just let the fuel pump prime the line. Repeat once or twice more to build up fuel pressure, and THEN start the car. If it starts right up, I'd be suspicious that the fuel pump is on its way out.

 

[Luis Manosalvas]

Sounds like you're making some headway. I kinda doubt the IAC has anything to do with starting the car--by definition it's not a factor until the engine has started and is trying to regulate the idle. Plugs and wires could help.

I asked about miles because every time I've had a weak start it turned out to be the fuel pump. 120k is a bit low to immediately suspect the pump, but it's worth testing the fuel pressure at first start.

Or if you want to do an easy test: turn the key to start, but don't start the car. Just let the fuel pump prime the line. Repeat once or twice more to build up fuel pressure, and THEN start the car. If it starts right up, I'd be suspicious that the fuel pump is on its way out.

I tried priming the pump and still had the problem ether way going to test the fuel pressure. I have a suspicion it has a cheap fuel pump. I bought the Ex used and was tould she had a new pump... I hope its just spark plugs or some thing simple cuz lowing that tank is going to be a pain lol.

 

[410Fortune]

lowering the tank is not that bad, its actually pretty easy in a Gen II Explorer

 

[Luis Manosalvas]

Update... I disconnected the MAF sensor.... It didn't cut off so most probably I have a bad MAF... Funny thing never had a check engine light. Plus I can't scan it anyways I plug in ny scan tool and it doesn't connect.