Rough Idle HELP

[mcfoss1]

I have a 1999 4.0 SOHC with aftermarket exhaust and CAI that has a rough idle. It has stalled a couple times on start up and also has the timing chain "tick" in one of the front chains. When driven it feels as if it has lost power and gets horrible fuel mileage now. No CEL codes and no lights on. I have done the small stuff such as cleaning MAF, IAC, Throttle body, and I have checked for vacuum leaks in all the places I can get to. It does have new spark plugs but wires are not new.

If anyone has any tips or wants to put their input in it would be real nice. I am new to here so if I am posting in the wrong section sorry!

 

[explorer-aus]

Changed simple stuff like fuel filter? Or run some injector cleaner through it for a little while? If they havnt been changed your leads might be due. Although if you really are having timing issues, maybe the slack chain is effecting it.

What is it like under heavy load, eg. up a big hill?

 

[mcfoss1]

Fuel filter is fairly new. All the small stuff has been done such as seafoam in fuel and intake through IAC hose. Under load it struggles a lot compared to what it used to. Also fuel mileage has gotten horrible.

 

[99XLT-Explorer]

i know this sounds stupid but check the plug at the back of your coil pack see if its plugged in all the way my wiggled out and ran terrible. also is it only when its cold?

 

[mcfoss1]

No it idles bad when it is both cold and warm but worse once it warms up. If give it a little gas when it comes back down to idle sometimes it will act as if it is going to stall.

 

[99XLT-Explorer]

sounds like a iac (idle air control valve)

 

[mcfoss1]

IAC is good. I unplugged it while it was idling and it caused the explorer to stall out meaning the IAC is doing its job. But if the IAC were faulty would it still work partially?

 

[mcfoss1]

Took it to a local mechanic and they could not find anything wrong with it. He said it could be a coil pack but I don't really want to blow $80 and find out that it's not the problem! Any ideas?

 

[2000StreetRod]

fuel pressure?

Ford Explorer Ranger Fuel pressure test procedure

 

[mcfoss1]

Fuel pressure was fine already checked it.

 

[mcfoss1]

Put a new battery in after i tested mine and it was bad. It starts a lot smoother and idles a little better but still not impressed yet. still has a "miss" to it. any ideas?

 

[2000StreetRod]

Techron?

You might try adding a container of fuel injector cleaner to your fuel tank. I only use Techron.

How did the spark plugs look when you changed them? What brand of plugs did you install? Some members have experienced problems with Bosch plugs. Did you connect the plug wires correctly? It is common for members to accidently swap cylinders #5 and #6. The coil connections are not numerically sequential. The cylinder numbers should be marked on the coil pack.

Have you performed a compression test?

 

[mcfoss1]

Injecter cleaner doesn't help tried many different ones and have ran seafoam through it many times. Double checked all plug wires and just changed them Friday and didn't really change anything. I have not ran a compression test. I will do one soon enough. It is just very difficult to get the passenger side plugs out and hard to find the time to set aside toget them out! Haha but the old plugs looked fine when I changed them.