I'm STUMPED on this one???? Any ideas???

[FireZingr]

OK 2 days ago in weather about 15 degrees as I was warming up my 98 Exploder the check engine light came on and then all of the sudden it starts missing and sputtering. I immediately thought BAD GAS!!! so I drove on to work sputtering and knocking. As I am driving to work (7 miles) the check engine light begins to blink..... So when I get to work I check the owners manual and determine I have an emission problem so I go on about my day thinking OK could be bad gas maybe water in gas etc. etc.
After work I get a bottle of HEET dry gas and add to the tank thinking it should clear it up. 20 miles later still same missing sputtering knocking and flashing check engine light.
I drive to AutoZone and they put the code reader on it and it reads "Misfire in Cylinder 1" OK now I am thinking bad spark plug? Bad Coil? so I take it home.
Next morning start it up and she puuurs like a kitten so I think Hmmmm weird maybe it was bad gas. As the engine gets up to operating temperature BAM knocking pinging sputtering flashing light. (Has happened 2 times now when started cold it runs fine until reaching operating temp then starts misfiring)
OK So now I am leaning towards the coil as I had a motorcycle once that once got hot the coil would stop firing, let it cool down and she ran like a top.
Get home today and performed these steps......
Unhooked each spark plug wire one at a time from the coil
All 6 are firing at the coil like a lightning BOLT!
once I took the spark away from the plug wire the engine stalls on all 6 wires.
So what this is telling me is that the coil is just fine, the spark plugs are OK and all 6 are firing. right?

What could be left??????
All I can think of is Fuel Injector........
Filled it up with Exxon supreme and added STP Ultra Concentrated fuel injector cleaner to see if that helps.... Anyone else have any ideas???
I am lost??????

 

[corkey]

take the plug out and look at it too, could be the problem.

 

[FireZingr]

So it could be getting fire to the plug but just not enough to fire the cylinder completely???? Because I am pretty sure all the plugs are firing as each time I take a plug wire loose at the coil the engine stalls. All 6 of them do this meaning all 6 are firing and as I take one loose it loses fire in the cylinder correct?

Also am I correct that the #1 cylinder is the one closest to the radiator on the passenger side?

 

[2000StreetRod]

Which engine?

Yes, cylinder #1 is on the passenger side closest to the radiator. Is it an OHV or a SOHC?

Do you have a mechanic's stethoscope to listen to the injector or a noid light to test it?

The PCM identifies a cylinder as misfiring when the power output is low relative to the other cylinders. While the spark plug is firing the power output could still be low.

A single cylinder misfire is likely to be due to ignition, fuel injection or low compression.

I suggest that you replace the plug (not Bosch platinum) since it costs little and is easy. "Read" the plug you pull for abnormality. Check the cylinder compression while the plug is out. Test the fuel injector.

 

[FireZingr]

4.0 SOHC, I'll try the plugs this weekend as it will be the first chance I get for some shop time.

Do you have a mechanic's stethoscope to listen to the injector or a noid light to test it?

No and No LOL

 

[FireZingr]

What about the rattling sound? could that possibly maybe be a broken spring or something? Or is it just a result of the misfire?

 

[Eagleisx]

Misfire.

Try replacing the EGR valve,i had the same problem when the engine light came on and my truck started to run rough,that is the first and cheapest step as you can get one at the auto wreckers,if that fails then it could be your O2 Sensor or Intake Manifold Gasket.

 

[2000StreetRod]

Stuck EGR valve

The PCM checks for a stuck open or stuck closed EGR valve and should set a corresponding DTC. A sticking open EGR valve can result in misfires during cruise or acceleration and may not be detected by the PCM. The EGR valve is easily tested if you have a hand vacuum pump. You can disconnect the vacuum line to the EGR valve and plug the vacuum line to prevent the EGR from opening. If it is stuck open the engine idle should be rough. For more info see EGR System O&T

 

[ranger7ltr]

When was the last time you changed the fuel filter?

I might have missed it if you stated that was changed already but if you haven't changed it in a while pull it and see what the fuel from the inlet side of the filter looks like...

Also I don't know if you have a fuel pressure gauge but if you do check your Explorers' fuel pressure...If the MY is pre 99, the pressure should be ~40 psi...99-current the fuel pressure will[or should be] 65-72 psi...

Let us know what you find at the filter though...I suspect there is garbage in the filter restricting fuel flow and it started causing random misfires...

 

[FireZingr]

No it def not the fuel filter as I get plenty of acceleration and power I have changed the plugs-No change. The wires are fine all plugs have lightning bolts coming off of them LOL. So I have plenty of fire going to all 6 cylinders and fuel/pressure loss is not a problem as I still have plenty of acceleration and power BUT I still have what sounds like either something broken or a leak of some sort. It is the weirdest sound. Could it possibly be a lifter spring or maybe a rocker arm would it still run with one of those broken?
I can almost make myself think it sounds like a leak of maybe exhaust but when revved up it sounds like something broken inside the engine. I am at a total loss of ideas without just breaking down and taking this thing to a garage and letting them try to rape me LOL.
The weird thing is when the engine is cold (just started after sitting for a 8-9 hours) it runs and sounds just fine after it starts to warm up is when it starts misfiring and I can then hear the sound. This morning when leaving for work after sitting in the driveway for about 12 hours at 20 degrees it ran like a top for about 1/4 mile then today after work it had been sitting 10 hours in 30 degree weather I drove about 1/4 mile again before it started.
This thing has got me stumped?

Any Ideas???

 

[2000StreetRod]

plug & compression?

Did the plug from #1 cylinder look normal?

What was the compression?

 

[1998Explodasport]

Have you been losing any coolant?

 

[FireZingr]

Went back out and messed with it some more at almost exactly 2500 RPM the noise almost goes away????
Checked coolant it is filled to the top as it has been for over 2 years without any loss whatsoever.
Spark plug had been in for a LOOONG time and you could tell, the electrode had deteriorated due to it's age but other than that it looked pretty normal for it's age.
It is almost like a sound that you get with bad gas when it pings but then at other times it almost sounds as if there is a broken part inside the engine but it alos sounds like maybe a high compression exhaust type leak. It is really hard to pinpoint the exact sound because it sounds so different at different RPM's and from different angles around the truck (inside vs outside)

 

[explorerguy89]

test egr and maybe give a tune up

 

[FireZingr]

Also a smell like something is getting very hot coming from truck after I shut it off and get out I can smell it. Like maybe a hot Cat Converter??????????

 

[Runnin'OnEmpty]

Also a smell like something is getting very hot coming from truck after I shut it off and get out I can smell it. Like maybe a hot Cat Converter??????????

You can look at the cats and tell if one is hotter than
the rest. A plugged cat will get almost cherry red hot.

That's a possibility since it runs OK for awhile
when it's cold......

 

[corkey]

is it like rotten eggs smell near the tailpipe ?

 

[Wrench]

If you do a compression test, make sure the engine is at operating temp, all plugs are out, igniton system is disabled, battery is fully charged, throttle body is at WOT position, fuel pump is disabled and you do a full five compression cycles. I would not take the engine stalling when a plug wire is pulled to be a sound responce. Could be you have low compression all round. Most healthy engines will keep running with one cylinder down and loose some RPM.
Check your fuel pressure with a guage. Don't guess or assume it is at the right pressure. Start with the basics first.

 

[FireZingr]

is it like rotten eggs smell near the tailpipe ?

A little. I also notice it looks like the oil may be kind of thin BUT when I changed the oil a few weeks ago I mistakenly put in 10W-30 and I think it calls for 5W-30 doesn't it??

 

[FireZingr]

OK here it is running..... What do you think?
http://www.youtube.com/watch?v=cr7XlotqIIk