2002 V8 running badly

[alpha141]

Hi Guys,

Im new to the explorers and this one has been giving me a few headaches.... started running rough a short time after I got it, error codes were miss fire cyl 8 and random miss fire.

I have changed all the spark plugs, the coil on cyl 8 was failing so that got replaced as well. ran really good for a couple of days then started to miss fire again, cyl 5 this time. I changed that coil but it is getting worse but no error codes anymore. The miss fire is really bad under load. There is also a new problem thats just started too, driving along an the dash will do a warning beep every so often, at night I could see a VERY quick flash of the charge light, also when the engine is has been idling for a couple of minutes it will sometimes just completely cut out, also a new problem.
I am sure there has to be a common cause, but buggered if I know... any help would be greatly appreciated.

 

[SyberTiger]

Read the following thread just to make sure you don't have this problem because it is VERY common: Rough idle and "Check Engine Soon" light

 

[alpha141]

OK here is where I am up to... I have checked for vacuum leaks, there is none. The elbow next to the idle speed control valve is fine. Have also checked manifold vacuum when engine is running and it is rock solid (cant remember what the value was tho).

I have blanked off the EGR so no exhaust can flow into the manifold in case the EGR system is faulty. I havn't been able to take it for a drive just yet to see how it drives. It is idling nicely however it still will idle for a while (5 minutes or so) then just suddenly cut out and still no fault codes.

I really want to know what will cause the engine to just cut out like that.

thanks.

 

[SyberTiger]

I see that you have not given details on the year or configuration or your Explorer. You may want to edit your profile to fill our your vehicle specs so that others can help you out better.

Regarding the engine cutting off does it cut off like when you turn the ignition switch off? That may be a clue. Regarding the backfire issue I seem to recall that vehicles with traction control (AdvanceTrac) the system, under certain traction conditions, will purposely retard the engine and a backfire may occur.

Some error codes are not a part of the standard vehicle error code log. For example, ABS codes are stored in the ABS module. Thus, you have to do a vehicle specific code scan. If the code scanner you used doesn't require you to provide YEAR, MAKE, MODEL, etc. then it's only reading out standard error codes since it doesn't know about other modules your vehicle may contain. Where/how did you do the original scan for error codes?

 

[alpha141]

I see that you have not given details on the year or configuration or your Explorer. You may want to edit your profile to fill our your vehicle specs so that others can help you out better.

Regarding the engine cutting off does it cut off like when you turn the ignition switch off? That may be a clue. Regarding the backfire issue I seem to recall that vehicles with traction control (AdvanceTrac) the system, under certain traction conditions, will purposely retard the engine and a backfire may occur.

Some error codes are not a part of the standard vehicle error code log. For example, ABS codes are stored in the ABS module. Thus, you have to do a vehicle specific code scan. If the code scanner you used doesn't require you to provide YEAR, MAKE, MODEL, etc. then it's only reading out standard error codes since it doesn't know about other modules your vehicle may contain. Where/how did you do the original scan for error codes?

OK will put some specs in my profile. However it is a 2002 XLT explorer 4x4 auto with 4.6L V8. Yes with the engine cut out its as if the ignition was turned off but without anything losing power like what I would expect with a faulty ignition. I am able to immediately restart the engine. When it cuts out I get the charge light and low oil pressure lights come on and the dash starts beeping. When scanning for errors I am only able to scan for ECU DTC.

 

[alpha141]

OK an update....
Have already replaced 2 coils.
New spark plugs
Replaced crank position sensor
No vacuum leaks.
cleaned MAF
No ECU fault codes


current symptoms:
idles fine, cuts out randomly when engine is warm, there is no shudder or big change in revs, just stops.

Very bad miss fire when trying to accelerate or go up a hill.

I would have thought that a miss fire caused by weak spark would be picked up by the ECU like it did for the two that I replaced? Or is it just a case of the other coils are just failing ?

 

[JasonBourne]

I was having a simliar issue. I took it in to Ford and they found that it was a vacuum leak that I had missed. Cost to fix was 160.00. Running like a champ now.

 

[2002GreyHD150]

a few things to consider:

* a full set of upgraded coils from Pro Comp on eBay called "striker coils" when they have them $125-150 for a set of 8. Better than the OE better than the MSD's they are clones of for 1/3 the $$. you are what, roughly $90 in 2 coils now? Just do them all, call it a day.

edit: another vendor offering the coils:

http://www.ebay.com/itm/Ford-4-6L-1...es&vxp=mtr&hash=item45f55980bc#ht_1859wt_1037

* do NOT do platinum plugs... waste of $$

* 02-03 4.6's are notorious for crazy vacuum leaks wwith all the various elbows, caps, lines etc.

* Fuel filter will cause most if not all of your problems. If its never been replaced, be sure to get the METAL fuel line tool not the plastic one. The first time the lines come off the filter its a b*tch to get the lines to release. Put the metal tool on and give it a good "TAP" with a hammer or the back of your lifetime warrantied ratchet...

* Clean the Throttle Body, Intake Elbow, and IAC solenoid.

Go to your fave autoparts store ask for the Throttle body to intake elbow gasket, $3, the EGR metal shim gasket, $6, and the IAC gasket (don't know price my MOnty hs the IAC part of the TB) get a brass 5/16" to 5/16" barbed fitting, (2) small hose clamps, get a can of CRC brand TB and MAF cleaner, a can of brake cleaner, some towels, and a can of PB blaster. Have a full afternoon free.

First spray the EGR heat tube with PB blaster. Next remove the airbox and duct to the Throttle Body (TB) unplug the TPS and remove the throttle cable. Unbolt the TB from the elbow. Next undo the EGR tube, remove the EGR itself. Now take a couple lil pairs of Vise Grips and pinch the water lines to the PCV port on the elbow. install the barbed fitting and by pass the PCV water thing... its worthless anyway. Now remove the Elbow & cover the top of the intake opening with tape or a couple towel.

Move the TB and Elbow over to the bench away from painted surfaces.

Use the TB/MAF cleaner on the TB & IAC solenoid (there is supposedly some special coating that will flake off). Clean it until you can see yourself in the throttle blade. It will be covered in soot, oily stuff, and gunk.

Use the brake cleaner on the Elbow. Same thing... squeaky clean.

Inspect the tip/cone of the EGR, since it will be all sooty and black, wire brush it shiny. blow everything off with compressed air.

Remove the towels or tape on the intake opening, a light rub of engine oil on the elbow to intake rubber seal. Install the Elbow. Install EGR, put anti-seize on the tube threads. New gasket for TB and button up...

this long description completely changed the drivability and performance of our Monty. The TB and Elbow get all gummed up and eventually the truck will stall and stumble all over itself.

* be sure after any basic or serious work, you disconnect the battery for at least 30 minutes... better over night.. Just disconnect it when you start the work, you will be fine.

* 02 sensors: the (2) closest to the engine are the ones you are concerned about. the down stream ones barely get worn. If you are over 60-80,000 miles buck up the $80-100 for the top pair. Be prepared to cuss getting them out. Be sure to use anti-seize on the new ones.

* be sure to inspect the main power cable going from the battery under the engine over to the starter for frays/chafing, shorts. you would be amazed how crazy electrical gremlins can be on a major power cable... plus, its important to check that tis not rubbed through.

That should cover the main list of possible suspects and have you back in top running shape.

Rob

 

[SyberTiger]

alpha141,

Do you have an update for us yet on this issue?

 

[alpha141]

Not as yet. I have cleaned the throttle body, but I am waiting for the new coils to arrive. I wish I had see the link to striker coils before I paid for the motorcraft ones... I pretty much have to get all spare parts from the US, locally sourced parts are very expensive. I am hoping the coils will arrive early next week.

 

[dmckeever]

Not as yet. I have cleaned the throttle body, but I am waiting for the new coils to arrive. I wish I had see the link to striker coils before I paid for the motorcraft ones... I pretty much have to get all spare parts from the US, locally sourced parts are very expensive. I am hoping the coils will arrive early next week.

I notice this is a December/2011 post!
Any update?

This very same problem has plagued me for nearly a year now! Same symptoms as listed in thread; missing on throttle up and under slight load, idles for a period (few minutes) then suddenly quits. The missing at driving speed (80 km/hr seems to be a magic number) can be quite severe, and appears to be just like described above... as if the key was turned off for a moment (half second or less).

Finally got a code the other day 1386 Variable Cam Timing Overadvanced (bank #2). This doesn't seem to have anything to do with what's described above!

So... again... any update on your issue after getting your coils and doing other items suggested?

2002 XLT Explorer 4.6 V8

 

[alpha141]

it took a few months to get the coils from the USA. Put the new ones in and now its running very well. not having any problems with missing or cutting out.

 

[dmckeever]

2002 XLT Explorer 4.6 V8

I notice this is a December/2011 post!
Any update?

This very same problem has plagued me for nearly a year now! Same symptoms as listed in thread; missing on throttle up and under slight load, idles for a period (few minutes) then suddenly quits. The missing at driving speed (80 km/hr seems to be a magic number) can be quite severe, and appears to be just like described above... as if the key was turned off for a moment (half second or less). Except as noted below, there are no engine codes.

Finally got a code the other day 1386 Variable Cam Timing Overadvanced (bank #2). This doesn't seem to have anything to do with what's described above! (Replace camshaft & crankshaft sensors)

So... again... any update on your issue after getting your coils and doing other items suggested?

Well... an update from me.
Have now replaced:

• Fuel Filter

• IAC Valve

• Camshaft sensor

• Crankshaft sensor (this replacement was a lesson in eternal patience)

Still have exactly the same problem as described in this thread. It's been several thousand kilometers since the engine cutout problem began; doesn't seem to get worse (it's bad enough at times), and certainly isn't fixing itself.

Will now attempt to clean the Throttle Body, related parts, and very carefully inspect the vacuum lines. (could it be the Throttle Position sensor??).
Any helpful comments welcomed!