Help me pin point this rought idle...!

[69cuda340s]

If you did have carbon tracking and arcing around the plugs and then changed the wires without changing the plugs the current can travel the carbon track along the plug and still cause a miss. I know its a long shot but it does happen. To make sure you don't have any arcing on the wires/plugs/coil run the engine with the cowl off in a very dark area and see if you see any arcing. If you don't then you can rule that out.

[Ed_Strong]

Just came back from working outside. I got the Belt Idler replaced, gave me a hard time but no biggie.
When I bought the Belt Idler, I took the battery to the Auto Parts store and had it tested. I was able to pass the first test (load test I guess) then the guy asked me if I wanted him to charge the battery, I said sure why not.
He put it to charge and 45 mins later came back to tell me the battery would not hold a charge. I brought it home put the voltmeter on it and it showed 12.54 volts... what gives?
Anyway, I went and got a new battery and replaced the old one. The van started right up and gave me no issues cranking.
But it still giving me the rough idle, and the fuel smell feels even stronger at the tailpipe. It was pretty dark outside and I look for arcing but didn't see any arcing or sparks flying (other than my brain frying). The plugs were replaced @10K miles ago with AutoLite's Double Plats by the way.

I went to take it for a ride and it started backfiring right away.

On my first post I covered what I've done before coming here for help... Air/Fuel filters, MAF cleaned, Berryman B12 in the tank, cleaned IAC/TPS sensors, etc.

[wiswind]

The EGR behavior puzzels me....but I would expect that it would light the CEL.
Clogged EGR ports, DPFE, etc.....all should light the CEL if it was causing this extensive of a problem.
I hate to keep telling you to change this part and that.......as that adds up.
I revisited the tune-up items....as you would hate to go to a shop, just to find out that it was a simple tune-up item.
I have the AutoLite double plats in mine right now.....and they are doing just fine.

[96wWindstar180K]

Ed_Strong
The backfiring sounds like a timing issue as the timing is controlled by the pcm that confuses things more. However as Wiswin said that a fuel delivery problem could be an issue as Im well aware of. I had kept checking my fuel pressure (purchased a fuel pressure gauge from Sears for $30.00) There seemed to be no problems. However I realized by leaving the gauge on as driving (cowl off taped guage to the windshield I could watch the pressure change. The biggest note was at cranking. When you first turn the key on you hear the fuel pump run for a second or 2. I thought that was good. When I applied the gauge the fuel pressure was 20 Llbs. If I turned the key off and then back on the fuel pump would run again and the pressure would go to 30lbs. The fuel pressure should remain about 40lbs with the key on engine off and maintain that pressure give or take. If you notice change at the given rpm of the backfire I would suspect the fuel pump or fuel regulator. My problem was similar in that I figured if the fuel pump was bad it would starve at higher rpm. Not so. I you cant figure it out in my opinion I would take it to a shop and have them diagnose it. It cost me $108. to put in on the computer and tell me exactley what was wrong. I had them do the fuel pump but i replaced all the fuel injectors as one was bad and I had so many miles. I kept throwing money at it replacing parts and could have had it diagnosed for much less. The only reason I didnt feel to bad is the age of the van and miles. Replace it now or replace it later. Preventative repairs

[Ed_Strong]

Today I went to start the van and it cranked slow again after 2 days with the new battery. Could this be related to the problem?

I had a suspision that something could be draining the old battery and I checked at night for anything that might be staying on and there are no lights staying on inside or outside, or anything making sounds.

Anyone have any clues...?

[tripletdaddy]

Just about anything can cause a silent drain. If you think your battery prematurely needed to be replaced, I'd be suspicious of the alternator. Make sure everything is turned off. Disconnect your battery pos cable. Try tapping it on the battery post to see if it sparks any. Big sparks for big draws, little for little. If it is big, you can't use a normal multimeter to test the current draw. You will have to use a clamp meter or the voltage setting on your multimeter. Put your multi meter between the battery and the cable to measure current draw or voltage(current is better). Start pulling fuses to see if a major change occurrs, drop. Check the fuses underhood if no luck with inside fuses. To check the alternator, pull all the connectors off of it and see what the meter does. You might do that first, then the underhood, then the inside fuses last. I wouldn't expect much more than 0.05 amps draw normally with it off as there is the computer, radio, alarm, remote entry etc, that draw current even with the van off.

[northern piper]

a little while ago on this board someone was complaining of a mystery battery drain and it was traced to a bad rear windshield wiper. Seemed that it was the intermittant part that caused the problem. Just an "off the top of my head" thing.

Piper

[busboy4]

Hi
I had posted earlier on another thread about the rear wiper. A friend with a 2000 has now had the problem twice - mystery battery drain. In both cases on closer inspection the rear wiper was out of place, both times too low on the window partially onto the body. Apparently, the system continues to try and "park" the wiper. I don't know why it does not blow a fuse, nor why a GEM does not shut off the power after a period of time (like it would a dome light). But in any case, twice dealing with the rear wiper corrected the problem.

Good Luck

[CnlK]

While it may not explain the original rough idle condition, from your posts it
sounds like the backfire/fuel smell issue started after replacement of the ignition coil and plug wires. You mentioned that you replaced only one wire at a time but it sounds like a wire might have been crossed. Was the layout of the coil the same? Or if the rear plug wires were replaced somewhat blind by feel maybe the boot end was inserted over an exhaust manifold stud. Misfiring would allow unburned fuel into the exhaust. To check your alternator for a draw, with engine off, remove the heavy red output wire and install an ammmeter in series, I had one that had a 4.5amp draw. Just another thought, maybe the rough idle and now backfiring are the result of a broken intake valve spring.

[Ed_Strong]

I must admit, the rough idle started when the coil & wire set were replaced, but... the engine will not backfire or run worse than before while in nuetral. It runs worse and backfires while in gear and backfires when you give it gas while driving, once you lift off the gas it stops backfiring.
Im thinking of putting the old coil back on it tomorrow and see if it stops backfiring.

Today I managed to get a Snap-On OBDII diagnostic machine to test and at the KOEO Self Diag Test it didn't find anything wrong. The I ran the KOER Self Diag Test and it came out with.

P1000 OBDII System Checks Incomplete
P1127 HO2S Downstream Sensor Not Tested

I checked all the sensors readings and everything seemed fine. Then ran the KOER Self Test Diag again and it posted:

P1000 OBDII System Checks Incomplete
P1127 HO2S Downstream Sensor Not Tested
P1151 HO2S21 Snsr Indicates Lean

Not sure about this results but I would really like to fix it my self if you guys could help me!

[tomj76]

It might be time to go back to basics, meaning ye ol' timing light and vacuum gage. You can tell a lot from these tests. If the backfire is coming from timing or a mechanical problem, or a vacuum leak, you'll see it with these checks.

[Ed_Strong]

Pulled the old timming light out and checked the front three plug wires and they all have electricity flowing. Couldn't check the back three because of clearance and fear of getting burned, but I'm sure they also have power flowing. Still smells like raw fuel in the engine bay and out the tail pipe.

I'm gonna throw the old coil back on it and see if the backfiring goes away. With the cowl removed I'll check the back plug wires with the timming light and I'll remove the plugs to see if they're flooded.

Out of curiosity I disconnected the alternator and cranked it up to see if there was any difference to no avail... I left it unplugged overnight to see if the battery drains again while it sits thru the night.

I really cannot see, hear or feel any vacuum leaks! Now, what kind of connections do we have on the lower back of the engine? Like below the plugs if there's any?
I smell a hint of burning rubber or plastic and wonder if there's a loose wire making contact with the manifold or converters, but can't see anything back there.

[CnlK]

Interesting that one of the O2 sensors was throwing a lean code. Possible that sensor is bad stuck on lean, the PCM trying to compensate could be making the engine run in an overly rich condition, thus the fuel smell. Other senario could be that it is actually running lean and not burning fuel. I don't know how one would actually test the timing on the 2000 3.8l without use of a mirror or making your own timing marks. A professional scan tool can be used to check ign timing, even that would give false results if the harmonic balancer/trigger wheel on crank had rotated out of proper position due to a sheared key.

[12Ounce]

I have noticed that none of the aftermarket coils (that I have used) had the diagram on top that shows which coil section fires which plug/cyl pair. In fact, one of the aftermarkets (AdvanceAuto) replacement had a whole different order of coil-sctions ... not the same as the original ... was very tough to fiqure out. The Ford replacement has the drawing glued in place and, of course, has the same original coil-section order.

(Edited, ... thanks, Ed): IIRC, the rear-most section (closest to firewall) fires the 1&5 pair, the center section the 2&6 pair, and the front section the 3&4 pair.

[Ed_Strong]

Originally Posted by 12Ounce

I have noticed that none of the aftermarket coils (that I have used) had the diagram on top that shows which coil section fires which plug/cyl pair. In fact, one of the aftermarkets (AdvanceAuto) replacement had a whole different order of coil-sctions ... not the same as the original ... was very tough to fiqure out. The Ford replacement has the drawing glued in place and, of course, has the same original coil-section order.

IIRC, the rear-most section (closest to firewall) fires the 1&4 pair, the center section the 2&6 pair, and the front section the 3&5 pair.

You're right 12Ounce... the aftermarket coil (AdvanceAuto) don't have the diagram on top that shows which coil section fires which plug/cyl pair.
What I had to do was draw the engine on a piece of paper with the firing order and then copy my own diagram from the top of the original Motorcraft coil on the same paper.
For reference the actual 3.8L firing order on the coil is the rear-most section (closest to firewall) fires the 5&1 pair, the center section the 6&2 pair, and the front section the 4&3 pair.
Looking at it from the top will look like this...

rear (closest to firewall)

|5&1|
|.....|
|6&2""|
|.....|
|4&3|

front (closest to TB)