Bucking & missing revisited; '99 LX 3.8L

Windywoes · #1 10-22-2009, 12:57 PM

You may recall that I was getting a missing/bucking issue when loading the van up a hill at low RPM's and 3rd or 4th gear. Replaced DPFE sensor, new plug wires, 30K on plugs. No change.

Today I finally checked the coil pack electrically and all seems in order. I also took off the EGR valve to check for blockages. None. I removed the upper plenum since it had been a month since my last inspection and I was shocked to see large pools of oil again. After cleaning it all up this time I installed a small coalescing filter in-line with the PCV-to-throttle body hose. Hope that will pull the oil out of the flow.

Question: Is it possible that when I go up a hill that the pools of oil could seep down into the lower plenum and is then ingested in the fuel/air stream?

Another question: What function do the IMRC's serve?

12Ounce · #2 10-22-2009, 01:22 PM

Quote:

Originally Posted by Windywoes

Today I finally checked the coil pack electrically and all seems in order. But it probably is not all in order ... if you are getting no CEL, I suggest a new coil pack.

I also took off the EGR valve to check for blockages. None. I removed the upper plenum since it had been a month since my last inspection and I was shocked to see large pools of oil again. So what's the problem with pools of oil??

After cleaning it all up this time I installed a small coalescing filter in-line with the PCV-to-throttle body hose. Hope that will pull the oil out of the flow.Bad move! You should not do anything to hamper the EGR flow ... its designed to do a certain precise task!

Question: Is it possible that when I go up a hill that the pools of oil could seep down into the lower plenum and is then ingested in the fuel/air stream?Yeah ... and that's OK! Unfortunately, it also drips onto the EGR jets.

Another question: What function do the IMRC's serve? It has to do with keeping the air velocity high enough for good mixing at the injector tips. When the engine is running slowly, the velocity is increased by shutting off one of the passages. This all goes away when engines are upgraded to "direct" injection.

Good luck!

Windywoes · #3 10-22-2009, 01:53 PM

You'll have to do more to convince me about replacing the coil pack. Why do you think I need to replace it?

Pools of oil sitting proximate to air/fuel mix flow? My inlet ports are dark brown and all coated with the junk. At least the combustion chamber is getting good lubrication-whether it needs it or not.

Why do you think a coalescing filter inhibits the flow?

Thanks for the primer on the IMRC's. Now I get it.

northern piper · #4 10-22-2009, 02:44 PM

I'd say mainly because as the filter becomes more clogged it'll slow air flow. I'd suggest a "catch can" inline with the PCV valve lines as a better option. On mine I get a fair amount of oily gunk especially in cooler weather.

Windywoes · #5 10-22-2009, 06:11 PM

I had intended to see what the catch rate was like and then maybe take the sintered element out and just use the bowl. We will see how it all works. After cleaning up all the oil in the lower plenum I can't get the van to buck or miss as it always has recently. We took Windy to VT over the weekend and she bucked like a Mustang (no car pun intended) going up all those hills and mountains.

Waxhaw · #6 10-26-2009, 12:08 PM

I agree with 12Ounce about replacing the coil. My 2001 Windstar started missing/bucking last year under load - slight accereration in 3rd or 4th, sometimes starting out in 1st. I had a missfire code on one one cylinder then I noticed when it would buck under load the cel light would flash. Took the coil out and it had some cracks in the bottom and in the black sides. It ohmed good. Don't remember the figures but all three primaries and secondaries were consistant. Cleaned it with soap and water, dried it good and it ran fine for two days, about 50 miles. Ordered a new coil on e-bay and installed it, it's been good ever since. You can search for other folks posts on coil problems. If a new coil doesn't fix it keep the old one for a spare, you'll need it sometime! Cheers,

Windywoes · #7 10-27-2009, 02:15 PM

Hi Waxhaw. Sure do appreciate your inputs on the coil. After cleaning all the oil out of the manifold and adding the catch can for oil vapor it ran fine for almost 4 days and now it is bucking again. I think I can't put off replacing the coil even though it metered out OK and I could not see any cracks (doesn't mean that there weren't any).

Was the eBay unit new or used?

Waxhaw · #8 10-28-2009, 08:40 AM

The coil pack was new Windywoes. I would hesitate buying used unless really looking it over for cracks as mine ohmed good but broke down under load. The new coil was advertised as the same part number I took off, 1F2U-12029-AC, but when received it was a little different number. The basic 12029 was the same. I'll look the part number up tonight and post here as it has worked great. Ohmed per book figures, was Motorcraft and looked exactly the same. The seller said it was a new "take off" from a different application.
Cost with shipping was $40. about half regular price. I don't know if aftermarket brands last longer or not, maybe other's have that expeirence. I think all the parts stores have coil packs to replace Motorcraft.

12Ounce · #9 10-28-2009, 09:59 AM

My last engine "stumbling" issue was cured by a new coil pack. The event was so rare it would not light-up the CEL. I tried inducing a known EGR code, and then after the CEL lit up ... I went for a scan at AutoZone, there was the expected EGR code plus a misfire code. After eliminating plugs and wires by switching things about ... the misfire code remained unchanged. That left little other than the coil pack. Can't remember if I used aftermarket or not.

Windywoes · #10 10-28-2009, 05:59 PM

Good comments, 12Ounce & Waxhaw. If I can get a $40 coil I will definitely replace it. Otherwise I have deferred it since work is slow.

Hey, ya know what? Come to think of it the problem is worse on rainy days. Does that further implicate the coil?

12Ounce · #11 10-28-2009, 07:29 PM

Kinda.

Waxhaw · #12 10-30-2009, 09:24 AM

Windywoes, here is a post from 2-14-09 of mine that has the coil part numbers, I haven't had the bucking/popping since installing the new coil eight months ago:

Re: Bad coil pack symptoms
Thanks for the above Grabber. I bought this 2001 Windstar in Dec and it had new plugs and leads 2k miles before. From this forum I pulled a front plug and it reads "Autolite XP-105 extreme performance." Looked like a dab of platium under the outside electrode so I think they are double platium. The gap was .044" which is spec from Autolite. The Workshop Manual says .052 - .056" but I may not be in a hurry to remove them all to regap. Thanks too to all the others posters as all have helped me figure out my problem! I've read a ton of stuff here.

The van started popping backfires again about 30 miles after cleaning the cracked coil.

Received the new coil from e-bay Weds. My old cracked one was a Motorcraft 1F2U-12029-AC. I thought the new one from e-bay would be that or a 1F2Z-12029-AC or DG485 as advertised. Nope, it is a new Motorcraft 5F2E-12029-AA. The Ford factory Workshop Manual calls for a 12029, without a prefix or subfix. So, maybe they are all interchangeable, looks exactly the same. The new 5F2E-12029-AA ohms at: primaries .7 and secondaires 10.32k - 10.54k ohms, just like my old one.

Anyway, I installed the coil and it works great. No more back/crossfiring popping, no more chugging a little in upshifts or overdrive when lightly accellerating. I have driven about twelve trips of 6-20 miles with no problems. I am happy with my $40 coil.

Oh, for the what it's worth department, I stuck my old cracked coil on a pan in the oven after the very understanding wife had baked supper. The oven was 300 degrees and turned off. We ate supper while the coil heated as the oven cooled. I tested it after about 30 minuites when the secondary posts checked at 160 degrees F. The primaires went from .7 to .8 ohms and the secondaires went from around 10.4k ohms to around 13.3k Ohms.
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Windywoes · #13 11-02-2009, 02:53 PM

Thanks Waxhaw. I ordered a F52Z-120290-A from Amazon for $54 plus S&H. Hope this does this trick for my bucking problem. I will let you know after part arrival and installation.

tbrace · #14 11-07-2009, 05:44 PM

do you have to buy the coil from amazon or ebay?

can you get it at napa, auto zone, advanced auto etc?

thanks

wiswind · #15 11-07-2009, 06:29 PM

You can buy the coil pack at most local auto part stores or the dealership.
Folks are buying it on Ebay or Amazon in order to save money.
As always, check the price at the auto part store / dealership (you can do this online) before you shop ebay or Amazon so you will know the retail price....and know if you are truely saving any money.

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