I've read lots of the mystery misfire and stutter threads but none are quite like the one I am having so I thought I would give the community a look at it: This '03 Econoline starts, idles, runs like a dream around town all day everyday but when you make that turn out of town and accelerate it hiccups ack.ack.ack like short sharp misfires, then around 45mph under load it does it again real consistently and bigger gaps in power until you get into higher rpms or punch the accelerator past 45 quickly. Appears again around 60mph, often it comes on hills as the engine comes under increased load. It seems you can avoid it by accelerating very slowly up to 70mph as long as the road is flat. Once had to limp through mountains using second gear at 45-50mph and that kept it from shudder/shake/cough/ack! If you don't try to address it the shudder will turn to heavy shaking throughout but I couldn't say; drivetrain or engine or where it's really coming from, global I guess.

What I've done NEW: alternator, air filter, coils, plugs, injectors, all wiring (yes, all wiring outside the van cabin), PCM, CATs, HO2S, fuel pump, fuel lines, fuel rail, cleaned the MAF, thottle body & IAC. Not getting any codes (before or after work) with cheap scanner. Most of this work has been done as reconditioning rather than to address this symptom. I have about $300 worth of sensors that I was thinking of putting in this van (want a travel/camper van for retirement and want it to be reliable with known parts and keep some of the existing as spares for an emergency if I get into the 'outback'). Was hoping the stutter would be addressed after my reconditioning but it is exactly the same as it was before work began. I have seen some references to 'reflashing the PCM' and the 'Trans fixes itself' in regard to the stutter but don't know what that is really about, also I put the original COPs into another vehicle to test and that truck is running fine 3 months later (it had a set of OEM COPs installed just before I swapped them out and I have tested a couple of those in easy to reach positions just to see if any info could be learned). The originals were mix of aftermarket and mostly OEM, the replacements are OEM Motorcraft and the spares are now OEM Motorcrafts.

 

I have a simular issue with my truck, I've heard it can be the torque converter, as soon as the converter clutch locks, shudder starts. Goes away at higher engine rpms.

 

Everything you have said is related to a bad COP or plug. What brand of coils and plugs did you use? Your only options would be motorcraft or denso for the coils and motorcraft for the plugs. Anything else and you will get the high load misfire.

 

I got a set of the Motorcraft COPs but everything I had read said plugs do not cause this, but I will order a set of Motorcraft plugs asap. With how many parts were changed in the van I thought there must be something that causes this that I am missing; maybe its the plugs? the old ones were originals that looked good but like I said I wanted to go to all known good as much as possible.

Probably covered elsewhere but are these: Motorcraft SP-479 AGSF22WM the correct plugs? Rockauto says yes and Amazon says no.

 

A misfire exists at all RPM's. If you do have a misfire due plugs or COP's then its there constantly--it doesn't come and go with RPM changes. The MIL would come on, a code reader would show a failed spark plug circuit. It won't hurt to change plugs to the specified SP-479's but this isn't the cause of your issue.

If the TC is suspected then post a shorter version of your description in the Transmission sub-forum---there will be tests or possible DTC's that can be retrieved to show or suggest whether this is indeed a transmission problem.

 

Nope. The engines tend to exhibit mild misfires under specific loading conditions. Usually, the loading is the worst just after it shifts into O/D during mild acceleration at around 45 mph. Unfortunately, the transmissions are also prone to exhibiting torque converter shudder under the same driving conditions. The conditions are difficult to distinguish without the proper diagnostic procedure.

The PCM will NOT post a fault code unless the severity of the misfire exceeds the calibrated limits for a fault. Such misfires are easily felt long before the PCM squawks a fault. Monitoring the live misfire data in Mode $06 is the best way I know of to see if it's a misfire or not.

In the event that diagnostics indicate it's TC shudder (no evidence of misfires in Mode $06), a fluid exchange with fresh Mervon V usually resolves the problem.

 

Thanks ppl. I think getting a scanner that can report/record live data is in order. Good meeting! hehe

When I got this van the trans fluid had been done recently and I only checked the level, but it has a drain plug in the pan so who knows if they ever did a filter or what fluid was used, it's another good chance to get that into the 'known good' dept. sounds like I should wait though until the scanner gives me some data before I retire all that ATF.

 

It could be torque converter shutter. If the fluid looks good, add some Dr Tranny Instant Shudder Fix. If it can be stopped, that will do it. My 4R70W was shuddering so bad I knew it had to be coil packs. After chasing it for several weeks, I went to a trusted transmission shop. They hooked their computer up and drove the car. It showed no misfires, but did show torque converter slippage under certain conditions. A complete fluid change and some Dr Tranny fixed it up. That was several years and quite a few miles ago, with no more shudders.

Also, check the DPFE sensor. They tend to corrode inside and stop up, causing weird EGR valve operation that can feel like a mis-fire and shudder. They are not that expensive, and if you have much over 100k miles, it's not a bad idea to change it anyway.

 

The modular is known to have misfire under load only. Its only once under load and the PCM changes the AFR does the misfire begin. Common areas for voltage leaks are at the COP boot or the plug insulator can crack ( huge reason not to side load a plug when testing it). Its a prevalent enough issue that it shows up as a service procedure before transmission diagnostics. The CEL also will not illuminate but will flash and that flashing is indicative of catalyst destruction.

 

Thanks ya'll for participating, I have to recognize that this IS similar to other threads that have discussed this, didn't mean to ignore all advice that has been established and ask the same question! Scanner might even show up tomorrow so I will report back with findings...

Dr. Tranny looks like a Seafoam, Marvel Mystery Oil type product, never tried one but I am bookmarking it for sure, is there a 'tear it down' fix also? (assuming we don't find any misfires and fluid change/additive doesn't help) or just replacement of the TC?

 

No need to jump off that bridge until you have more information that is useful.

 

Thanks for that bit of education---great info from two knowledgeable members here!

 

DELAY: Got a scanner (OBDLink MX+) and had 1 somewhat successful test drive but did not know how to setup capture live data so upon returning there was no 'misfires' data. All the basics were reporting; speed, rpm, engine temp, MAF% but no log or report. There was one category (we are using OBDLink iOS software on Ipad) that mentioned misfires and had a green check for enabled and a green check for reporting if memory serves but there was no data stored for the test drive near as I could tell. Then after doing a bit of research (scan tool comes with no manual and no online manual!) found some settings to look at in the software but of course the unit would not connect again after that first success! argh. Tried another device (Iphone) with the OBDLink software installed and same result; unable to connect. Tried another iOS scan app as well which could not connect. Also seems the devices are now failing to connect! Each time we have tried to do it by the book (quick start guide) and also did a few 'factory resets' with no success. I might try a laptop next running the Windows version of their software but with no phone support or web support (left a message on a forum they link to on odblink website) I am getting nowhere... ugh. if laptop is able to connect I will report back.

 

More mystery and I cannot get this scan tool (when it connects) to record a data stream never mind any misfire data. Been going back and forth between vehicles to test if this scan tool is working. when it has worked the vehicle is just parked, running and just key on. but it has not been connecting to the the van that I want to work on! argh. I tried it on a Ford Windstar and it would connect just about without issue and stayed connected but the E350 still barely connects and doesn't stay connected. Still working on doing a successful data stream capture, probably should get that worked out on the Windstar and then try to reproduce in the E350. Still learning...

 

Scan tool gave up some info in Mode $06 tonight, yeah! Reported: CID $00 TID $50 $55 and $56 all failing with 8x, 3x and ($56) 10x over the maximum. Problem here is I do not know what Component ID $00 refers to, I am guessing something like 'total events' but within that data I can see one value TID $55 is the same as CID $02 TID $53 (they both failed with over 3x maximum allowed with the exact same number). There are CID reports for $00 - $08 so I was guessing that the 01-08 were cylinders. On the upside CID $01, $03, $04, $05, $06, $07 & $08 all reported (0) of what I am guessing represents misfires...

Anyone used this data before? Do you know of a chart that lists corresponding components for Ford Mode $06 IDs?

ALSO: Would one cylinder misfiring a lot cause the van to shudder quite strongly?

thanks!