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View Full Version : Cutting out under acceleration - I'm stumped



tomhilmes
08-29-2012, 09:01 PM
I don't post often. Most times when I have an issue with my car, I search these forums and find the exact answer. I've repaired my climate control, replaced my LCM, dealt with air bag issues, etc etc all based on what gets shared here.

You guys are awesome.

But I've got one that I can't seem to find a result for:

The car (2004, 106k, bought new, bone cold stock) is studdering/shuddering/cutting out or something at given rpm/speed ranges.

First noticed it on the highway with family in car. When headed up hill (in OD) at 1,600 - 1,800 rpm's it was acting like a pretty bad miss. Pulled out of OD and did same thing. Tach appeared to be rock-steady during the events.

Back in town, does same thing around 1,100 rpm rolling about 35-38 mph. From a steady pace, slight acceleration will cause the symptom. Also a change in grade with induce it. Does it at same rpm range in OD, D, and 2.

Changed plugs (looked good but were ready) and had trans fluid replaced (did the in-line fluid replacement machine process). Plugs lessened the issue immediately. Do not like the way the coils plug onto top of plug. I was looking for the satisfying click doesn't look like they are made that way.

Fluid change did improve overall transmission feel (think it went 30k since last change) but can't say it improved anything.

Did discover next (now alone in the car) that full on pull from 60 - 90 yields what feels like a slight, inconsistent miss.

I'm thinking ignition or spark or some obscure sensor somewhere. Hoping and feeling the transmission is good. My next steps (since it needs to be done anyway) are to change the PCV and fuel filter.

Looking for the simple stuff. Ideas anyone?

Thanks, Tom

Jolly Roger
08-30-2012, 01:03 AM
I'm thinking fuel filter.

MMBLUE
08-30-2012, 02:14 AM
COPS :confused: Do a seafoam treatment, PCV, and injector cleaner.

babbage
08-30-2012, 05:51 AM
This is a classic symptom of a bad DPFE (bucking at float or low throttle input in a high gear) DPFE is integrated with the EGR. Sooo: get a new EGR installed.

Next on the list for you (100K+) would be a new fuel pump and screen.

Post back if it was the DPFE in the EGR.

Gordy
08-30-2012, 06:11 AM
If none of those fix the problem, and it only does it and low rpms and goes away if you "hammer down" full throttle, you might have a coil going bad. If its just going bad and has not gone out completely, the car will never throw a code "drove me insane." I just went ahead and replaced them all but its almost always on fords cylinder 8's coil (don't ask me why) lol. If you recently washed the engine bay its very easy for water to get under the coil cover and that will cause it too.

Krytin
08-30-2012, 07:34 AM
This is a classic symptom of a bad DPFE (bucking at float or low throttle input in a high gear) DPFE is integrated with the EGR. Sooo: get a new EGR installed.

Next on the list for you (100K+) would be a new fuel pump and screen.

Post back if it was the DPFE in the EGR.


+1 on this!

Ozark Marauder
08-30-2012, 02:20 PM
Mine did the same....was a bad COP...

OZ

RacerX
08-30-2012, 04:48 PM
It does sound like a bad COP. Like you said, try cheaper options first (egr as Eric said), but, recently having found bad coils, especially after the engine was heat soaked, I vote bad coil.

maineiac
08-30-2012, 06:16 PM
I am having same problenm since NH,cop's arrived today installing in morning,i will update status.

1stMerc
08-30-2012, 06:17 PM
If none of those fix the problem, and it only does it and low rpms and goes away if you "hammer down" full throttle, you might have a coil going bad. If its just going bad and has not gone out completely, the car will never throw a code "drove me insane." I just went ahead and replaced them all but its almost always on fords cylinder 8's coil (don't ask me why) lol. If you recently washed the engine bay its very easy for water to get under the coil cover and that will cause it too.

Yep, that's my vote. Wrestled with the same thing few years back, especially after getting under way after going over railroad tracks.

whitey
08-31-2012, 09:18 AM
Cop.....mine gave out around 93,000 miles , didnt figure it out for 5000 miles....did everythinf you did...change tranny fluid, fuel filter, and nothing helped.

mrjones
09-01-2012, 08:50 AM
Another vote for the COP. I just had this exact problem with my 04. It finally got bad enough to set a code for the miss so I knew which cylinder it was. I bought a Borg Warner replacement at OReillys for less than $40 and I was very happy with the fit and performance so far.

greggash
09-01-2012, 12:46 PM
Get a complete set of COPs
Accell on Summit around 200 for a set

do not replace just one, it is not worth it

tomhilmes
09-01-2012, 06:21 PM
Done the fuel filter so far. PCV appears to be fine. Going to investigate COPS next as most suggest. Accel kit is $275 on summit. Think the DPFE concept might have merit as well. Wish it would throw a code! Will report back.

babbage
09-07-2012, 01:32 PM
Done the fuel filter so far. PCV appears to be fine. Going to investigate COPS next as most suggest. Accel kit is $275 on summit. Think the DPFE concept might have merit as well. Wish it would throw a code! Will report back.

I and others on this site have had issues with the "less costly" accel cops.
MSD or OEM are best with the GMS rope plug wires.

I bet you its the DPFE.. ;)

Pat
09-07-2012, 04:27 PM
COPS, I had three bad ones. Don't get ones made in China. Replace them all.
I also had a bad DPFE, different time, but it threw a code.