miss/stutter....thoughts??

[Thomas C Potter]

92K miles, original spark plugs etc. Mostly does it in 4th gear, low rpm, moderate acceleration. Light accel ok. No check engine light.

I do not have a hand held code device...yet

Thoughts??

Blue 2003B


AND, a couple of times the red brake light stayed on for a few seconds. This occurred occasionally, a few days after some ABS activation back when we had some snow.

[Ken]

11 years, 92k...

Plugs and COPs?

[whitey]

COP's most definitely, and might as well change the plugs while youre there.

[RichardP]

COPs definitely.. happened on my car

[lifespeed]

You ran those spark plugs a good 40K miles too long. COPS are also a possibility. Knowing what I know now, having wasted quite a bit of time troubleshooting rough running and misfire, I would replace both the plugs and coils. Unfortunately the original COPS had some early failure issues, but their replacements seem to be pretty good.

And replace your O2 sensors also. These are all regular maintenance items, and often a pretty noticeable improvement when your stuff is old.

[MOTOWN]

Replace your spark plugs first, your coils may be fine, dont throw money at parts unless you are certain they are in need of replacement.

[lifespeed]

Replace your spark plugs first, your coils may be fine, dont throw money at parts unless you are certain they are in need of replacement.

Good advice, but the COPS are well known for failure.

[MOTOWN]

Good advice, but the COPS are well known for failure.

That may be the case, but as i stated just confirm they are indeed bad before spending cash that may not be needed. mines have 107K on em and still going strong!

[MERCULES]

When you say COPS do you mean coil pack or something to do with electronic coils? Sorry but I have only had my marauder a few weeks and I am on the learning curve.

[Marauderjack]

Sticking EGR valve can give a slight surge feeling under light to moderate acceleration at around 45 MPH with the TC locked!!:mad2::argue:

I replaced the EGR valve and it was GONE!!:beer:

I still have my Original Coils with solid connectors......253,000 miles and almost 170,000 miles with the blower!!:cool4: Guess I've been lucky!!;)

[MOTOWN]

When you say COPS do you mean coil pack or something to do with electronic coils? Sorry but I have only had my marauder a few weeks and I am on the learning curve.

Yes COPs are coil on plug which is what our cars have

[fastblackmerc]

I replace my plugs every 2 years regardless of the mileage. Cheap insurance.

[RF Overlord]

I do not have a hand held code device
Most FLAPS will read codes for free. Pending codes will not set the CEL, so it's worth a shot.

FWIW, Mary's car once had an intermittent miss that turned out to be a bad COP on #3...didn't set a CEL.

[GreekGod]

Yes COPs are coil on plug which is what our cars have

You have eight ignition coils, that are installed above the spark plugs, and connected by a spiral wound spring to the "plugs" ... ergo the COP reference = Coil On Plug

==============

[Thomas C Potter]

THNX GUYS. To change the 02 sensor, disconnect battery??? yea, I could look in the manual, but this is easier....

[fastblackmerc]

THNX GUYS. To change the 02 sensor, disconnect battery??? yea, I could look in the manual, but this is easier....

No.... I'd suggest using Ford sensors... they will last the longest.

[whitey]

Did i miss something? Where did o2's come into play?

[fastblackmerc]

Did i miss something? Where did o2's come into play?

Post #15...............

[whitey]

Post #15...............

Right, but whats that have to do with cops? :lol:

[lifespeed]

THNX GUYS. To change the 02 sensor, disconnect battery??? yea, I could look in the manual, but this is easier....

Yes, and there are four.

[lifespeed]

Right, but whats that have to do with cops? :lol:

Rough running, regular scheduled maintenance. Any car with 100K should have the O2 sensors replaced. Stand by for "I've got 200K with the original O2 sensors and she runs FINE".

[whitey]

Rough running, regular scheduled maintenance. Any car with 100K should have the O2 sensors replaced. Stand by for "I've got 200K with the original O2 sensors and she runs FINE".

160k here so far:P

[lifespeed]

160k here so far:P

Let me know how great it was running on the old sensors, after you put a new set in.

[GreekGod]

Let me know how great it was running on the old sensors, after you put a new set in.

I understand how the O2 sensors could possibly affect throttle response, mid-range, and idle, but wouldn't full throttle be un-affected?

=====

[lifespeed]

I understand how the O2 sensors could possibly affect throttle response, mid-range, and idle, but wouldn't full throttle be un-affected?

Right, O2 aren't used at full throttle. I just mentioned it as it seems to be an often-overlooked maintenance item and I noticed quite an improvement in throttle response, drivability and fuel economy when I replaced mine.

[whitey]

Im not saying they are running in tip top shape, but what i am saying is to please explain to my wife why i need to replace them if the cars running fine:D. Ive been around 21mpg, summer gas, since ~86k when i bought the car. Some things i replace ahead of time, like my new 180° thermostat, other things im not fixing until its broke.

[GreekGod]

Im not saying they are running in tip top shape, but what i am saying is to please explain to my wife why i need to replace them if the cars running fine:D. Ive been around 21mpg, summer gas, since ~86k when i bought the car. Some things i replace ahead of time, like my new 180° thermostat, other things im not fixing until its broke.

You don't need to replace them! ... I check every tank for mpg -- and I'm over 85K miles. It is total BS to change O2 sensors as a maintenance item!

==========

[whitey]

You don't need to replace them! ... I check every tank for mpg -- and I'm over 85K miles. It is total BS to change O2 sensors as a maintenance item!

==========

Thats where im getting at, if im not throwing codes, im still in range, and until my cel tells me different, they'll stay in.

[lifespeed]

Modern O2 sensors are generally thought to last about 100K, on average. Obviously this varies. They can get fouled out much earlier if there are engine problems, or probably last longer under ideal conditions.

It is a common myth that the CEL will come on to warn you of a failure. Generally not true, a slow or "lazy" sensor won't trigger a CEL, only a complete failure will. O2 sensors can be checked for switching speed with the proper tool. I did so on my old '97 CV at 140K miles and realized it did have a lazy sensor.

I noticed some roughness at idle and part throttle response didn't seem what it once was. This was at about 108K miles. I replaced the O2 sensors and the engine immediately smoothed out and become more responsive. So what conclusion would you draw given the available information and before/after results?

As to convincing the wife, can't help you with that.

[whitey]

My idle is between 795-805, my car is still responsive enough by my standards. Just because you had an unfortunate o2 failure, doesn't mean it's going to happen to everyone. I had my tranny go out at 107K, doesn't mean everyone elses will. I still have 28 spline axles, and im not suffering the soft axle problem(#206 of the assembly line). My paint still looks good, even though were notorious for bad paint. If im not seeing a cel, im not changing the o2's...theyre still in range. In no way am i saying your issue was bogus, but it doesn't pertain to my car.....yet.

[Mike D Mechanic]

had same prob worst in traffic aprox 35-40 mph , plugs first then new set of coils changed fuel filter with 6k on it. it was the filter ! had checked fuel pressure early on with my programmer in real time psi looked good . so when to spark issue. funny part I am now getting the mpg I have ever got :)

[Thomas C Potter]

new autolite plugs solved, but will do ox sensor soon.

Thnx all.

Blue in VA

[grandepau00]

new autolite plugs solved, but will do ox sensor soon.

Thnx all.

Blue in VA

Had the same problem about two weeks ago. Slight miss/stutter under light throttle and no CEL. I replaced all the coils with motorcraft coils from ford racing and all of the spark plugs with motorcraft plugs (part# sp-430 I believe). When replacing the plugs I noticed the previous owner installed autolite plugs. I believe this is what caused the misfire in the first place. Just my $0.02

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[whitey]

Had the same problem about two weeks ago. Slight miss/stutter under light throttle and no CEL. I replaced all the coils with motorcraft coils from ford racing and all of the spark plugs with motorcraft plugs (part# sp-430 I believe). When replacing the plugs I noticed the previous owner installed autolite plugs. I believe this is what caused the misfire in the first place. Just my $0.02

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Autolight ap 104s are good plugs, it was the coils.

[grandepau00]

Autolight ap 104s are good plugs, it was the coils.

I just get nervous with plugs. Japanese cars I only use NGK, German Bosch, GM's AC Delco...etc.

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