Random bucking/jerking

[RF Overlord]

Been trying to track down an intermittent "hiccup" in Mary's car for a long time now. She was finally able to datalog about 7 minutes during which time the hiccup occurred. I don't have enough experience interpreting the graphs, so if there's someone out there with SCT LiveLink software who would be willing to look at the file and give me your opinion, I'd be mighty grateful.

TIA

[martyo]

Marty@mosspeedshop.com

[RF Overlord]

email sent...thanks, man!

[Mr. Man]

Could it be a bourbon issue :D

[martyo]

email sent...thanks, man!

Replied as well.

[1stMerc]

Bob, what kind of hiccup?

[MM03MOK]

It's like the engine stops for a second when I'm accelerating at around 40 mph when going uphill sometimes. Flipping off OD helps prevent it. It sputters. It doesn't do it consistently. On a couple of very quick accelerations from a stop, Phoebe backfired a couple of times.

[Mebot]

throttle body or possibly the COPs. you've cleaned the air box & MAF right?

sent from space

[RacerX]

Misfire. Possible bad coil. If the fuel/air charge doesn't ignite, it will usually fire off when it hits the catalytic converter. You can actually log each cylinder for misfires.

[1stMerc]

Yeah around 40 mph is when most people on here have ran into a bad cop. Usually straightens up once you get past that point. On mine it kicked in when resuming speed after slowing down going over railroad tracks and like you say going up hills.

[MM03MOK]

P0320 crank position sensor code has come up and replacing that sensor made no difference. Still throws the same code.

[justbob]

Is this the Trilogy car?


Self proclaimed Builder Of Badassery.

[MM03MOK]

Is this the Trilogy car?


Self proclaimed Builder Of Badassery.
No... SB....

[justbob]

That rules out the chip I thought you were still running.

My car had a faulty fuel pump and at least one bad COP at the same time for over a year and a half and drove me absolutely nuts to diagnose. Although it did not spit a code, the first six months left me with everything else you describe. After that, it only got worse.


Self proclaimed Builder Of Badassery.

[lifespeed]

My first thought when you described the symptoms was also COPs. Although the PCM can sometimes identify the misfire and throw a code, it is imperfect and should not be relied upon as infallible.

[RF Overlord]

To be clear, the car doesn't start to misfire, it's literally like someone turned the key off for a split second, then right back on again. One single jolt and it runs perfectly until the next "hiccup".

[burt ragio]

Code showing sensor after replaced condition continues. At apx 180,000 replace COP. You will smile from ear to ear.

[martyo]

BT did you get my email?

[MM03MOK]

BT did you get my email?

I told him about it today. Long and busy day yesterday. He didn't get on the 'puter.

[martyo]

I told him about it today. Long and busy day yesterday. He didn't get on the 'puter.

I am going to PM you Jeff's cell number. You/BT can call him that way as well.

[MM03MOK]

I am going to PM you Jeff's cell number. You/BT can call him that way as well.

Thank you, Dear!!

[martyo]

Thank you, Dear!!

You make me blush!

[RF Overlord]

I have the phone number. I hate bothering people first thing on a Monday morning, so I'll call him after lunch.

Thanks Marty... :up:

[pantheroc]

P0320 crank position sensor code has come up and replacing that sensor made no difference. Still throws the same code.

Mary, I had same symptom and crank sensor replaced back in 2002/3.

[martyo]

I have the phone number. I hate bothering people first thing on a Monday morning, so I'll call him after lunch.

Thanks Marty... :up:

Cool beans!!

[FF1077]

Im curious as to what the problem turns out to be.

I had a simliar problem last year.
http://www.mercurymarauder.net/forums/showthread.php?t=81360
But it was so bad to the point I couldnt even go up a hill. I relplaced the Crankshaft Position Sensor (CPS) and all was fine until a week ago. Getting on to the Freeway when my car did exactly what you described, like someone shut it off for a second. Did it again a few seconds later. Its done it a few time since then, usually around 55.
I pulled codes and got the CPS code again. I bought a new CPS, but im thinking the odds of having two bad sensors is pretty high..
Thanks.

[03sport007]

Im curious as to what the problem turns out to be.

I had a simliar problem last year.
http://www.mercurymarauder.net/forums/showthread.php?t=81360
But it was so bad to the point I couldnt even go up a hill. I relplaced the Crankshaft Position Sensor (CPS) and all was fine until a week ago. Getting on to the Freeway when my car did exactly what you described, like someone shut it off for a second. Did it again a few seconds later. Its done it a few time since then, usually around 55.
I pulled codes and got the CPS code again. I bought a new CPS, but im thinking the odds of having two bad sensors is pretty high..
Thanks.

Ah man!!! Not again!!!

[RF Overlord]

*UPDATE*

I wish I could say it's fixed, but no joy.

I got a chance to drive it myself and it only does it when accelerating, not while cruising. I am replacing the spark plugs tomorrow as it's time, but I don't think that's it.

It's like it only happens when the throttle is opened/vacuum drops. It even did it from a dead stop when I leaned on it more than "normal".

Does anyone think this could be a TPS issue? (No references to cover sheets, please :P )

[Mr. Man]

Just throwing this out there and have no idea how to check for it but it sounds like a momentary timing issue. As they all go 'Duh Eric". :o

Could it have anything to do with the FP sensor?

[justbob]

Testing the TPS is very easy with a multimeter. This link provides a lot of easy testing on various sensors to help guide you.
http://easyautodiagnostics.com/index_ford_4.6L_5.4L/index_of_articles_1.php


Self proclaimed Builder Of Badassery.

[RF Overlord]

Thanks, 'bob. I'm-a try that today.

[JohnE]

If the car is tuned properly, some things can be disconnected to test if they have gone bad. If it runs better without the sensor plugged in, good chance that sensor is related to the issue. The key is only one thing at a time. For instance, the TPS can be disconnected if the MAF and EGR (MAP Sensor part of it) are connected. Also you can disconnect the MAF, as long as you have the TPS and EGR (MAP sensor part of it). Try not to go open loop or WOT without the MAF if possible.


I can safely run my blower car hard without the MAF, because I took the time to tune the tables that predict things and I upgraded the MAP sensor to see boost. Most people with aftermarket tunes can not though. So don't go running a blower car without your MAF sensor, except for babying it.


John

[TooManyFords]

I can safely run my blower car hard without the MAF, because I took the time to tune the tables that predict things and I upgraded the MAP sensor to see boost. Most people with aftermarket tunes can not though. So don't go running a blower car without your MAF sensor, except for babying it.

Quoted for truth.

[mustang50lx]

If this is not fixed yet try to get access to an OBD II generic scanner. Look at the mode 6 misfire data. Bad COP's will show up under that data before they are bad enough to set a misfire code.

[martyo]

If this is not fixed yet try to get access to an OBD II generic scanner. Look at the mode 6 misfire data. Bad COP's will show up under that data before they are bad enough to set a misfire code.

This is very good advice, but I think it would be unlikely that COPs that are going down would cause what Bob has described as a momentary shut down of the car.

[Richy04]

My money is on a COP, under load they will pop and buck.. Every failure is different but usually predictable.

Check the harness where it comes around the drivers head.

Also check the ground strap on the back of the motor to the firewall. Mine went bad two months ago and high resistance caused all sorts of issues before it popped leaving me high and dry.. lol

[TooManyFords]

My guess is a faulty crank or cam trigger sensor.

[JohnE]

Rule out the cam sensor. The cam position sensor is only used at startup, to tell the difference between compression or exhaust stroke. If the cam position sensor is faulty, slightly longer startups are the possible result.

[RF Overlord]

OK, here's an update.

Yesterday, I changed the air filter, fuel filter and spark plugs, not because I thought they had anything to do with the problem, but because it was about time to do them anyway. Just now, Mary called me to say that she had driven the car about 30 minutes on both surface streets and the highway, and she suddenly realised that it was no longer doing it. She tried a number of different acceleration modes that previously would trigger the events and said everything was back to normal. :eek:

I can't believe the air or fuel filters could have been causing it, so that leaves the spark plugs. The ones I removed, Autolite 103s, had about 27,000 on them but they looked fine, other than being a little worn. I replaced them with NGK TR6s at Marty's recommendation. Could it really have been that simple all along? I'm gonna feel mighty stupid if that's what it was. Time will tell...

[burt ragio]

Bob good to hear you got the problem solved. Just for ***** & giggles cut open the gas filter.

[RF Overlord]

Don't know for sure that it's solved yet, but at least now if it comes back I've got it narrowed down to the COP harness, I think. It's the only electrical thing that was physically disturbed by the work I did.
Just for ***** & giggles cut open the gas filter.Fuel filter is already in the trash. I changed that, the air filter, and the transmission fluid on Saturday and took it for a ride. No difference. I did the plugs Sunday morning and didn't get a chance to drive it myself before Mary picked it up.

Crossing my fingers. :cloud9:

[SC Cheesehead]

Don't know for sure that it's solved yet, but at least now if it comes back I've got it narrowed down to the COP harness, I think. It's the only electrical thing that was physically disturbed by the work I did. Crossing my fingers. :cloud9:


My money's still riding on the muffler bearing...

[RF Overlord]

Reiten Sie auf dieser Dämmlager

[lji372]

My money's still riding on the muffler bearing...

that's usually the culprit:shake:

[WhatsUpDOHC]

Reiten Sie auf dieser Dämmlager
Is such formality necessary round hier?

[martyo]

I replaced them with NGK TR6s at Marty's recommendation. Could it really have been that simple all along? I'm gonna feel mighty stupid if that's what it was. Time will tell...

I am always happy to help make you feel stupid! :D

[SC Cheesehead]

I am always happy to help make you feel stupid! :D


Werd!

http://www.youtube.com/watch?feature=player_detailpag e&v=6MT3CihStFQ

;) -------------> :D

[RF Overlord]

:rolleyes:

With friends like you two........I should become a monk.

[SC Cheesehead]

:rolleyes:

With friends like you two........I should become a monk.

"Me? No. Come on. Don't be crazy. I know the wrestlers get all the fancy ladies, and the clothes, and the fancy creams and lotions. But my life is good! Really good! I get to wake up every morning, at 5AM, and make some soup! It's the best. I love it...." - Nacho Libre

[Jake]

I'm very interested in the outcome; please keep us informed.

Mine is doing the same thing but usually around 35 to 45, but not all the time.

I had a mechanic ride with me and he thought it might be the converter lock up.


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[RF Overlord]

Well, 3 days later and Mary says there's still joy in Mudville. :burn:

Only thing I can figure is that the new plugs require less voltage to fire, so are not stressing the COPs as much. I'm going to suggest that she get all new ones.

Jake, if you're having the same issue Mary's car did, I guarantee it isn't the torque converter. Next time it happens for you, try this: while it's happening, hold your foot steady on the gas and with your other foot, gently tap the brake pedal, just enough to light the brake lights. If the shuddering immediately stops, you have the infamous torque converter clutch shudder and changing the ATF will fix it.

[RF Overlord]

*update*

Almost 2 weeks later and Phoebe is still running strong. I still don't believe the problem was the plugs all along, but...can't argue with success. :rasta:

[Jake]

OK, I finally found the time to address this problem.

Thanks to RF Overlord I did the trans test on the way home and found it wasn't a trans issue.

So I installed the NGK plugs per MartyO's suggestion and now, four days later, she is runnin just fine!

Thanks MartyO!


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[FX1]

ive been having the same issues. My guy thinks its one of my coils??? I have 127k on them now so I might replace all of them anyway? Which brand should I go with plugs also thanks

[Krytin]

ive been having the same issues. My guy thinks its one of my coils??? I have 127k on them now so I might replace all of them anyway? Which brand should I go with plugs also thanks
OEM coils from on site vendor Sparta Performance - I just did mine @ 133K miles. Big difference! You won't be disappointed!!

[FX1]

Thanks I looked into the Sparta site and its showing 2 different ones. I'm ready to order but half to be sure. Any further help is greatly apreciated. Thanks in advance.

[Richy04]

Just a heads up, if you are running a tune. Certain tunes will not always throw a check engine light or even show a code for a misfire. You may have to go back to a stock tune and drive it around to have it log the problem. Then it will come up as a P coded misfire and the cylinder causing it and then you can read it/identify it with most hand held OBDII readers.

[RacerX]

Thanks I looked into the Sparta site and its showing 2 different ones. I'm ready to order but half to be sure. Any further help is greatly apreciated. Thanks in advance.
M-12029-4V
https://id144237.webhosting.optonline. net/spartaperformance.com/merchantmanager/product_info.php?cPath=53&products_id=356
Just got them recently myself. :)

[Krytin]

M-12029-4V
https://id144237.webhosting.optonline. net/spartaperformance.com/merchantmanager/product_info.php?cPath=53&products_id=356
Just got them recently myself. :)
Yep ^^^^^^^^^^^^^

[tomhilmes]

How did you fix the issue?

[RF Overlord]

See reply #39.

[FX1]

Well my problems fixed. Thanks to a little research and help from the ones on this here forum. I went with new COPS from Sparta performance. I feel like she's a Marauder again. Can't wait to order a tune next!!!!

[tomhilmes]

Can you test a cop with a meter or other method? Which brand is preferred?

[RF Overlord]

You can test for a short or open, but there are failures that will only show up under load, or when the coil gets hot, so simple meter testing is not a complete test.

Primary should read approx 0.5 to 0.6 ohm and the secondary approx 5.5k ohms.