Help needed intermittent no power issue

[bosscj72]

I am having an intermittent issue with my 2004 Marauder. After getting a tune done and having the fuel pump and fuel filter replaced during the tune (car has 113k) I have been experiencing a very frustrating intermittent problem with the car.

While driving the car home after the tune, the car under a very tight right turn lost all power, would not downshift no matter where I placed the throttle. When the car went past the turn and adjacent hill the speed and power picked up.

I drove the car more and it showed up both with right and left sweeping turns.

The place that did the tune reinstalled the fuel pump because they thought the screen may have got crimped/closed off causing the power cut out.

This too has not helped. A month later when I drove it, I was pulling on to the highway and went to accelerate and it flattened out again. It does Not downshift, it does not accelerate, it does not pick up at all. The car has new plugs, and is in very good shape. The tune netted 275hp and 296 lb ft of torque with just a cold air intake and tune.

Now that it is back at the shop (and during the drive there it didn't cut out at all!), they can Not recreate the issue!

Does anyone have any ideas what can be the cause of this frustrating issue? Any suggestions are appreciated. The fuel pump was a Motorcraft one and brand new!

Thanks.

Dave

[bugsyc]

intermittent electrical short...Have an electrical mechanic go through the wiring....very hard to find,especially when you're not sure what it is...Electricity is controlling everything on the car...The turning and then this happening is why I'm guessing elec....Good Luck

[Comin' in Hot]

There is a large wiring harness that runs behind the front bumper cover, it tends to chaf on the drivers side up behind the fog light where the bumper support(rod) attaches to the header panel. I would start by looking there.

[bosscj72]

Hmmmm. Yes everything is electrical controlled on these cars, but they are still mechanical first.

Could be that but the car doesn't shut off, no surging, volt meter doesn't go down etc... The fuel pump lead could be something but why when initially around turns and then just pulling onto the highway? Most of the time when floored it does what it should do, downshift and get up and go.

No problem like this before the fuel pump, fuel filter and tune were done. All of a sudden having a short show up is possible but I think checking what changed first may be more likely.

Thanks for your suggestions. Has anyone experienced something like this?

[MyO4Rawdur]

Most times when something changes youre automatically ready to blame the change but thats not always the case. Sometimes there is something about to fail anyway and then a change happens which causes you to see an issue.

What kind of tune was it a dyno or handheld? Possible that their program has a dead spot in it or they arent the best at tuning. Just an option if the car isnt stalling.

The short idea is pretty logical and I wouldnt doubt it again because it doesnt stall. I think you can rule out the physical fuel pump but maybe not the wiring. They may have knicked something or creased something during install that has nothing to do with the fuel pump. Just all things to look at because chasing down a wire thats gone astray is a pain in the a$$

[ajcook]

I have a similar issue with my '04. It would try to grab 3rd gear way too soon and the ignition would cut out... to the point of snuffing the engine a few times. Ford dealer blamed the Lighting Control Module and upgraded the network programming; that didn't work. Then they said it needed new plugs which I replaced because my backside hurt from the LCM work they did. New plugs didn't help, either. Installed Lidio's tune and the problem has virutally gone away... virtually because the cut out has happened a couple of times since but nothing like before. I'm thinking a shift solenoid or the TC lock up could be pulling excess current and tripping the ignition to cut out but I don't have the tools and Ford is too expensive. So in the meantime, I just live with it.

[tbone]

Check the throttle position sensor.

[fastblackmerc]

Check the wiring harness on the drivers side behind the cam cover. It may be rubbing on a bolt back there.

[fastblackmerc]

I have a similar issue with my '04. It would try to grab 3rd gear way too soon and the ignition would cut out... to the point of snuffing the engine a few times. Ford dealer blamed the Lighting Control Module and upgraded the network programming; that didn't work. Then they said it needed new plugs which I replaced because my backside hurt from the LCM work they did. New plugs didn't help, either. Installed Lidio's tune and the problem has virutally gone away... virtually because the cut out has happened a couple of times since but nothing like before. I'm thinking a shift solenoid or the TC lock up could be pulling excess current and tripping the ignition to cut out but I don't have the tools and Ford is too expensive. So in the meantime, I just live with it.

There is no way an LCM could cause that problem.

[martyo]

There is no way an LCM could cause that problem.

I agree with that.

[martyo]

We have put some test miles on the car, some with Dave is the car and we can not get it to show the problem.

We know for certain it is not in the tune. We have tuned countless Marauders and not a single one of them has done this.

Tomorrow I am going to take the car with me on a very long drive and put 80 or so varied miles on it to see if I can get it to duplicate the problem.

If we can get the problem to occur in our hands that will help in diagnosing/fixing it.

One way or another, we will figure it out.

[bosscj72]

Being intermittent is like searching for the holy grail with dark sunglasses on at night! Thanks to all who have made suggestions. I am confident Mo's team and Jeff will be able to figure it out.

With my luck it will run fine tomorrow.... Until I drive it home! I will video it next time if it happens again.

Merry Christmas to all and Happy New Year!

Dave

[martyo]

Being intermittent is like searching for the holy grail with dark sunglasses on at night! Thanks to all who have made suggestions. I am confident Mo's team and Jeff will be able to figure it out.

With my luck it will run fine tomorrow.... Until I drive it home! I will video it next time if it happens again.

Merry Christmas to all and Happy New Year!

Dave

I have bad luck so maybe it will act up for me tomorrow!

[martyo]

I personally put 85 miles of very varied driving on the car today.

I could not get it to act up no matter what I did. And for sure the car never lost "all power." In fact, I thought the car was pretty peppy and it drove well.

I would be happy to take a drive with you with you or me driving to have you show me when/what the car is doing.

Let me know what you think.

Thanks.

[bosscj72]

I guess the best thing for me to do is come and get it tomorrow. If it has never done it it likely will not do it during a drive together. I will make a video with my blackberry if it acts up again.

See you around 11 AM.

Dave