Weird WOT Response and Bogging

[SAAAAAC]

Hello All,

My marauder has a Zack Tune and CAI and about 55,000 miles.

When I hit it at WOT, I get a laggy boggy response. When I actually do get a good launch I feel like the car should be giving me more. If I let off the pedal just a tad it seems to open up more. When it finally shifts into over drive at WOT it bogs horribly.

Anyone have any ideas what this could be?

I did have the plugs replaced at 50,000. I think they were those NKG Iridium plugs. Reinhart sent them to me. Had the dealership put them in. That's the only thing that's changed really.

I plan on cleaning my air filter. Not sure what else I can do.

Any help would be great. Thanks.

[bigdhasmoney]

Dont go WOT with overdrive on! The overdrive band is weak and people say they break easy at WOT. And i dont know about your situation lol

[SAAAAAC]

I only thought that you shouldn't go WOT while in OD with a rolling start. But from a dead stop its ok. Otherwise, I'd run out of gear. Plus the tune should prevent damage. Isnt that correct? I already broke a trans with the over drive issue.


Dont go WOT with overdrive on! The overdrive band is weak and people say they break easy at WOT. And i dont know about your situation lol

[CBT]

Interesting. You ever clean any underhood parts?

[justbob]

Sounds like a fuel pump going south. Have you datalogged the FPDC?

[ctrlraven]

Anytime you go WOT O/D should be off. You are not going to run out of gear unless you are doing a high speed/top speed run and at that case when you doing triple digits and running out of rpms then engage O/D.

Did the laggy/bog down just start or it has always done it? When it is the last time you replaced the fuel filter?

[SAAAAAC]

Interesting. You ever clean any underhood parts?

No I haven't. It was clean when I bought it with 25,000 miles. I'd say its time. I was going to start with the MAF and then the CAI. Any other suggestions?

[SAAAAAC]

How do I data log the FPDC? What is FPDC?


Sounds like a fuel pump going south. Have you datalogged the FPDC?

[SAAAAAC]

Triple digits is what i'm talking about when I say run out of gear. Why would it matter having it on or off starting from a dead stop? Its still going to engage one way or another? I completely understand why you should turn O/D off while rolling down the highway at 70 mph then smashing on it WOT.

The laggy bogging issue started about 5000-6000 miles ago.
I believe I had the fuel filter replaced at 50,000 miles because I remember having a fuel rail code come up after they did it. Had to clear it and it never came back after that.





Anytime you go WOT O/D should be off. You are not going to run out of gear unless you are doing a high speed/top speed run and at that case when you doing triple digits and running out of rpms then engage O/D.

Did the laggy/bog down just start or it has always done it? When it is the last time you replaced the fuel filter?

[CBT]

No I haven't. It was clean when I bought it with 25,000 miles. I'd say its time. I was going to start with the MAF and then the CAI. Any other suggestions?

Throttle body, the AIC or IAC whatevs it's called. EGR, all that good stuff. Fuel filter.

[justbob]

How do I data log the FPDC? What is FPDC?

You must have an Xcal2 or 3 with your Zack tune. Use the datalogging features on it or even better use it in conjunction with Livewire that can be downloaded off SCT's wedsite for free. Fuel Pump Duty Cycle (FPDC) IIRC 49% is max. Mine was maxxed out at 3/4 throttle most of the time (spurratic, spelling??) a couple years ago.

If all clears up when you let off the gas somewhat, it sounds like you are regaining enough fuel to run right again.

[ctrlraven]

Triple digits is what i'm talking about when I say run out of gear. Why would it matter having it on or off starting from a dead stop? Its still going to engage one way or another? I completely understand why you should turn O/D off while rolling down the highway at 70 mph then smashing on it WOT.

The laggy bogging issue started about 5000-6000 miles ago.
I believe I had the fuel filter replaced at 50,000 miles because I remember having a fuel rail code come up after they did it. Had to clear it and it never came back after that.
If all you have is a Zack tune, CAI and if you have stock 3.55 gears 3rd gear doesn't top out until like 140+ish mph. I topped out in 3rd on a dyno with 255/55-18 tires at 149 mph and with just the mods you have it will take some room for you to even get up to that speed.

I don't remember the specific reason why it should be turned off before any type of WOT run but Zack told me years ago and I have followed that. It's force of habit for me to turn traction control off and O/D before even putting it into gear. I only turn on O/D when I get on the highway or a back road 50-55 mph where I can cruise for miles at a time.

The fuel filter should be replaced every 12-15k miles depending on your driving habits. If I remember correctly some people that had bog/lag issues had a coil problem as well.

[SAAAAAC]

Duly noted on the WOT thing.

My fuel filter should be good.

I think I'll start by cleaning some things under the hood and look at the FPDC like justbob suggested.

Does anyone think it could be the throttle position sensor? And how would I test that?


If all you have is a Zack tune, CAI and if you have stock 3.55 gears 3rd gear doesn't top out until like 140+ish mph. I topped out in 3rd on a dyno with 255/55-18 tires at 149 mph and with just the mods you have it will take some room for you to even get up to that speed.

I don't remember the specific reason why it should be turned off before any type of WOT run but Zack told me years ago and I have followed that. It's force of habit for me to turn traction control off and O/D before even putting it into gear. I only turn on O/D when I get on the highway or a back road 50-55 mph where I can cruise for miles at a time.

The fuel filter should be replaced every 12-15k miles depending on your driving habits. If I remember correctly some people that had bog/lag issues had a coil problem as well.

[blazen71]

Fuel filter is a cheap fix. Even though it was changed at 50,000, it wouldn't hurt to do it again.

[whitey]

what about some bad fuel possibly? i would try cleaning all of youre air intake parts such as the maf, filter, and throttle body. after that, i would replace your fuel filter, even though its been replaced not too long ago, you could have had it filled up with bad gas, and it could be dirty again, or worse, such as a hoodlum/ex boyfriend:P could have put something into your tank....does it have a lock? start out with the cheap fixes, look at all the hoses and make sure theyre connected too.--whitey

[SAAAAAC]

Could be bad gas. Car did sit for a couple of months..... hmmm.





what about some bad fuel possibly? i would try cleaning all of youre air intake parts such as the maf, filter, and throttle body. after that, i would replace your fuel filter, even though its been replaced not too long ago, you could have had it filled up with bad gas, and it could be dirty again, or worse, such as a hoodlum/ex boyfriend:P could have put something into your tank....does it have a lock? start out with the cheap fixes, look at all the hoses and make sure theyre connected too.--whitey

[SAAAAAC]

Do you think a bad battery could have any effect? I have an original battery. Its not necessarily bad, just old. 10 years almost right? But doesn't the tune shut off the alternator at WOT?

[ctrlraven]

Fuel filter is a cheap fix. Even though it was changed at 50,000, it wouldn't hurt to do it again.
Also a perfect time to do the 3" filter mod that MuscleMerc sells, gets rid of the 90 degree plastic bends which can be choke points in the fuel line.


what about some bad fuel possibly? i would try cleaning all of youre air intake parts such as the maf, filter, and throttle body. after that, i would replace your fuel filter, even though its been replaced not too long ago, you could have had it filled up with bad gas, and it could be dirty again, or worse, such as a hoodlum/ex boyfriend:P could have put something into your tank....does it have a lock? start out with the cheap fixes, look at all the hoses and make sure theyre connected too.--whitey
+1. Make a list of all the things it could be from and then start checking things out.


Could be bad gas. Car did sit for a couple of months..... hmmm.
Throw some dry gas into the tank.


Do you think a bad battery could have any effect? I have an original battery. Its not necessarily bad, just old. 10 years almost right? But doesn't the tune shut off the alternator at WOT?
Anything is possible, when you do go WOT it does shut off the alternator briefly until the slightest throttle back off. A battery that old is just a matter of time until it gives out and leaves you stuck or starts making things act up in the car.

[Richy04]

My money is on a bad coil..

[Captain Dynball]

You must have an Xcal2 or 3 with your Zack tune. Use the datalogging features on it or even better use it in conjunction with Livewire that can be downloaded off SCT's wedsite for free. Fuel Pump Duty Cycle (FPDC) IIRC 49% is max. Mine was maxxed out at 3/4 throttle most of the time (spurratic, spelling??) a couple years ago.

If all clears up when you let off the gas somewhat, it sounds like you are regaining enough fuel to run right again.

He's definitely steering you on the right track. Also, if you haven't changed your fuel filter lately just start off with that since you need to do it anyways.

[SAAAAAC]

I did clean my CAI and MAF. No real difference, but the CAI tube was loose so I tightened all that up. Oh and when I took my CAI off, there is some oil in the little rubber hose that comes off the side. What is that about?

Next step is to look at the FPDC....

[Richy04]

Coils.. End of story..