WOT Bog and surging

[Fly007]

This is driving me nuts, I have an 03 with 4.10's, JLT Cold Air and a Lidio tune. The tune was done prior to the addition of the CAI. At WOT the car is just bogging and 1/2 to full throttle there is a surging. No check engine light or codes present, I changed the fuel filter thinking it was starving for gas and no luck. It seems to be almost intermittent also. Do I need to get retuned for the CAI? It ran great for a couple months after installing and now this popped up.
Any thoughts?

[fastblackmerc]

This is driving me nuts, I have an 03 with 4.10's, JLT Cold Air and a Lidio tune. The tune was done prior to the addition of the CAI. At WOT the car is just bogging and 1/2 to full throttle there is a surging. No check engine light or codes present, I changed the fuel filter thinking it was starving for gas and no luck. It seems to be almost intermittent also. Do I need to get retuned for the CAI? It ran great for a couple months after installing and now this popped up.
Any thoughts?

Is the MAF plugged in?

Is the MAF clean?

Is the MAF installed correctly?

Are the JLT clamps tight?

Basic PD - Always check the last thing done.

[MMBLUE]

Is the MAF plugged in?

Is the MAF clean?

Is the MAF installed correctly?

Are the JLT clamps tight?

Basic PD - Always check the last thing done.

All of these.:beer:

[Pat]

Sounds to me like you have one or more COPS that have failed, spark plugs could also be the issue. COP = coil on plug. To troubleshoot - buy one inexpensive COP and exchange it with the one's on the motor, one cylinder at a time until you find the bad one(s).

If you find COP(s) is the problem, then replace all eight with Motorcraft COPs.

If you need spark plugs (worn electrodes) there is a tutorial on the sticky page.

On these engines sometimes the spark plug threads on the head break down and the plug becomes very loose or even ejected.

No CEL's Illuminate.

Good Luck.

[RF Overlord]

What they all said ^^^, but especially Pat.

These motors are notorious for having misfires that don't light the CEL. Weak COP plus worn spark-plug electrode = misfire under load.

[Zack]

It will flash a CEL if you hold it at WOT from 0-90ish mph.

[Fly007]

Plugs only have about 20K miles on them, changed them when I bought the car. Already checked the clamps on the CAI, the coil pack would explain the intermittent nature of the issue and they are the originals with 118K miles on them so I am going to lean that way. Probably clean the MAF too while I am at it.

[Zack]

A coil pack connector may be loose.....the clips break

[silversnake]

+1 on coils being the issue


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[Marauderjack]

EGR Valve.....don't ask me why I suspect this!!:mad2:

[justbob]

Exact symptoms of when my fuel pump went out. Totally intermittent as well.

After almost a year of it I finally guessed and won with a new pump.


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[FF1077]

I had a very similiar problem. It was the Crankshaft Position Sensor. I chased all the things youve tried. New COP's and plugs. Changed the full pump even! The original owner of my car suggested CPS and since I had nothing to lose I changed it and problem was gone. Its very easy to change too.

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[Cabotwick]

Same issue and it didn't start until I installed the JLT.

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[Shaijack]

These cars are made to be driven like a grandpa drives. Don't go over 35 and never WOT.

[Black&Gifted]

Same issue and it didn't start until I installed the JLT.

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Clean the MAF.


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[crouse]

CRC makes an MAF Cleaner. About $7 for a can. Follow the direction on the can. I clean mine once per year. Sometimes the oil from the K&N style filters deposits oil on the fine wire inside the MAF.

[Fly007]

It was the coil packs, put a set of MSD's on she's all good now


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[Fly007]

CRC makes an MAF Cleaner. About $7 for a can. Follow the direction on the can. I clean mine once per year. Sometimes the oil from the K&N style filters deposits oil on the fine wire inside the MAF.



I have a can of that in the trunk, clean it regularly since the JLT is oiled.


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