Car falls flat on it's face @ 3200rpm

[Ford_w/loctite]

Hey guys! I'm new to the MM community, but not new to cars. However, my experience with fuel injection is amatuer to say the least! So i have a question that has me perplexed and a little concerned. I have an early '03 MM, it has 70K miles on it, with no performance mods (YET!!). The problem I am experiencing is at WOT the car will run up to around 3200rpm then it'll "fall on it's face" and actually drop 100-200 rpm only to pick right back up and accelerate normally. Am i just experiencing the cam "opening up" or could this be a fuel delivery issue (e.g. pump cavitation or worse)? Thanks in advance for your help!

Josh

[merc]

Have you changed your fuel filter yet ?

[Ford_w/loctite]

Yes, fuel filter in brand new! I've also replaced the IAC recently.

[ts-pa]

Were you below 1/4 tank of gas?

[Ford_w/loctite]

She does it on a full tank.... :(

[captain]

when did it start?
any time you remove the iac or replace it....you must dissconnect the neg. battery cable...wait 5 minutes...then restart the car...do not drive it...let it idle for 15 minutes....or take it to the dealer to have it zeroed. this device actually measures engine wear and makes adjustments accordingly. Also clean the Maf sensor.

[Ford_w/loctite]

Come to think of it, it did start around the time i replaced the iac. i did however clean the MAF when I replaced the iac. I also did disconnect the battery to let it reset when I changed the iac, but I was unaware of the 15 minute idle time. I'll try reseting it again and let it idle, then I'll let you guys know if it goes away (Won't get to it till this evening). Thanks!!!

[Wags]

Ford_w/loctite,

You are describing what many had with very early builds (FDH2 and before). Mine did the exact same thing that yours is doing. I solved it by chipping the car years ago. Or you can re-program the box. You can tell what version of code you have by a little sticker that is on the driver's side front door.

Wags

[Ford_w/loctite]

This evening I reset the computer & let the car idle as recommended. I must say there is a noticeable difference now! Thanks Captain! However, there is still a hint of in WOT operation, it's just not as "pronounced". I'm assuming that this could reasonably be solved with a chip. Y/N?

All this leaves me with two questions for you guys (Aside from the assumption above):

1. Who can I contact to get my build date?
2. What is the recommended chip and why? (I've seen SCT, Diablo, even a Jet chip)

Thanks again guys!

[CanadaMarauder]

Mine did same thing and it was Fuel pump cavitation! Felt like it wouldn't go into 2nd sometimes too...
Dealer did pump and all fixed

[xopher]

This evening I reset the computer & let the car idle as recommended. I must say there is a noticeable difference now! Thanks Captain! However, there is still a hint of in WOT operation, it's just not as "pronounced". I'm assuming that this could reasonably be solved with a chip. Y/N?

All this leaves me with two questions for you guys (Aside from the assumption above):

1. Who can I contact to get my build date?
2. What is the recommended chip and why? (I've seen SCT, Diablo, even a Jet chip)
You can PM RoyLPita your VIN for build details, althought I'm not sure if he has the date.

As for the chip, I think more MM owners use SCT than anything, but probably because two large MM vendors, Lidio Iacobelli of Alternative Automotive (http://www.mercurymarauder.net/forums/showthread.php?t=13722) and Dennis Reinhart of Reinhart Automotive, use and distribute the SCT Xcalibrator 2, 9X00 series with custom tunes from their shops. Both are supporting vendors of this site and have excellent options to meet your needs (http://www.mercurymarauder.net/forums/showthread.php?t=42491). Search here at mm.net and send them a note or give them a call for more details.
If you want to fully customize your tune, Diablo, which ships with the FIT blower, may have some tweaks and tricks that the Xcal2 doesn't have, but many people here use and understand the Xcal2 alot more.

Hope this helps!