Hey yall, let me start with saying i am by no means a wizard when it comes to working on cars, just a young kid trying to solve a mysterious issue. Anyways here it goes, so i started having an issue with my 3V GT a couple weeks ago on a long drive home from a weekend vacation. The car was starting to buck/sputter under harder acceleration, didn't quite sound like a misfire however it very well could be classified as one since it causes my car to pop louder than normal. Anyways i pulled over and checked under the hood didn't see anything unusual so i plugged my FIXD tool in to scan for any issues/codes and it came up with nothing! Even stranger no check engine light and the idle of the car was completely normal nothing out of the ordinary. So i hopped back in my car and started driving again, i was able to drive 200 miles on it just fine. This issue ONLY occurs when i give the car throttle with a heavier foot; when i build up the rpms a little slower it has no problem at all. So with that being said, here are the things i have tried to do to fix this issue since it started a couple weeks ago:

My car is a 2006 GT with 88,000 Miles. Car is bone stock other than a catless Xpipe & muffler delete.

1. I purchased CRC MAF Sensor Cleaner & Throttle Body Cleaner. I applied them both generously and accordingly.
2. I purchased brand new spark plugs and installed them.
3. I changed the fuel filter (Old one was cooked!).
4. I purchased 8 new coil packs.
5. Even tried a new gas station.

I have tried all of these and it has not fixed this issue, HOWEVER! Changing the coil packs / Spark plugs has made the issue much more noticeably tamer. It only bucks 1-2 times when i accelerate on heavy foot to the pedal; compared to my previous several sputters. So hopefully i am on the right track to conquer this issue at home instead of handing it over to the good ol' boys in blue at ford. Thanks for reading! Please help!! 😅

 

It sounds like you may have a problem with the throttle position sensor. Unfortunately the intermittent nature of it makes it difficult to diagnose and it's tempting to throw parts at it in the hope that you might just get lucky.
A Ford dealership will charge an arm and a leg to perform diagnostics, only for the technician to inform you that he couldn't replicate the problem.
Since the car is still drivable and mostly running well, I suggest you live with it for now and when it does get worse, it'll become easier to diagnose as it's more likely to trigger a fault code or trip a CEL/wrench symbol.

 

i'm leaning toward fuel pump related issue. could be pump itself or filter sock that is attached at bottom of pump.

 

Yeah! Could be. I agree i'll let her be for the time being, hopefully it doesn't progress. 😅 (Although i will say i took the car for a drive this morning and it strangely didn't do it once!?) Thanks for the reply

 

Totally could be, have read about a couple 3v's around that 80k mark who've needed to swap that darn thing out. Thanks for the piece of mind

 

the issue is from cavitation or bubbles in the fuel by the pickup that get worked up from constant higher speeds. im not sure if its because of the speed of the fuel pump itself, the vibration of the car at certain higher speeds or what. you cruise at 80 for an hour and go to pass, mash the pedal and the car sputters for a second then catches and goes, thats the air bubbles getting sucked into the fuel line then fuel behind them. there is a TSB for this issue, ill see if i can find it and edit my post. TSB 06-9-9.

06-9-9.pdf (stangpit.com)

credit to poster in other forum. good luck

 

That makes alot of sense! I have spent ALOT of time cruising on highways on the 80-90mph ball park! I appreciate this information. Thanks!

 

welcome

 

I had this problem with my '06 GT 'vert. It would happen after being on cruise control for a while. I read somewhere it is a fuel pump problem that has since been fixed. I bought a GT500 pump and installed it, problem fixed. They say after being on cruise for a while, bubbles build up around the pump intake and when you step down, the pump sucks in the bubbles causing the car to buck. I guess that was it because I never had the problem again. Good luck

 

A momentary stumble upon acceleration after a long highway cruise is a known issue. For most it's no more than a minor nuisance but it if does it every time after a long cruise, the solution is to replace the fuel pump with the updated version from '07+.