[Garman91]

Hey guys,

I'm new here, just bought an 02 Mustang V6. Has a few mods already so I'm wondering what's all been done to the car. It has a MagnaFlow H Pipe setup, BBK 70mm Throttle Body w/ Swirl Adapter and BBK Cold Air Induction System. The problem I'm having is this:

Low throttle input (All RPM's) motor runs like a dream

Half & Full Throttle in Low & High RPM Range feels like its running excessively rich or has a cylinder missing

However these only happen once the motor warms up, at a fresh start in the morning, motor will scream for 15 minutes or so then start to act up.

This afternoon I checked & replaced spark plugs (None were fouled up), replaced Throttle Position Sensor (No help) and the air filter just because

If anyone has any ideas, please let me know because I can't figure it out. Someone suggested plug wires but why would that be temp dependent? Possibly a timing issue? Again, why temp dependent. Has anyone else ever experienced this? Is the throttle linkage on the throttle body miscalibrated? Thanks in advance - sorry for writing a novel, I like to be precise!

~ Garman91

[HMUSN]

sounds like the throttle body to me.

do you have any codes?

[Garman91]

Thanks for the advice. No check engine light so I haven't checked to see if it's spitting out any codes. What's the best way to check it - shops want $50 just to plug in a little hand held reader, any better way?

Also had a suggestion of ignition system, want to stop spending money fixing the problem and start spending to make it faster Thanks again for any input!!

[ByPopularDemand]

A bigger throttle body does nothing if you dont port match the upper intake...in fact it could hinder the cars performance

[HMUSN]

Originally Posted by Garman91 Thanks for the advice. No check engine light so I haven't checked to see if it's spitting out any codes. What's the best way to check it - shops want $50 just to plug in a little hand held reader, any better way? Also had a suggestion of ignition system, want to stop spending money fixing the problem and start spending to make it faster Thanks again for any input!!

go to a parts store like kragens or autozone. they have scanners and will do it for free.

[ByPopularDemand]

How would it read a code that isnt showing...I think they wanna charge him for a diagnostic

[Garman91]

I don't want to take it to a professional. Any other ideas? So far I have

Throttle Body Configuration
Plug Wires / Distributor

Anyone have any other ideas to try before I really burn some cash? Thx!

[tnee_97stang]

im looking for similar problems online but cant find much. i know it cant be a miss fire in a cylinder because your check engine light would be on and flashing. you computer considers that catastrphic failure so it flashes but i agree with the above comment. it could be that the throttle body doesent match the port of the upper intake.

[Garman91]

Well. My check engine light did flash and come on for the first night I owned the car. After that, nothing. As far as the throttle body - I have the spacer between the plenum and the throttle body that tapers the throttle body bore to that of the plenum. Why would that cause a hesitation? Would it prevent air flow when the butterfly is open wider that say a "crack?" Very possible explination! I'm looking into it w/ a buddy who has a 450HP Stang on Saturday, I'll post the results.

Update on the condition: Seems to happen when the motor is under stress regardless of temperature, just more prevelant once it heats up. If the motor is casually accelerating (Low throttle input) it doesn't happen. Any time the motor is pushed the studder occurs.

[AtlanticBlue99]

if it is your fuel mixture rich, it is probably the front pair of oxygen sensors or maf, or similar a/f ratio controller. misfire could be b/c it ran rich and fouled a plug... pull your spark plugs and see how they look.

[scubasteve041186]

check the thing for a tune.....

[Garman91]

Originally Posted by AtlanticBlue99 if it is your fuel mixture rich, it is probably the front pair of oxygen sensors or maf, or similar a/f ratio controller. misfire could be b/c it ran rich and fouled a plug... pull your spark plugs and see how they look.

I replaced all 6 plugs and my buddy said they looked normal so I guess rich is out of the question

Originally Posted by scubasteve041186 check the thing for a tune.....

Take it to the shop for a standard tune up and see what the mechanic says? It's going to the shop for compression tests and general "checking out" on Tuesday - wish me luck!

[ByPopularDemand]

Shouldnt rich or lean have a code showing

[AtlanticBlue99]

usually. it could throw a number of codes depending if it were timing or spark, a/f mixture (oxygen sensors, injectors, maf, etc.)

if it isnt throwing a code, check fluid levels and leaks or vaccuum leaks. if you have a vaccuum leak, it will run sluggishly, but it shouldnt be only at high rpms...

[flames_blue]

I was planning on getting a T body spacer then later a t body. are these kinda problems normal? and do you have to program the car after you put it on or is it like a normal bolt on?

[ByPopularDemand]

normal bolt on but a TB spacer is useless. A bigger TB woulnt help unless you port the upper inake to match the size of the TB, otherwise it may hinder your performance

[flames_blue]

what does that do and how much would that cost?

[ByPopularDemand]

A TB with a ported upper intake would would allow more air into the engine...not too sure on the gains, or price...and the TB spacer will net you nothing

[flames_blue]

how do you port the upper intake?$$?

[Garman91]

All the spacer is good for is giving the 70mm butterfly clearance. Cant bolt the 70mm TB to the plenum cause the butterfly hits, spacer gives clearance.