Five Mistakes Foxbody Builders Make, or What is Wrong with my Mustang?

Matthew outlines five of the most common issues with Foxbody Mustangs that cause them not to run right, and what to do to check for them and fix them on your car. Stay tuned to the end for a bonus problem and solution!

[jesseworkman]

I'm glad I found your channel because you really get down to the nitty gritty on the actual technical side that truly helps those that don't understand or haven't heard about on these cars. Keep up the great work Sir.

[Scrapla]

Had tapered seat plugs installed in my aluminum heads thank God only one of them gave me a slight problem. I now have the proper plugs installed.

[nedaCFilms]

Great point on covering spark plugs!!!

[bozyb]

4 years chasing ghosts... my fox had the wrong plugs in it !!! thank you!!!

[sstjacques]

Very informative, thank you. Still have my fox since new... and had done some mistakes you mentioned over the years, but older and smarter now.

[_moes_garage_]

Phenomenal video! Thanks for putting this together!

[baldeaglegarage]

Man I wish I would've seen this video before I started taking apart my Foxbody. Great Info!

[arturozarate]

In almost 25 years I cant tell you how many times I've had to bill someone or a shop for a simple timing error. It never fails that I get told, "Well hell yes I used a light!" "Timing is perfect Mr. I done it myself. 25° initial and 40° all in at 3k rpm." Hurts me real bad inside knowing I'm about to ruin this guys day when I ask about the "SPOUT". CRICKETS every the occasional deer in headlights lost in space gaze.

All great info, and very much needed! With the LS, OBD-II fuel injection, and millenials the EEC-IV of the Fox is as dead as Latin to most owners and "mechanics".

As a Senior Master Technician with FoMoCo I can appreciate the knowledge your spreading. No wonder at all you have one of the FASTEST Fox bodies ever!

[kevin_nagle]

@4:48 Also the lines. People think just because they have a 450lph pump & 80# injectors that their fuel system is up to the task of supporting 600hp... then they find out really quick that the factory fuel lines are limiting fuel flow.
For a typical bolt on 302 with a power adder I recommend the SVE ⅜" high performance fuel line kit. It's nice direct bolt on pre-bent ⅜ feed - 5/16 return stainless steel lines that mount to the factory points including the factory connectors. I use them on a 550 rwhp Fox with a 340 DW pump & 60# siemens deka injectors.
Anything more than that I recommend ½" or -8AN feed and 3/8" or -6AN return lines & an aftermarket fuel rail with a good pressure regulator.

[bobfisher]

I have that exact same car, bought it in 06. Thanks for the tips!

[Whitehorse]

Thanks for the tips own a 61, 000km fox all original that I drive it is an AOD but I have all 4r70w internals..

[olliej]

Thought you be talking about re-welded floors and electrical problems perhaps leaks.. loved the video! The spark plugs was very informative.. have been rebuilding/rewiring and finally driving an 82 frankenstein gt..

[jennymann]

I threw away my stock IAC valve over an upper intake leak but we're good "mistake" new IAC installed thanks for your information happy new year to you Sir

[eurocarpleurocarpl]

Mistakes:
1. changing headlights to ugly custom
2. Changing tailights to ugly custom/Cobra style
3. Changing front bumper to Cobra style.
GT is pretty as is!!!!

[rolandrodriguez]

You just taught me what I did not know about my 5'0 subscribing to learn more

[survivethrive]

Your videos are great!! And have helped me out tremendously and learning alot. I own a 1988 lx 5.0. Cheers 🍻 from the states... 🤝

[ariajefferson]

89 fox 5.0 first fired up shorty headers turned cherry red within a minute. No cats b303 cam gt40 intake/geads bored .30 over off road x-pipe 2.5 exhaust dumped 40series flow masters. Ive had and done work myself on my foxbodies for over 15 years. Ive had 6 never had this issue

[Bacongrease]

331 with AFR185 and a vortech v3 with 60LB injectors. What size pump? Right now on a 255 with a boost a pump module that gives me more voltage after 5 psi.

[jucedcustoms]

This is GOLD! Thank you for sharing your valuable experience and knowledge. What type plug is best for gt40p heads?

[HawgKeeper]

I really enjoy your channel and the many things to learn more about our Mustangs. Now after watching this episode, I too have a issue with my new rebuild that you mention. My 93 5.0 is stock, except for GT40P heads with upgraded Trickflow springs and a Crower 15511 cam. The car idles, starts fine, but it cuts out and loses power at full throttle about 4000-4500rpm. I'm beginning to think I need more fuel as the new stock pump is not enough. The injectors are new, stock 19lb. It never occurred to me that the mods I had done couldn't be handled by it. So what are your thoughts Matt? Question two, would I need to run a hotter/colder plug with this, as I'm using NGK TR5's gapped at .045. This engine is fresh, with less than 100 miles, but just doesn't feel as strong as it once was when it was completely stock. With 4.10's behind a AOD, you could punch it from a slow roll and she would want to go sideways!