u/Regular-Promise-1552

🏁 She’s Finally Home — 1990 Mustang GT Restoration Update

After a lot of weekends, late nights, busted knuckles, cleaning, repainting, researching, and doing things over until I was happy with them… she’s finally home. 😂

This is my 1990 Mustang GT 5.0 5-speed convertible, and this has turned into way more than just fixing a few things. I've been slowly bringing this car back and trying to do everything the right way instead of rushing through it.

🔧 Recent work / maintenance

Water pump

Thermostat

New thermostat housing

Power steering pump

Power steering hoses

Belt tensioner

Alternator

Upgraded charging cables — 4-gauge

200-watt alternator

New battery cables/grounds

Spark plugs

Ford Racing spark plug wires

New ignition coil

BBK 70mm throttle body

BBK cold-air intake

BBK shorty headers

Flowmaster Super 44 exhaust

New diamond-clear headlight assemblies

Complete replacement headlight harness

3-point strut tower reinforcement triangles

Rear drum brakes — both sides

Replaced the leaking/seeping oil drain plug

Power steering system serviced

AC system completely gone through, including:

New AC compressor

Receiver/drier

Accumulator

Orifice tube

AC service/recharge

Viper two-way paging alarm with approximately 1-mile range

Kill switch

3M ceramic tint all the way around

💡 Electrical / appearance

I also spent a lot of time cleaning up the wiring and trying to make the engine bay look better instead of just throwing everything back together.

The new headlights and harness are in, everything was torqued to spec, and I’ve been cleaning and repainting different components along the way.

The goal isn't just to make it run — I want it to look like someone actually cared about the car when they open the hood.

🛞 What's next

The next major phase is the 5-lug conversion and four-wheel disc brake setup.

I'm planning on going with Cobra brakes, upgrading the rear to 31-spline, and eventually putting the gold mesh wheels I've been waiting on from LMR.

Those wheels have been a whole story themselves. 😂 They were originally supposed to be available around August 3rd, after waiting since around April/May. That date came and went, and now the ETA has been pushed out another 12 weeks.

Once those arrive, I can really get into the 5-lug/disc-brake conversion.

😅 And of course… there was a coolant scare

While filling the cooling system after the recent work, we found a significant amount of coolant coming through the BBK 70mm throttle body and into the cold-air intake/plenum.

That turned into taking the throttle body back off, drying everything out, checking the EGR spacer and gaskets, and trying to figure out exactly where the coolant was getting through.

Thankfully, I'm taking my time with this build, so instead of rushing it, I'm going back through everything and making sure the seals and connections are right before putting it back together.

Honestly, I'm really enjoying this project.

I'm doing most of the work myself, a few hours at a time, and I'm learning a lot along the way. Some jobs that I thought would take an hour ended up taking half a day. 😂

The rear drums were my first time doing drums, and one side took me about four hours. The second side should hopefully go much faster now that I know what I'm doing.

It's not a perfect car, and it's definitely not finished, but seeing everything come together after working on it piece by piece is pretty damn satisfying.

She's finally home. ❤️🏁

Still a LONG way to go, but this is probably the most work I've ever put into one vehicle, and I'm excited to see where it ends up.

First Time On Feet

1990 Mustang GT 5.0 5-Speed Convertible Restoration Update — Looking for Advice

I wanted to post an update on my 1990 Mustang GT restoration. I've been working on the car a few hours at a time and taking my time with everything instead of rushing through the project.

After completing the work I previously posted about, we torqued everything to specification and started putting the car back together.

So far, we have:

- Installed the new 200-amp alternator

- Installed new 4-gauge charging/battery cables

- Installed and wired the headlight relay harness

- Installed the 70mm throttle body

- Installed the BBK cold-air intake

- Installed the water pump, thermostat, and thermostat housing

- Installed the new power steering pump and hoses

- Installed the tensioner and alternator bracket

- Installed Ford Racing spark plug wires

- Installed new spark plugs and ignition coil

- Installed BBK shorty headers

- Installed the Flowmaster Super 44 exhaust

- Installed the 3-point strut tower reinforcement

- Installed new diamond-clear headlights

- Installed a kill switch

- Installed a two-way paging Viper alarm system

- Installed 3M ceramic tint all around

- Replaced the A/C compressor, receiver-drier/accumulator, and orifice tube

- Replaced the rear drum brakes on both sides

- Changed the oil drain plug because it was seeping slightly

We recently connected the battery and tested the new headlights. Everything worked, and the lights look great. We also added fluid to the power steering system.

The rear drum brakes were my first time doing drum brakes. The first side took me about four hours because I was learning as I went, but I expect the second side to go much faster now that I understand how everything goes together.

The latest issue is where I could use some advice.

We filled the radiator with distilled water and antifreeze/coolant. Shortly afterward, we noticed a small amount of liquid on the floor. After investigating, it appeared to be coming through the BBK cold-air intake tubing. We traced it further and found coolant inside the 70mm throttle body, and then found coolant inside the plenum/upper intake manifold.

We have now removed the throttle body and are drying out the inside of the upper intake manifold and intake tract.

At this point, we're not sure if:

- The EGR spacer gasket failed

- The throttle-body gasket failed

- There is an issue with the EGR spacer itself

- Or there is another problem that we haven't identified yet

We are going to reassemble everything with new gaskets and then pressure-test the cooling system before starting the car again. We also plan to remove a couple of spark plugs and inspect the cylinders to make sure no coolant made its way into the combustion chambers.

Has anyone with a Foxbody 5.0 experienced coolant getting into the upper intake/plenum, throttle body, and cold-air intake tubing like this?

If so, what ended up being the cause, and what was your course of action to fix it?

I'm open to any advice or suggestions before we put everything back together. This has been a learning experience, and I'm trying to do everything correctly rather than rushing to get the car running.

Thanks in advance to everyone who takes the time to read this and offer advice.

1990 Mustang GT 5.0 5-Speed Convertible – Slowly Bringing Her Back to Life

I’ve been working on my 1990 Mustang GT convertible a few hours at a time, taking my time and trying to do things the right way instead of rushing through everything. This has turned into a combination of maintenance, restoration, and upgrades.

So far, I’ve completed or had the following work done:

Engine / Cooling

- Water pump

- Thermostat

- Thermostat housing

- 70mm throttle body

- BBK cold-air intake

- New spark plugs

- Ford Racing spark plug wires

- New ignition coil

Electrical / Charging

- New 200-amp alternator

- New alternator bracket

- New belt tensioner

- New 4-gauge battery/charging cables

- Refreshed/replaced engine and vehicle grounds

- Headlight relay harness

A/C System

- New A/C compressor

- New receiver-drier/accumulator

- New orifice tube

- A/C system serviced and recharged

Power Steering

- New power steering pump

- New high-pressure hose

- New low-pressure/return hose

Exhaust / Performance

- BBK shorty headers

- Flowmaster Super 44 exhaust

Lighting / Exterior / Chassis

- New diamond-clear headlight assemblies

- 3-point strut tower reinforcement/brace

- 3M ceramic tint all around

- Kill switch

- Two-way paging Viper alarm system with up to a 1-mile range

I’ve also been cleaning parts and surfaces properly, repainting certain components for better aesthetics, and torquing everything to specification. I’m trying to keep the Foxbody character while making the car cleaner, more reliable, and more enjoyable to drive.

The project is still in progress, but the major mechanical, electrical, A/C, lighting, and exterior work is coming together. With the upgraded 200-amp alternator and new 4-gauge charging cables, the next big step is getting the car ready for the audio system.

This is my first time doing a lot of this work myself, so I’ve been learning as I go. I’m taking my time and enjoying the process. There’s something really satisfying about bringing a 35+ year-old Foxbody back to life one system at a time.

I’d love to hear from other Foxbody enthusiasts: what would you recommend checking, upgrading, or addressing next?

Resto

Refreshing the front end

Complete new AC system, thermostat/housing, water pump, 4g charging cables, 3g 200 wart alternator, headlight harness power steering pump, kill switch.

#project50