Progress Thread 1989 GT Hatchback Restoration

JasonRP

5 Year Member
May 25, 2018
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Annapolis
Hello All,
I was a Ford dealership tech for a few years in the early/mid 1990s, and I always wanted a 5.0 Fox GT, but never had two nickles to rub together to get one. All my buddies back then had them though.. There was a dude that worked at our dealership that would request me for oil changes on his mustang- it was a Caspien blue/gray two tone hatch, with turbine rims, and flowmaster 40 exhaust.. That thing was NICE!

Fast forward to now- I just sold my motorcycle which was not getting ridden much (tired of feeling guilty for not riding it, but it just wasn't getting ridden!) and got the idea I would look for an old Mustang Foxbody to fix up. They've crept up in value, so I was surprised to find one relatively complete for 2k- had pretty much everything I was looking for: Hatchback GT, 5-speed/T5, Turbine rims, not too molested with aftermarket parts/looks, not drag raced/mini-tubbed, etc. (I'm not knocking those things! I'm just after stock looks.) At first I wanted a caspien blue, but, this black has really grown on me!

This 89 needs a LOT of work, (I think I saved the car from becoming a part-out!) so, I'm happy to find this place.. And, I'm happy I found the car- as I was looking for a project. I think I will start a thread here to documenting the car restoration. It's been some years since I worked on cars much, and so I'm sure I will have a LOT of questions for you all- I'm looking forward to learning from you guys!

Here's what it looked like when I first got it home...

just_got_it_home.jpg

Jason
 
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I was looking for an old foxbody mustang- just like I always wanted back in the day (but couldn't afford!).. Here's what I got: a 1989 hatchback, 5.0 with T5, radio & AC delete, manual windows and door locks- pretty much a stock base model that somehow made it this many years without being modded. Carfax and odometer seem to agree (even though the odo has rolled- twice!) 247k miles! No registered collisions (although it does appear to have 1 replacement front fender on it), clean title, mostly owned by the same dude as near as I can tell.

The good:
-mostly stock- engine is stock, interior appears to mostly be there*, turbine rims in good shape, clutch/trans/engine appear to be good, not rusted shock towers or radiator support, body in decent shape for the age, dash fairly good**

The bad:
-floorpans are rusted through on passenger side (*this is why I say interior appears to be mostly there- cause it was already removed, and given to me in a pile), 3 outta 4 tires are wrong size (65 series- but at least I can drive it), leaking radiator, battery draw, power steering whine (not too bad though), quite a bit of rust on suspension, dash lights not working, doors not closing right, no passenger door handle, passenger rear fender appears to have been badly bondo'd, driver's door a bit dinged up, liftback won't latch, appears to have bondo at top of A pillars, window seals all dried and thrashed, etc. etc. etc.

Neither good nor bad I suppose:
-car appears to be factory A/C delete, manual windows, manual locks, bare steering wheel (no cruise, no radio buttons), and VIN confirms factory radio delete.

I've fixed quite a bit of stuff already:
1) Rustoleum rattle-can prime and paint hood- it's not permanent, but at least now the car is all one color!
2) Fixed current drain/draw- it was a bad alternator regulator. Replaced the regulator with an eBay Motorcraft NOS part, soldered in a new connector too. No more draw, battery charges fine.
3) Drilled out broken door handle remnants on passenger side, new door handle riveted in.
4) Replaced heater core (I consider this cheap insurance, even though when I got to the heater core- it appeared to have been recently replaced. Oh well, now it is new and replaced.
5) While I had the dash apart, I fixed several small cracks on the dash, replaced the broken instrument cluster cover mounts with epoxied in, 3D printed replacements and new speed nuts, cleaned instrument plastic, replaced all bulbs and cleaned contacts, re-assembled. Now dash lights work, no vacuum leaks caused (vents still motor around). Added missing speed nuts too, and made sure all screws were in place. Quick rustoleum on slightly surface rusted metal dash mounts.
6) Got off eBay replacement instrument cluster cover (mine had broken screw holes and extra holes in the back to match the broken dash mounts), mounted to fixed dash- looks great!
7) Replaced yellowed, dry-rotted, cracked and drilled headlights with new parts from LMR. This included an epic broken stud saga- which I was able to morph into McGuiver with a dremel to ultimately get the broken bolt out without screwing anything else up- it was close though! All proper nuts and bolts re-installed. Bulbs tested and cleaned throughout. Also replaced the cowl vent grill just in front of the windshield.
8) New water pump, thermostat, thermostat housing (motorcraft direct replacement), radiator and radiator cap, reservoir tank, all 6 new hoses (made sure heater core flow restrictor was in place!), serpentine belt, and idler pulley. Had a leak on the water pump backing plate bolts (and I torqued them too!) so I'll be replacing the gaskets with Felpro ones this weekend hopefully.

Once I take care of the water pump gaskets and I confirm no leaks, here's what's next:
-motor cap&rotor, plugs and wires, adjust timing, fuel filter, clean air filter (k&n filter on there now), oil & filter change.
-gunk, toothbrush, and rinse, then evaluate for engine leaks.
-brake eval and restore
-u-joints and driveshaft eval and restore
-door and hatch striker bushing r&r, replace door hinge pins if needed
-ID and fix "mystery orange wire" that appears to have come out of a steering column connector (I think this may be the intermittent wiper speed wire?)
-suspension eval and restore
-power steering leak eval, fix if needed, clean either way.
-New tires

THEN:
-cut out rusted passenger floorpan, fit new floorpan, weld in floorpan on passenger side. With leftover new floorpan metal, fix small through-rust in trunk area next to spare tire well.
-then re-seal and POR15 floorpan top and bottom, install new soundproofing, install new carpet.
-clean, evaluate, and re-install interior (repairing, re-painting, or replacing parts that need work)
-service rear end and trans.

THEN:
If/when I make it here, treat myself to professional paint and body work.. Although- the rustoleum paint jobs look pretty interesting- I'd be interested in seeing how well this can be done... BUT, we shall see.

Some progress pics:
NewHeadights.png

HeaterCore.png
fixed_dash.jpg
NewCoolingSystem.png
 
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Well damn you've done a bunch already!

Your plans are great, maybe think about subframe connectors one day, but for now keep on with what you're doing.
 
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Jason you seem to be off to a great start. I've subscribed and I'm real interested as to what you come with when you get around to dealing with that plastic dash.
 
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I'll be watching this progress. I like seeing these cars saved sand brought back to life.
 
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Thanks for the positive vibes everyone- this is a cool forum for sure!

Made some progress last week, will be doing more work today, if I can fix my garage door opener! :cautious: The carriage seems to hang out a little (about 2 inches) above where it should be (like the door is slightly open- but I can pull the unlatch cord and shut the door all the way).. When I press the button to open the door, the opener tries to shut the door first, then groans as it bottoms out, then goes back to where it's been sitting, and stops.. I'm guessing I need to adjust the close level slightly, more towards the open setting, so when it shuts, the carriage is stopping in the right spot? Kinda weird that this would happen outta the blue...

On the car front- I've re-done my water pump.. (funny, I used to be a Ford tech- and so I've gotten a "come back" on my own car! lol The culprit? I was over-thinking tightening those backing plate bolts, and had cautiously torqued them to 10ft/lbs.. This time, I made sure they were good'n'tight, leaving the torque wrench in the toolbox. Overall I'd cleaned everything up again, put in felpro gaskets between the plate and pump, and also between the plate and timing cover, and bolted it back up (15ft/lbs on the bolts/studs). Refilled, burped the system, topped off, and have run through a few heat up to operating temp. and cool back off cycles (plus it's sat for a few days too)- and knock on wood, still dry as a bone. While I was in there, I stupidly paid the 70 or so bucks for the Steeda aluminum idler pulley (stupid of me, because the car needs so much other stuff, but, hey- the car has earned it!) You can't really see it when the fan shroud is back in, but it runs silent! Plus, I know it is there! :) A high quality unit for sure- just make sure if you get one, install it with the circlip pointing towards the engine or you might have clearance issue with it spinning. New serpentine belt too. Good stuff! Idler tensioner system wear indicator is now perfectly in the "you're good" range.

Elsewhere, I replaced both door striker bushings (I have the hinge pins and bushings, but it doesn't seem to need them yet). I can't believe how much of a difference these striker bushings made! (The old ones were GONE!).. Now the doors both close like a new car, and they are firmly held in place when shut. This may be the best improvement for smallest amount of money possible? So far on this project anyways. Gotta do the trunk lid striker bushing still- it moves currently when shut, like 1/2"! Also, I think I've confirmed the "mystery orange wire" near the steering column connectors is the intermittent wiper speed wire. With that orange wire still disconnected, wiper low speed and high speed work, but intermittant does not. I think I need to lower the steering wheel again to push the contact back into the multi-function switch connector. Oh- and just to be totally OSD, I had a missing screw on the upper intake "5.0 HO" plaque, so I got a new screw for that, removed all screws, made sure the threads were all good, and replaced all 4 screws with just a tough of anti-seize on them.

Question for you guys: Anyone experienced "low windshield washer fluid" light on all the time (well, it does go off momentarily with the other idiot lights during the bulb check sequence at start up)? I've got plenty of washer fluid in there...Any way to get to the level switch without removing the drivers' side fender?

Next up: TUNE UP!
I've noticed, this motor has good oil pressure, no check engine light, starts up quick, and doesn't make any bad noises. However, it idles high 95% of the time (1500 rpm) and seems a bit slow to rev (it revs up, but seems to not return to idle as fast as I'd expect- it doesn't hang in the upper RPM range, but, it's not "snappy" to return either) Gotta fix that!

So far, I've taken the intake tube off, and cleaned up the throttle body butterfly and mouth with CRC throttle body cleaner spray, a toothbrush, and a rag. It is a lot cleaner now, but once buttoned back up, I noticed no change in idle behavior. I will next clean the IAC (I shoulda done this while I was cleaning the throttle body), and also I'm leaning towards replacing the PCV valve, grommet, and filter screen. Also, will test the Throttle Position Sensor voltage, and make sure it is adjusted properly too. Then I'll check the idle situation again. (I should mention- I have no idea how old the fuel is in the tank.. I need to add some fresh fuel, as I'm now on E anyways.

And, I have the rest of the tune-up to do:
-cap&rotor, plugs and wires, check/adjust timing, fuel filter, clean air filter (k&n filter on there now), oil & filter change.

Then on to brakes eval and restore, and some safety checks, like u-joint, suspension, driveshaft, etc. Looks like it is time to add another blank page to my ever increasing "to-do" list!


reseal_cooling_system.png
 
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Remove the wheel and inner fender liner to get to the low fluid sensor on the bottom. IIRC, the sensor is potted into the washer resevior and might not be replaceable without changing the entire bottle
 
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Remove the wheel and inner fender liner to get to the low fluid sensor on the bottom. IIRC, the sensor is potted into the washer resevior and might not be replaceable without changing the entire bottle

Thanks M5L5, I'll be looking into the brakes soon, and will check this when I'm in there.

Also, anyone think it's easier to just remove the hood to easily get to the PCV valve? Or should I just man up, assume crazy yoga positioning, and jump in there as is and just do it?
 
Man up, it's not hard to get at, the screen gets to be a challenge, use a pick that has an L tip. I've heard of guys running a large screw into it and pull it out with pliers, I pulled my upper intake so I could change all the vacuum lines back there.
 
Alright- I gotta man up and just do it! lol
I'll knock this out when I'm cleaning the IAC and doing the rest of the tune up. I have said L shaped pick- one of my favorite tools!
 
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Yeah it’s not bad. You have to use your feelers, you can’t see it. Look at some pictures of it so you know what to feel for. The screw trick works pretty well.
 
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Well, I had a few minutes to work on the car- so I cleaned the IAC motor, and re-installed it with a new gasket. No change to the idle- idles high, with occasional surging. I pulled the codes, and got an 81 and 82- related to thermactor bypass valve I think... I wouldn't think this would affect idle, unless there's a vacuum leak somewhere? I still need to test/adjust the TPS, and wanted to set the timing, but my timing light wasn't working last night- hope it only needs a little TLC to get going again!

The IAC was pretty dirty, so it was cleaned. Testing with ohm meter, it registered just higher than 10 ohms, which I think is good. testing each terminal to IAC case/ground, I got open circuit on one size, and a slight value on the other side, consistently.. Is this a short? Or, does this sound normal? I want to say it was like 3 Megaohm or something...

Gonna try to do cap/rotor/wires/fuel filter this weekend. Oh, and still gotta get the PCV valve and screen replaced too.
 
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Got my timing light working- old Sears cheap one- cleaned up the connector where the leads plug into it- now it's working, and I'm not asking any questions! :)

Set timing for a conservative 10*, just until I get the idle issue figured out and get more work done on the car/get it drivable, then later I will try to bump the base timing up slightly... No change to idle. Changed the PCV, boot, and screen too. No change to idle.

Checked the TPS... It was "within range" at 1.22- I screwed around with it until it was 1.1 or so.. I know this sounds high, but according to the coolaid I've been drinking, it should not matter once the computer adjusts it.. But, still no change to the high idle.

Read the codes again, now I have 32 in addition to the 81 and 82.

I'm starting to become convinced it is a vacuum leak. I will start checking in earnest- hope to have a better update tomorrow.

UPDATE:
Using an unlit propane torch, I 'gassed' around the vacuum connections- both of the trees, around the throttle body connections, around the connections to the FPR, the two thermactor air valves, the evap canister, etc. Absolutely no change in idle during any of this. I took vice grips, and shut the brake booster supply, no change in idle. Perhaps it's not a vacuum leak?

While I had the air cleaner out, I pulled off the evap cannister to intake manifold vacuum line and fittings (and the little purge valve). The ends of the vacuum hoses that connected to the valve were starting to split.. I tested this with a handheld vacuum pump (literally the only time I've ever used the mighty vac vacuum pump I bought years ago!) and it held vacuum unless I stressed the hoses, but still- they looked like crap so I changed these hoses too.

Had the battery unplugged for a good half hour. Hooked everything back up, started the car. Seems maybe the idle is slightly slower? Maybe placebo effect- but if it is slower, it went from 1600 to 1550 :) Maybe there is some truth to the TPS sensor needing to be adjusted to .92 volts? I really don't mean to start a mustang holy war here! What do I know anyways, I'm the new guy here! BUT, I do think if this thing was meant to be adjusted, one screw hole in the sensor would be oblong so that it could be moved, right? Mine allows only VERY slight movement. I was really thinking of leaving this sensor alone, but, I'm starting to become convinced that, unless one of the air bypass valves is stuck open, it's not a vacuum leak.

Any idears here fellers?
 
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It turns out I had to replace a very important thing- it was free to replace by the way. What is it you ask? I had to replace stupidity on my part! :) I disconnected the TPS, took it off to inspect it. Upon replacement, I noticed the tangs seemed to want to go right where the notch sticking up from the throttle was. So, I rotated the TPS so the notch wouldn't foul up on the tangs. Then rotated it so that the screw holes would line up- seems this put some preload on the TPS? Whatever the case, I tightened the screws, and re-checked it. This time, .91 - and I'm leaving it the heck alone! :) Still high idle!

So, after reading other threads here (Hey, search really does work! Who knew?) I tried unplugging the IAC and seeing if the idle went down. It did not. Last ditch effort- I tried turning the mechanical adjuster- guess what? The idle goes down, no problem... SO, I have no idea who's been in this car before me, and what they've done. I have no reason to believe that they weren't excellent mechanics- nothing was butchered that I can tell with the car! But, I checked most everything else- and I never did find that vacuum leak. I don't believe the codes 81 and 82 should cause a high idle either. With IAC still disconnected, I set idle (warmed engine) at about 650-700.. Then stopped the motor, plugged the IAC back in, and restarted it. I got idle at about 800 or so. I'm liking this so far.

Question for people with experience on this front here: If there's another issue with the car requiring the computer to raise the idle (or perhaps richen the mixture at idle causing a fast idle), eventually, the computer will just speed the idle back up, correct? I'll keep watching it just in case. Here's a little vid I took in the excitement of the moment:


View: https://www.youtube.com/watch?v=ms76aW65tc0


(*Disclaimer: That click-click-click-click right after the car starts is me making sure the car is in neutral, so that an un-planned drive through my garage wasn't part of this vid! Also, idle was a tad high in the video- and I think this is because I had let it cool off a smitch since it was last run, so I believe it would slow down a bit again. Now I'll have to go warm it up again and try...)

Next, I found and fixed the orange mystery wire! As the service manual suggested- it was indeed an intermittent wiper motor speed wire. Wipers worked in position 1 and 2, run once in intermittent, then don't kick back on. I had three wires missing in the multifunction switch connector. 3rd try was a charm, and now intermittent wipers work! To celebrate, I replaced the striker bushing on the hatchback. Now it shuts like a new car, and does not have play up and down when latched. Victory lap taken around the neighborhood confirms, with positively latched doors and hatch, there are less rattles and kooky squeaks when driving. It also confirms- homie gotta rebuild the brakes next! It stops, but it isn't confidence inspiring!

Lastly, I replaced the burnt out bulbs in the tag lights- I hope these are the same bulbs as the dash bulbs? Because that's what I plugged in there. They work, but both lenses are cracked up. I think a junkyard trip is in order for me- I want to find these, the trunk release button, and a grey driver's side sun visor (mine is trashed and frayed... I really don't want to go to Joanne Fabrics and buy fabrics and rebuild that visor myself, but I will if I have to , damnit!)

Another question I have: Car seems to hesitate just a bit if I give it a quick jab of the throttle, revving it in neutral. I haven't yet done the plugs, wires, cap, rotor, and fuel filter. These will be next. I know I know- I keep saying that!
 
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In the 5.0 technical/how to threads look through the surging idle checklist and you will find the process for the base idle reset, I always reset the computer after making certain adjustment s or changes, that may be all you need to do to get that idle to settle down, keep in mind it may idle a little high on cold startup, mine does but will settle down after a few seconds
 
You guys are AWESOME! I get to looking at this car in the garage, and my ADHD takes over- I want to jump to this or that. @General karthief suggestion to look at this thread (https://www.stangnet.com/mustang-forums/threads/help-me-create-the-surging-idle-checklist.698148/) was an awesome one! I'm not sure if I really have ADHD or not (doesn't everyone?), but when you work a full-time gig and can only sneak an hour in here and there to look at your car project, it's easy to get excited/disorganized. That checklist will keep me on the rails.

Also, I'm wondering- if the car's aftermarket airfilter (a long, inside the engine bay "cone") could contribute some MAF turbulance? You dudes might think I'm crazy, but I'd love to convert this car back to 100% stock, including the airbox (if I can even find one!) Anyone know if there's an online partsfiche kinda place, where I can see what parts are involved? Obviously there's the top and bottom of the box, and the filter, but wondering if there's anything else. Here's what my filter currently looks like:
airfilter.jpg


PS: I've been known to do this wacky, "back-to-stock" behavior before. Witness exhibit A:
original_tail.JPG

And after many parts were sourced, both new, and junkyard, and re-assembled:
rebuilt_tail.JPG


I know I know, stock isn't everyone's cup of tea, but, for me- it's what I like sometimes. Besides, a total butcher had been in there before- how there wasn't a fire back there I'll never know. This bike is sold now, and probably some punk kid has re-eliminated the fender and used wire nuts, coat hanger, and duct-tape in the process. I digress....

Anyways, sorry for the ramble! I'll continue along the checklist- I think I've licked the issue actually, but really should reset the computer and see. I also need to replace the fuel filter too- I've run some fresh gas with SeaFoam added too, to clean things up a little bit.
 
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