Progress Thread Giving an abandoned 88 GT project a new chance at life

[jaketractor]

Hello, my name is Jacob I am 20 years old, and am not new to Mustangs, but I am new to the Foxbody platform.
I found my Foxbody on Facebook marketplace last summer (early June). It is an original California GT but I believe that is where the originality ends.
It seems to have been manual swapped as the shifter bezel doesn't fit without trimming (SEE PHOTO) .
The previous owner also claims that the motor that is currently in the car came out of a 94/95 Mustang. The motor has been dressed with all of the original Foxbody accessory drive.
The car also had a Cobra computer(X3Z SEE PHOTO) in it when I bought it but had the factory injectors and no MAF installed. I was able to get it to turn over with a wrench when inspecting the car before purchase so I knew that I had a decent chance of getting it running.
The previous owner had recovered the car from his mechanic after the car had sat in pieces for about 6 months. He wasn't mechanically inclined enough to rebuild the car, this is why he wanted to sell it.
Once I got the car home I was able to get it to run very briefly with some starting fluid but I still had a long way to getting it running and driving.
I started by updating the MAF plug from the 88 California MAF to the 89-93 MAF plug to make it easier to find parts. I also had to re-run the TFI wiring as the mechanic had no idea how to do electrical work and it was too big a risk to keep moving without fixing the "twist and tape" wiring. I also had to order intake piping because there was none in the car when I purchased it. I also had to get a MAF housing which my buddy was nice enough to give me as he had an extra. With this work, I was able to get the car running a bit longer but the fuel pump decided to go out at this time. I replaced the fuel pump, fuel level sender, and fuel filter and cleaned and painted the tank since it was already out of the car. After getting it back in the car I was able to get the car to idle but it was idling very poorly because of the mismatched computer and injectors. I ordered an A9L and this was able to get the car idling better. Now that the car was running better I realized I had a vacuum leak. I chased it for about 2 weeks until I finally found the leak from the unused AC vacuum system. The car was now ready for its maiden voyage around the block. It still ran like crap... I have an issue that I still cannot find.
I have replaced/checked

• TPS sensor, replaced with a new one and set at .98 volts
• MAF, brand new
• Fuel Pressure Regulator, Brand new
• Timing, set at 12 deg (with the spout out)
• Distributor, Brand new LMR replacement
• TFI, Brand New
• Firing Order, checked and rechecked
• Spark Plug Wires, Ford Performance Black Wires
• Coil, Brand new also check with a different known good coil from a friend's car
• Factory Replacement Injectors, Brand New (Ignore GT40 Lower in the photo ended up taking off to restore)
• Alternator, Converted to 3G and checked the wiring
• Ignition Switch, Brand new

The car is consistently cutting out at 2500 rpm when sitting in neutral and at a stop.
The car is bucking and kicking at seemingly random RPMs when driving.

• When going uphill the car performs as normal if not a little down on power
• When going downhill the car surges and tries to buck if you press the gas at all
• When cruising on flat and level ground, if you let off the throttle at all the car surges and bucks at any RPM above 2500 (SEE VIDEO)
• Large Voltage Drops when free revving or shifting (SEE VIDEO)

I

I have some issues with the car that I am unsure if it affects the situation that I am currently having, but I am going to list them in case they are a variable.

• No AC/ Heat including the removal of the fuse to said system
• EGR Delete with block off plate
• The carbon Canister is missing but the solenoid has been blocked off
• Smog pump is installed but no lines are connected (The holes behind the heads have been blocked off
• No Cats (Aftermarket H Pipe w/o smog pump holes
• Intake has been redone and reseated with no leaks coolant or vacuum-wise (stock Foxbody intake)
• 4-cylinder gauge cluster
• Mini starter upgrade
• Exhaust Leak at headers (there are a few that I am chasing down)
• Aftermarket shorty equal-length headers

I ran the codes and only received a few (KOEO)

• 31 ORC EVP circuit below minimum voltage
• 85 O Canister Purge (CANP) circuit failure
• Code 11 On the Continuous Memory

I have attached photos of how I got the car, the previous owner's handy work, the shifter location, and some videos of the issue I am facing at the moment.
Any advice would be greatly appreciated. Thank you guys for being so welcoming. I really love this Foxbody platform and I would love to get to enjoy this car.

 

[Noobz347]

It sounds like (and maybe I missed something) you need a Cobra MAF sensor and 24lb injectors.

 

[jaketractor]

Hello, my name is Jacob I am 20 years old, and am not new to Mustangs, but I am new to the Foxbody platform.
I found my Foxbody on Facebook marketplace last summer (early June). It is an original California GT but I believe that is where the originality ends.
It seems to have been manual swapped as the shifter bezel doesn't fit without trimming (SEE PHOTO) .
The previous owner also claims that the motor that is currently in the car came out of a 94/95 Mustang. The motor has been dressed with all of the original Foxbody accessory drive.
The car also had a Cobra computer(X3Z SEE PHOTO) in it when I bought it but had the factory injectors and no MAF installed. I was able to get it to turn over with a wrench when inspecting the car before purchase so I knew that I had a decent chance of getting it running.
The previous owner had recovered the car from his mechanic after the car had sat in pieces for about 6 months. He wasn't mechanically inclined enough to rebuild the car, this is why he wanted to sell it.
Once I got the car home I was able to get it to run very briefly with some starting fluid but I still had a long way to getting it running and driving.
I started by updating the MAF plug from the 88 California MAF to the 89-93 MAF plug to make it easier to find parts. I also had to re-run the TFI wiring as the mechanic had no idea how to do electrical work and it was too big a risk to keep moving without fixing the "twist and tape" wiring. I also had to order intake piping because there was none in the car when I purchased it. I also had to get a MAF housing which my buddy was nice enough to give me as he had an extra. With this work, I was able to get the car running a bit longer but the fuel pump decided to go out at this time. I replaced the fuel pump, fuel level sender, and fuel filter and cleaned and painted the tank since it was already out of the car. After getting it back in the car I was able to get the car to idle but it was idling very poorly because of the mismatched computer and injectors. I ordered an A9L and this was able to get the car idling better. Now that the car was running better I realized I had a vacuum leak. I chased it for about 2 weeks until I finally found the leak from the unused AC vacuum system. The car was now ready for its maiden voyage around the block. It still ran like crap... I have an issue that I still cannot find.
I have replaced/checked

• TPS sensor, replaced with a new one and set at .98 volts
• MAF, brand new
• Fuel Pressure Regulator, Brand new
• Timing, set at 12 deg (with the spout out)
• Distributor, Brand new LMR replacement
• TFI, Brand New
• Firing Order, checked and rechecked
• Spark Plug Wires, Ford Performance Black Wires
• Coil, Brand new also check with a different known good coil from a friend's car
• Factory Replacement Injectors, Brand New (Ignore GT40 Lower in the photo ended up taking off to restore)
• Alternator, Converted to 3G and checked the wiring
• Ignition Switch, Brand new

The car is consistently cutting out at 2500 rpm when sitting in neutral and at a stop.
The car is bucking and kicking at seemingly random RPMs when driving.

• When going uphill the car performs as normal if not a little down on power
• When going downhill the car surges and tries to buck if you press the gas at all
• When cruising on flat and level ground, if you let off the throttle at all the car surges and bucks at any RPM above 2500 (SEE VIDEO)
• Large Voltage Drops when free revving or shifting (SEE VIDEO)

I

I have some issues with the car that I am unsure if it affects the situation that I am currently having, but I am going to list them in case they are a variable.

• No AC/ Heat including the removal of the fuse to said system
• EGR Delete with block off plate
• The carbon Canister is missing but the solenoid has been blocked off
• Smog pump is installed but no lines are connected (The holes behind the heads have been blocked off
• No Cats (Aftermarket H Pipe w/o smog pump holes
• Intake has been redone and reseated with no leaks coolant or vacuum-wise (stock Foxbody intake)
• 4-cylinder gauge cluster
• Mini starter upgrade
• Exhaust Leak at headers (there are a few that I am chasing down)
• Aftermarket shorty equal-length headers

I ran the codes and only received a few (KOEO)

• 31 ORC EVP circuit below minimum voltage
• 85 O Canister Purge (CANP) circuit failure
• Code 11 On the Continuous Memory

I have attached photos of how I got the car, the previous owner's handy work, the shifter location, and some videos of the issue I am facing at the moment.
Any advice would be greatly appreciated. Thank you guys for being so welcoming. I really love this Foxbody platform and I would love to get to enjoy this car.

No I'm sorry if I didn't make it clear but I now have an A9L and factory MAF and Factory Injectors

 

[Noobz347]

Track down your leaks.

Clear codes.

Try to let it get to operating temp and pull KOER codes.

Drive it if you can (a few minutes) and pull KOEO codes again. The ones you listed above are negligible so long as the vacuum lines are capped.

 

[Noobz347]

After that, I would highly recommend this:

clicky clicky

Thread 'Help me create the "Surging Idle Checklist"'

Apr 10, 2005

Updated 05 July 2022 to add rough idle when cold and smooth idle when up to normal operating temperature. See the EGR tech information, section #15 for more help.

Many of you are familiar with the "Cranks OK, but No Start Checklist for Fuel Injected Mustangs" checklist and the No Crank Checklist. They are very effective in finding and eliminating the problems by use of a systematic process that checks and eliminates possible causes. This idle problem checklist will use the same troubleshooting strategy and methodology.

By the term surging idle, I mean an idle that...

• jrichker
• 1986 1993 86-93 check engine light code 67 cranks ok dump codes eec-iv mustang no start
• Replies: 575
• Forum: Fox 5.0 Mustang Tech

• 

 

[AeroCoupe]

Mechanically the transmission appears to be sitting way too high. Take a look at the transmission crossmember and it should look like this:

It may be failing motor mounts but I would suspect from the quality of the swap they hosed the transmission install. If you can get the transmission down like it is supposed to be you will need to get another shifter boot and cut the hold a little bigger to clear the Pro 5.0 shifter (same one I have). This will keep the exhaust fumes and heat out of the interior of the car.

https://lmr.com/item/LRS-7277E/79-04-Mustang-Lower-Shift-Boot-With-Metal-Ring

A new shifter bezel would clean things up as they notched the one in the car which should not have to happen. Will also need a shifter boot. Both can be had at LMR or the like.

Also, where the mechanical engine temperature gauge is connected needs to be removed. This is where the ECT (engine coolant temperature) sensor goes and it critical to the ECU controlling the engine. The wiring appears to be there so you would just need to buy the ECT sensor and install it. YouTube video here:


View: https://www.youtube.com/watch?v=UJw5mLZRMEg


There should be a braided wire grounded to the firewall and I believe the driver side cylinder head. My car does not have one as I built all my cables so I did it a little differently but you need a ground from the battery to the frame, frame to the block, and it helps to have one from the firewall to the engine.

An orange wire from the injector harness should be grounded on the back intake bolt on the passenger side. Its #19 in this diagram:

Also, make sure the ECU ground behind the battery is in good shape:

This is just what I can see from the pictures you have posted. Someone had no clue as to what they were doing before you got this car so be patient and work the problems as they present themselves.

 

[jaketractor]

After that, I would highly recommend this:

clicky clicky

Thread 'Help me create the "Surging Idle Checklist"'

Apr 10, 2005

Updated 05 July 2022 to add rough idle when cold and smooth idle when up to normal operating temperature. See the EGR tech information, section #15 for more help.

Many of you are familiar with the "Cranks OK, but No Start Checklist for Fuel Injected Mustangs" checklist and the No Crank Checklist. They are very effective in finding and eliminating the problems by use of a systematic process that checks and eliminates possible causes. This idle problem checklist will use the same troubleshooting strategy and methodology.

By the term surging idle, I mean an idle that...

• jrichker
• 1986 1993 86-93 check engine light code 67 cranks ok dump codes eec-iv mustang no start
• Replies: 575
• Forum: Fox 5.0 Mustang Tech

• 

Thank you for this link I'll have to go through this when I have some time.

 

[Noobz347]

Thank you for this link I'll have to go through this when I have some time.

It will help you identify anything that is not operating in the proper range. Take your time and don't skip around.

 

[jaketractor]

Mechanically the transmission appears to be sitting way too high. Take a look at the transmission crossmember and it should look like this:

It may be failing motor mounts but I would suspect from the quality of the swap they hosed the transmission install. If you can get the transmission down like it is supposed to be you will need to get another shifter boot and cut the hold a little bigger to clear the Pro 5.0 shifter (same one I have). This will keep the exhaust fumes and heat out of the interior of the car.

https://lmr.com/item/LRS-7277E/79-04-Mustang-Lower-Shift-Boot-With-Metal-Ring

A new shifter bezel would clean things up as they notched the one in the car which should not have to happen. Will also need a shifter boot. Both can be had at LMR or the like.

Also, where the mechanical engine temperature gauge is connected needs to be removed. This is where the ECT (engine coolant temperature) sensor goes and it critical to the ECU controlling the engine. The wiring appears to be there so you would just need to buy the ECT sensor and install it. YouTube video here:


View: https://www.youtube.com/watch?v=UJw5mLZRMEg


There should be a braided wire grounded to the firewall and I believe the driver side cylinder head. My car does not have one as I built all my cables so I did it a little differently but you need a ground from the battery to the frame, frame to the block, and it helps to have one from the firewall to the engine.

An orange wire from the injector harness should be grounded on the back intake bolt on the passenger side. Its #19 in this diagram:

Also, make sure the ECU ground behind the battery is in good shape:

This is just what I can see from the pictures you have posted. Someone had no clue as to what they were doing before you got this car so be patient and work the problems as they present themselves.

I'll throw the car on the lift and dig into the transmission once I sort out the drivability issues because I want it to look original again.
I have the ECT sensor installed now but it didn't affect my situation.
I'll look into all the other grounding/ wiring stuff you mentioned.
Yeah, the previous "mechanic" had no clue what he was doing. I'm making sure to take my time and fix the issues correctly.

 

[rednotch]

First thing I would do is yank the engine harness out, find out what year its from, if 88 wire in the Maf add on harnessess plug correctly and strip all the loom, check the whole harness for splices/ shorts, replace fuse links if needed, ditch all this butt connectors and scotch locks and terminate the wires correctly, retape and wire in the vss if it has one. Check the voltages of every sensor to make sure there in range then see if its still cutting out under load. That's 100% an electrical issue.

 

[AeroCoupe]

I know you have a lot on your plate with this car but the drive line angle needs to be addressed before you drive the car any more. By this I mean the drive shaft angles relative to the transmission to the drive shaft and the drive shaft to the pinion on the rear end. With the transmission that high up it has changed both those angles. Addressing this will keep unwanted harmonics out of the drive train.

I was a controls engineer in a high speed manufacturing plant and everyone there thought if there was a problem that they could just call one of us and we could connect to the PLC (think ECU) and program out mechanical or electrical deficiencies. You need to have a solid mechanical drive train and then make sure the sensors and harness are in tolerance and good working shape. Doesn't matter which one you start first but you need to have all of this working correctly for the ECU to get the right information to do its job.

 

[2000xp8]

I agree, fix the trans issue first, unless the car was hit and hit hard, it should be one of the easiest fixes.
You have to fix it all anyway, might as well have the drivetrain properly aligned before it drives and damages something else.
The engine has to be out of whack in multiple directions, it's clearly high and to the right.

 

[KRUISR]

If you haven't changed it yet, that 4 cyl cluster will show RPM at double actual. So when you say its having issues at 2500 rpm, if that reading is on the 4 cyl tach, then the issues are really at 1250 rpm. Its not going to fix or change your issues, it just shows you what is actually happening.

 

[gkomo]

updates?

 

[jaketractor]

Alrighty, I got home over spring break to try out your suggestions.
I started by replacing the ground wire from the battery to the engine block and from the block to the frame.
Call me paranoid but I also added a grounding wire from the battery straight to the frame, right under the battery tray.
I also cleaned any ground wire that I could see in the engine bay and that solved my issue. My engine idles better and revs all the way out without any hiccups or cuts. I went back through the harness but I didn't have the time to pull it out of the car I was able to ditch a lot of the "jank" wiring that was causing me headaches. It is going to get pulled out and re-loomed this summer but I am still in school and I don't get much time to work on this car.
I checked the engine mounts and transmission mounts like you guys said and they are all pretty tired so they are getting replaced this summer as I ran out of time to fix it that week.
Again I want to thank you for all the help and suggestions.
I hope to have some more good news this summer to add to this thread to document the revival of this car.
Here is a picture of its current state from the exterior.

 

[AeroCoupe]

Nice man! Keep grinding on those grades and summer will be here in no time.

 

[Flyboy60]

Keep the updates coming. Schools out or doing summer classes.

 

[jaketractor]

Hey all, I apologize for the lack of replies, summer has been crazy busy working on my other cars so the foxbody didn't get much work because I was using it almost everyday as my honorary daily driver.
I was able to get some of the pressing issues sorted out though.
The transmission mount on the car side was tweaked and was what was pushing the transmission up, this has been sorted out and the shifter is now in the normal position but the transmission and motor mounts are still pretty tired and are gonna be replaced when I have the time.
A buddy and I installed the Maximum Motorsports subframe connectors which made a huge difference in feedback.
I replaced the failing harmonic balancer (see photo) with a power bond unit from Summit
I was able to get my hands on a set of GT40 heads from a buddy for $100 and they were in good condition. So now I'm collecting parts and saving money aside for some machine shop work and a full Heads, Cam, Intake upgrade.
Right now based on limited research because of my busy schedule I'm planning on doing

• Ford Performance stainless valves
• Trickflow upgraded springs
• Port matching the GT40 intake I've had on the shelf
• 24lb injectors
• 75mm throttle body
• EGR delete
• 24lb Pro M MAF
• 1.72 rockers

The only thing that I am still trying to figure out is what Cam to go with. I would really like to keep the ability to street drive the car but I want to utilize the heads and other upgrades to there full potential (with the stock A9L computer) . I open to suggestions for that part.

It should be noted that while this upgrade takes place I will be replacing the lifters, timing cover, water pump, and timing set. I will also be doing some supporting mods like 3.73 gears and a fresh LSD clutch pack as well as a diff and transmission fluid flush. If there is anything else you recommend replacing for reliability reasons I am all ears!

 

[Noobz347]

Include the best looking clutch and ring from your old pack, in your traction lock rebuild.


Uh... I'm sure there's an article here someplace.



Aha! I need to add this to the Tech Index:

Drivetrain Post in thread 'C-clip Install Problem After Trac-lok Rebuild'

Oct 5, 2012

If you put too many extra disks or plates, the clutch pack is too long to get the C clips to fit....

This was copied from someone here on Stangnet, My apologies for not getting your name so that you could get credit for it.

Part # for the 8.8 Traction lock rebuild kit is M4700A. See Ford Dealer or www.mustangparts.com

It helps if you have a good manual but the instructions that come with
the kit are pretty good. The part number is F5AZ-4947-BA. It lists for a little over $60 at Ford but Mean Mustang Supply has it cheaper if you can wait. Get about 3 quarts of 80w-90 gear...

• jrichker

 

[AeroCoupe]

If you can just get the valves lapped then really no reason to replace them. I would let the machinists make that call. I would trim your throttle body back to a 65mm as you are not going to benefit from a 70 or 75 with your setup. Also, no real reason to move up to the 24 lb/hr injectors with that setup. The 19's should be just fine so I would spend $100 or so on just getting the 19's sonic cleaned and make sure when they do that they replace the screens in them, new pintle caps, and new o-rings. Other thing you can to that will help is to replace the 58mm MAF with a 70mm MAF. Here is a good thread on which vehicle to get the stock MAF from and it works with zero tuning. Only thing you have to do is buy an adapter.

C

Engine Thread 'Maf Sensor Help Please!'

Jun 18, 2017

Hi, want to change my maf sensor for a bigger one the one I have is stock and I think is 55mm.
I read on some forms that the maf from a thunderbird will fit and that is a direct bolt on.
So I went and got one dron the junk yard today.
I got one dron a 97 thunderbird and I need to know if this will work with my Foxbody 93 with 19 lb injectors and if is a bolt on, I need to know if it worked fine and if I will have any problems?


Is my first time posting something here so just learning.
I really need your help .

Thanks.

• Cabrera93stang
• Replies: 40
• Forum: Fox 5.0 Mustang Tech