Chapter 2
Upping the Ante

by Ryan King
5/06

While the original Project LX ‘87 Sedan was a 98,000 mile original that didn’t appear to be driven hard, it wasn’t all roses and sunshine. It needed of a lot of maintenance and a few repairs because of problems resulting from 98,000 miles of neglect.

After doing some research, I discovered that, at that time, the cost of repairing the car with factory parts was considerably more expensive than using quality aftermarket performance parts. It didn’t take me long to decide that rather than just have a stock 5.0, I’d test the Mustang’s legendary ability to adapt to performance modifications.

Since this car was completely stock, it was a Speed Density car. For those of you who are unaware of the history of the computer controls used in the ‘86-’95 5.0 Mustangs, there were two types of systems. The earliest computer controlled cars (‘86-’88) were fitted with Speed Density computers from the factory, which do not measure air flow and can’t correct for changes in air volume. They only measure other factors such as air density in the intake and its temperature. From the factors they can measure they correct for changing running conditions, but those corrections are made using a preprogrammed factor for the volume of air coming into the engine. The second type of computer used in 5.0 Mustangs is Mass Air Flow (MAF) and it adds the ability to read the volume of air being drawn into the engine, thus it can conform to a greater change in air flow characteristics which happens when modifying an engine. It’s these cars built from ‘89-’95 that spawned the legends surrounding the Mustang’s response to modifications. The real key to the Mustang’s ability to respond to modifications is the over rich tuning provided at full throttle from the factory (which allows for increased power until the air/fuel ratio is leaned-out too far), its ability to make corrections for changing running conditions during idle and part throttle operation merely keeps the car drivable during normal driving conditions once modified.

What that meant for me was that the modifications I was going to make to the ‘87 needed to have very little effect on the engine’s intake airflow characteristics to ensure that the car would remain drivable. Even though the Speed Density computer lacked the flexibility of the MAF, it was and still is more capable of performance gains in stock, un-tuned form than the carbureted performance cars of the past, so I was still looking forward to the kinds of performance gains I would find.

First on the list was a new set of tires. Although not engine related, good tires are imperative to an overall improvement in performance as well as a more balanced car and were necessary in this instance. The previous owner decided that it would be a good idea to run non-speed rated Road Hugger GTs on the car. The LX effectively shredded the almost brand-new tires within a couple of weeks. I chose to go with a set of factory-sized 225/60ZR15 Yokohama AVS S4 Z tires mounted on the stock wheels. I wasn’t please with the change in performance, though. Corners I could previously take at 75 MPH were reduced to 55 with the AVS S4 Zs. Not that they were all bad, straight line traction didn’t seem to be reduced and wet weather traction was actually improved, but the loss in dry cornering adhesion was a bummer.

Next on the list was an oil change. Not a big thing, but Mobile 1 synthetic and Prolong additive did a great job of loosening up the engine.

The oil change was quickly followed by a K&N air filter, which, again, seemed to make the engine spin easier. That was followed by a tune-up...which is where I ran into my first problem.

I chose an MSD E-core coil and a set of Bosch Platinum plugs to accompany the other performance tune-up parts. The coil buzzed like an angry hornet. In fact, it buzzed so much, I could here it inside the car while driving. That was an easy, if not cheap, fix, I simply replaced it with a Crane PS-91 coil. The other ignition woe, rough idle and spotty acceleration, which a friend, Mike Bower, owner of Lakewood Automotive, pointed out, was caused by the Bosch Platinums. Idle quality and misfire under load are apparently how they affect some ignition systems not designed for them so I replaced them with factory Motorcraft plugs and the ignition problems were solved.

Other modifications to the car included a Bassani catalytic converter equipped stainless steel X-pipe and a MAC Flowpath cat-back system. Both had a dramatic affect on the 5.0, but to be honest, I'm almost positive a lot of the improvement had to do with the plugged cats and mufflers in the original factory exhaust.

Although an improvement the exhaust swap didn’t occure without incident. The cat-back rubbed on one pipe and the low-end performance was soggier, but once the motor hit 3,000 RPM, it tore off like a screaming banshee. Eventually, due to engine deterioration-induced oil burning, I removed the X-Pipe and put a non-cat H-pipe from MAC Performance on the car. This resulted in more low-end torque from the tiring engine that seemed to occur without a loss of high-end horsepower.

Those repairs weren’t the only ones that needed to be done. I ended up changing a number of the sensors, but because of the problems I had with the spark plugs and coil I chose to use factory parts to avoid more running gremlins. Even though the change in spark plugs fixed the rough idle problem and spotty power under acceleration, there were continued idling as well as running inconsistencies. A self-diagnositic of the computer directed me towards the TPS (Throttle Position Sensor) as well as the EGR (Exhaust Gas Recirculation) sensor, but these didn’t completely solve the problem. This lead me to replacing random sensors since I didn’t really understand how the computer worked, nor did I have a factory diagnostic manual for it, which left me with no way of understanding how to diagnose it much less try to hunt down intermittent problems that didn’t show up in the computer’s error codes.

After multiple sensor replacements didn’t fix the problem, I was left with no other choice but to consider an internal engine problem as the source of the running woes. I was pretty sure the problem was a blown gasket but I wasn’t sure which gasket exactly. It appeared that it could be an internal vacuum leak as well as a minor head gasket problem. I decided to take a blanket approach and replaced all the upper end gaskets at once instead of waisting time and money ripping into the motor more than once to chase down the problem.

What I found when I got into the engine was a number of internal problems that combined to create the intermitent running problems as well as a few parts that needed to be replaced. The problems started with a leaking intake gasket and spiraled down from there with a head gasket lifting between two adjoining cylinders, warped heads, sticking lifters and an extremely worn timing chain. After all that was repaired, I was left with a dilemma: Keep the 100,000-mile injectors that could be fully or partially plugged or replace them with a new set. At this point I decided not to take any chances and replaced them (I had considered having them cleaned but injector cleaning was more expensive than replacement).

Even though I’d just spent a pretty penny repairing the engine, I was still jazzed about finding more performance and decided to make a small mod while I was in the engine: A 1” phenolic spacer from Ford Racing, which at that time was going by the name of Ford Motorsports.

With the motor back together, I found it ran with considerably more low-end as well as mid-range torque. It was also quieter and smoother and idled with much better manners. I was very pleased with the results considering the fact that at the time I was still learning how EFI worked. I was, however, sad that I only got two performance tests done on the car: I managed a best of 23 mpg and a 6.6-second 0-60 that was plagued with massive tire spin...the engine had indeed improved its performance...I just needed my driving to catch up.

Before I was done with the repairs I had replaced the fuel pump and clutch linkage with more Ford Motorsports pieces, the fuel sending unit, the water pump, all the coolant hoses, the heater core, the brakes and a host of other small parts that were neglected, but the results were that the car finally drove right. Sadly, in June of 2000, at 131,000 miles, the LX Sedan's throwout bearing gave up the ghost...in an alarming fashion. The bearing exploded in the bellhousing, dropping the clutch pedal to the floor and causing the drivetrain to squeal to high heaven. The reason for the failure was that the throwout bearing had worn grooves into the aluminum-bodied front bearing retainer and after being cocked on the input bearing retainer for so long, it wore at strange angles until finally it splintered into shards. I later discovered that premature bearing retainer wear was a fairly regular problem on early T5 transmissions with the all aluminum front bearing retainers and that Ford had since upgraded their T5s to an aluminum body with a steel input shaft cover to solve this problem.

It was at this point that I came to a cross roads that would end up deciding what direction this project would go for the next five years: Repair the throwout bearing and retainer and reassemble the tired car or really test the ability of the Mustang to accept modifications.

Of course, I decided to go the more adventurous route and start over with something a little more potent ;)

Stay tuned as things start to heat up!

Project LX '87 Stage 1 Specifications
Vehicle	1987 Ford Mustang LX Sedan
Exterior Color	Medium Shadow Blue Metallic
Interior	Blue Cloth
Layout	Front engine/rear drive
Engine	5.0L V8 (302)
Induction	Ford EEC-IV SFI; 60mm Ford throttle body; 19 lb Ford injectors
Horsepower	N/A
Torque	N/A
Transmission	Borg/Warner T5 5-speed manual; OD
Gears	3.35/1.99/1.29/1.00/.62/3.15R
Differential	Ford 8.8"; 3.08:1; Ford Traction-Lok limited-slip differential
Steering	Power assist; rack & pinion; 15.0:1
Front Suspension	Independant; 425 lb/530 lb coil springs; Modified McPherson struts; 1.3" swaybar
Rear Suspension	Solid; 200 lb/300 lb coil springs; Quadra-shocks; .83" swaybar
Brakes	Power assist; disc/drum; 10"/1.75" x 9"
Wheels	15"x7" Ford aluminum 10-Hole
Tires	225/60ZR15 Yokohama AVS S4 Z
Length	179.6"
Width	69.1"
Height	52.1"
Wheelbase	100.5"
Track	56.6"/57"
Curb Weight	N/A
CID/Weight	N/A
HP/Weight	N/A
Gas Mileage	23 mpg
0-60	6.6 sec
60-Foot	N/A
Eighth Mile	N/A
Quarter Mile	N/A
Skid Pad	N/A
60-0	N/A

Click image for Chapter 2 Work Photos.

Click image for Chapter 2 Completed Project Photos.

Click here for the Stage 1 Parts List