1991 FORD FESTIVA Service Manual

Fig. 22: Single Injector
- Known Good - Voltage Pattern
EXAMPLE #5 - CURRENT CONTROLLED DRIVER
These two known-good waveform patterns are from a Chrysler 3.0L V6 VIN [3]. The first waveform, Fig. Fig. 23
, is a dual trace pattern that
illustrates how Chrysler uses the rising edge of the engine speed signal to trigger the injectors. The second waveform, Fig. Fig. 24
, was taken
during hot idle, closed loop, and no load.

Fig. 23: Injector Bank
- Known Good - Voltage Pattern
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Fig. 24: Injector Bank
- Known Good - Voltage Pattern
EXAMPLE #6 - CURRENT CONTROLLED DRIVER
This known-good pattern from a Ford 3.0L V6 PFI VIN [U] illustrates that a zener diode inside the computer is used to clamp the injector's
inductive kick to 35-volts on this system. See Fig. 25
.

Fig. 25: Injector Bank
- Known Good - Voltage Pattern
EXAMPLE #7 - CURRENT CONTROLLED DRIVER
This known-good waveform from a Ford 5.0L V8 CFI VIN [F] was taken during hot idle, closed loop, and no load. See Fig. 26
.
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Fig. 26: Single Injector
- Known Good - Voltage Pattern
EXAMPLE #8 - CURRENT CONTROLLED DRIVER
These two known-good waveform patterns are from a GM 2.0L In-Line 4 VIN [1]. Fig. Fig. 27
illustrates the 78 volt inductive spike that
indicates a zener diode is not used. The second waveform, Fig. Fig. 28
, was taken during hot idle, closed loop, and no load.

Fig. 27: Single Injector
- Known Good - Voltage Pattern
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...

Fig. 28: Single Injector
- Known Good - Voltage Pattern
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00010328
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Back To Article
GENERAL INFORMATION
Wheel Alignm ent T heory & Operation
* PLEASE READ THIS FIRST *
PRE-ALIGNMENT INSTRUCTIONS
GENERAL ALIGNMENT CHECKS
Before adjusting wheel alignment, check the following:
Each axle uses tires of same construction and tread style, equal in tread wear and overall diameter. Verify that radial and axial runout is
not excessive. Inflation should be at manufacturer's specifications.
Steering linkage and suspension must not have excessive play. Check for wear in tie rod ends and ball joints. Springs must not be
sagging. Control arm and strut rod bushings must not have excessive play. See Fig. 1
.

Fig. 1: Checking Steering Linkage

Vehicle must be on level floor with full fuel tank, no passenger load, spare tire in place and no load in trunk. Bounce front and rear end
of vehicle several times. Confirm vehicle is at normal riding height.
Steering wheel must be centered with wheels in straight ahead position. If required, shorten one tie rod adjusting sleeve and lengthen
opposite sleeve (equal amount of turns). See Fig. 2
.
Wheel bearings should have the correct preload and lug nuts must be tightened to manufacturer's specifications. Adjust camber, caster
and toe-in using this sequence. Follow instructions of the alignment equipment manufacturer. NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
CAUT ION: DO NOT attem pt to correct alignm ent by straightening parts. Dam aged parts MUST be replaced.
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Fig. 2: Adjusting Tie Rod Sleeves (Top View)

ADJUSTMENTS
CAMBER
1. Camber is the tilting of the wheel, outward at either top or bottom, as viewed from front of vehicle. See Fig. 3
.
2. When wheels tilts outward at the top (from centerline of vehicle), camber is positive. When wheels tilt inward at top, camber is negative.
Amount of tilt is measured in degrees from vertical.

Fig. 3: Determining Camber Angle

CASTER
1. Caster is tilting of front steering axis either forward or backward from vertical, as viewed from side of vehicle. See Fig. 4
.
2. When axis is tilted backward from vertical, caster is positive. This creates a trailing action on front wheels. When axis is tilted forward,
caster is negative, causing a leading action on front wheels.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
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...

Fig. 4: Determining Caster Angle

TOE-IN ADJUSTMENT
Toe-in is the width measured at the rear of the tires subtracted by the width measured at the front of the tires at about spindle height. A
positive figure would indicate toe-in and a negative figure would indicate toe-out. If the distance between the front and rear of the tires is the
same, toe measurement would be zero. To adjust:
1) Measure toe-in with front wheels in straight ahead position and steering wheel centered. To adjust toe-in, loosen clamps and turn adjusting
sleeve or adjustable end on right and left tie rods. See Fig. 2
and Fig. 5 .
2) Turn equally and in opposite directions to maintain steering wheel in centered position. Face of tie rod end must be parallel with machined
surface of steering rod end to prevent binding.
3) When tightening clamps, make certain that clamp bolts are positioned so there will be no interference with other parts throughout the entire
travel of linkage.

Fig. 5: Wheel Toe
-In (Dimension A Less Dimension B)
TOE-OUT ON TURNS
1. Toe-out on turns (turning radius) is a check for bent or damaged parts, and not a service adjustment. With caster, camber, and toe-in
properly adjusted, check toe-out with weight of vehicle on wheels.
2. Use a full floating turntable under each wheel, repeating test with each wheel positioned for right and left turns. Incorrect toe-out
generally indicates a bent steering arm. Replace arm, if necessary, and recheck wheel alignment.
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STEERING AXIS INCLINATION
1. Steering axis inclination is a check for bent or damaged parts, and not a service adjustment. Vehicle must be level and camber should be
properly adjusted. See Fig. 6
.
2. If camber cannot be brought within limits and steering axis inclination is correct, steering knuckle is bent. If camber and steering axis
inclination are both incorrect by approximately the same amount, the upper and lower control arms are bent.

Fig. 6: Checking Steering Axis Inclination

Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00060716
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