Info:- Variations Between Mk1a's(pre 1987) and Mk1b's(post 1987)
- The very early Mk1a front bumper is flat at the front & normally painted matt black.
- Front bumper bar iron on Mk1a is different than Mk1b, but interchangeable if you fit the complete bumper skin and foam insert (Paul Woods)
- Mk1a does not have central locking from the door key, Mk1b does.
- Mk1a has smooth wing mirror housings, Mk1b has textured effect.
- Very early Mk1a had no side skirts from new, *later 1a's (Paul Woods)& Mk1b did.
- Mk1a had black moulded door & panel protector strips, Mk1b have colour coded clear plastic strips.
- Mk1a cars had front mud flaps as well as rear flaps, Mk1b only had rear flaps.
- Very early Mk1a had black unpainted plastic rear sill protectors.
- Mk1a bonnet different from Mk1b but are interchangeable(Paul Woods).
- Very early Mk1a had black caps on wheel nuts.
- Mk1a has metal (some plastic, Paul Woods) lower front spoiler, Mk1b is plastic. Also Mk1a has different front panels.
- Mk1a has triangle alloys, Mk1b has teardrop alloys. Mk1a 5.5J & Mk1b 6J , so Mk1b are slightly wider. (MartG)
- Mk1a engine cooling grille is metal & was split into two sections, Mk1b was plastic & single entry type which protruded further outwards from the body.
- Mk1a had roof mounted manual aerial, Mk1b had electric aerial mounted on the rear o/s wing.
- Mk1a only had sunroof & tintop options, Mk1b had T-bar, Sunroof & tintop options.
- Very early Mk1a sunroofs don't have a dot pattern on the blackout paint. Mk1b's do.
- Mk1a had two tone seats, Mk1b are single coloured.
- Mk1a interiors ( excluding seats, headlinings & sunroof cover ) were all black.
- Mk1a original radio very basic compared to Mk1b radio/tape player.
- Inner door handle backing plates on Mk1a different thickness to Mk1b & not interchangable between the two.
- Mk1a wiper / headlight knobs are squarer and angled downwards compared to the Mk1b's rounded type.
- Mk1a has no glove box key lock, Mk1b does.
- Mk1a headlights don't rise on the first switch position, they don't have dim/dip, so its side lights only. Mk1b lights do rise on the first position & operate in dim / dip mode with side lights.
- Mk1a has a sub woofer under driver's seat, Mk1b didn't have this. Some JDM spec later models do have a sub (Paul Woods)
- Between seat cubby box has lid support on Mk1b only, not on Mk1a.
- Mk1a had only one behind the seat coat hook, Mk1b had two.
- Mk1a inner door cards are different than on Mk1b, switches sit in a semi-circular pod, although the switches are interchangeable.
- The air vents at either end of the dash on a Mk1a have chrome centre knobs, Mk1b had black only.Radio surround on Mk1a is different to Mk1b & incorporated a small light.
- Centre arm rest on a Mk1a incorporates a padded arm rest, Mk1b doesn't.
- On a Mk1a the ashtray is located forward of the gearstick, on a Mk1b its to the side of the centre console.
- Heater controls on a Mk1a are basic design with levers & knobs for air flow etc, on a Mk1b they are push buttons with green L.E.D's & motorised direction flaps.
- The Mk1a heater control panel incorporates the cigarette lighter, on a Mk1b this is housed under the ashtray flap & the cigarette elements are not interchangeable.
- Lights up warning buzzer found on Mk1b only.
- Instrument ( and radio ) lights on Mk1b had dimmer switch fitted.
- Mk1a boot trim is different shape to Mk1b & not interchangeable.
- Mk1a boot has fibre board covers over the inner wing area behind the o/s/ & n/s boot panels. (Kev)
- Mk1a has no radiator cover trim( rubber gasket on underside of bonnet instead ), Mk1b does. *to be confirmed - Mk1a may have had a cover but different
- Mk1a coolant filling procedure warning sticker on the engine lid is yellow, on a Mk1b its blue & white.
- Tyre pressure information sticker on the bottom of the drivers door on a Mk1a is different to Mk1b.
- Mk1a dash gauges have larger increments than Mk1b.
- Mk1a had no rear speakers, Mk1b did.
- Mk1a steering wheels had exposed metal supports, Mk1b's were covered.
- Mk1a steering wheel 2.5" larger than Mk1b (MartG)
- Mk1a had black front strut top caps, Mk1b's didn't
- ONLY Mk1b T-tops had front strut brace fitted as standard.
- The ECU is NOT interchangeable from Mk1a to Mk1b
- Mk1a's ECU is more aggressive for fueling than Mk1b
- .Mk1a weighs less than Mk1b. (Kev)
- Mk1a has different top radiator brackets to Mk1b. (Kev)
- Mk1a has two mounting bolts on the brake master cylinder, Mk1b has three bolts. (Kev) (or: Mk1a 4 bolts, Mk1b 2 - to be confirmed - Paul Woods)
- Air filter on a Mk1a is in the engine bay, on a Mk1b its in the boot behind the n/s boot panel. (apart from some "changeover" 1b's that had a 1a engine fitted as standard)
- Mk1a drop links are different length to Mk1b.
- Brake disc's are smaller on a Mk1a than Mk1b, but calipers are same size & interchangeable (just the piston bit of the caliper - the support bracket is different.(Paul Woods)
- Cam covers have 16 VALVE in blue on a Mk1a, on a Mk1b this is in red.(apart from some "changeover" 1b's that had a 1a engine fitted as standard)
- MAP sensor on a Mk1a is square, on a Mk1b this is rectangular & NOT interchangeable between the two models.
- Rear suspension subframe is different between a Mk1a & Mk1b.
- Mk1a have single jet injectors, Mk1b have twin jet, higher flowing injectors & are interchanglable providing the engine bay loom is changed between the two models.
- Mk1a TVIS comes in at a lower RPM than Mk1b.
- The air intake temp sensor on a Mk1a is on the TVIS manifold (after throttle body), on a Mk1b its on the intake pipe (before throttle body) (Jimi)
- Mk1a have a VTV dashpot under the throttle body acting on the throttle stop, Mk1b's don't have this. (Jimi)
- Mk1a has smaller clutch (200mm) Mk1b has larger clutch (212mm).
- Mk1a has smaller diameter rear anti roll bar than the Mk1b.
- Mk1a has C50 gearbox, Mk1b has C52 gearbox.
- Rear track rod control joints are different on a Mk1a than Mk1b.
- Struts are different on Mk1a than Mk1b & are not interchangeable without cutting studs & drilling holes.
- Mk1a:- big ends are 40mm dia. Small ends are 18mm dia. Mk1b:- big ends are 42mm dia. Small ends are 20mm dia (Jimi)
- Changeover cars (1987) tend to be a mix of components from both 1a'sand 1b's
Thanks go to Tony 'Jinxy' Froude for compiling this list.
Hats must be tipped to Jimi, MartG, Kev 'Crazylegs' Crane, Paul Woods and everyone else who contributed. You know who you are
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