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Discussion Starter #1
Is a 1991 US spec spider L-jet or motronic? Pat Bradens all alloy twin cam companion book says it's L-Jet, but I have heard others refer to the series 4 spiders, and all 1990 and later alfas (164) as being Motronic. Anyone know?
 

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Motronic for sure. Came in as 1990 (as mentioned) on the series 3.5 like mine.

I don't think Braden particularly liked the later models and definitely gets it wrong. The Bible says no Motronic on Spiders at all and the Twin-Cam Companion says it was only on the 1994 C.E. Wrong on both accounts.
 

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Alfa Modifications
As the years go by, there are so many mods made to the cars, mostly in an effort to keep them running, but at times just for the fun of it, or perhaps to improve upon the original with an updated version. I have seen a few posts about changing things over, from perhaps a wreck or who knows. I use to have all my mods listed on the inner hood of one of my cars, thinking that if something happened to me, that whoever ended up with the car could make some since of what was there. But then I got a different hood.
 

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Discussion Starter #7
Thanks everyone for the information. I was sorta hoping it was l-jet since I am already familiar with it.

Doug
 

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Time for the usual discussion about injection, huh?

OK, well here's the short story about USA Spiders:

66-67: Series One (Duetto) Roundtail "Osso di Seppia" body style, 1600cc engine with two Weber 40DCOE carbs
68: No Spiders imported
69: Series One (Spider Veloce) Roundtail 1750 designation for a 1779cc engine with SPICA mechanical fuel injection
70: No Spiders imported
71: Series Two 'A' Kammtail with the 1750 engine
72: No Spiders imported
73-74: Series Two 'A' Kammtail with the 2000cc engine with SPICA fuel mechanical fuel injection
75-79: Series Two 'B' Kammtail with the newer federalized black rubber-covered 5mph big black rubber baby buggy bumpers - still has the SPICA
80-81: Series Two 'B' Kammtail but both years had a year-specific unusual SPICA setup (these are a little harder to work on)
82: Series Two/Three Kammtail this year saw a change to the Bosch L-Jetronic Fuel injection, but it maintained the Series Two 'B' body style
83-89: Series Three Ducktail Spoilers were added and different bumpers and grille. Many minor changes over the years (Rubber ducktail to hard plastic, dual to single dashpod, introduction of Veloce, Graduate and Quadrifoglio versions, etc) all equipped with Bosch L-Jetronic fuel injection.
90: Series Three/Four Ducktail this year saw the change to a Bosch Motronic fuel injection, while maintaining the Series three body style
91-94: Series Four Aerodynamica New body style with integrated bumpers, spoilers, etc. Power steering added. All cars equipped with Bosch Motronic fuel injection.

I have left out a number of various changes over the production run, but basically that is what was impirted to the USA. Other markets had Spiders with 1300cc and 1600cc engines for many more years, Dellorto carbs instead of the SPICA injection, etc. One could write a book about them (oh yeah, several already have!).
 

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Cefali said:
I was sorta hoping it was l-jet since I am already familiar with it.
The Motronic is basically the same as the L-Jet. Main differences (I can think of) are the L-Jet uses two separate ECUs, one for fuel and one for ignition while the Motronic uses one ECU for both functions. L-Jet uses two sensors at the flywheel for the RPM & ignition system trigger; Motronic uses one sensor at the front crank pulley. Motronic has a self diagnostic feature; L-Jet does not.
 

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Long live Motronic. Another feature is no cold start injector, two seperate relays one for Engine Motronic ECU w/diode (red stripe) and one without diode for fuel pump. AFM flapper does not have fuel pump switch.
 

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Cefali said:
Thanks everyone for the information. I was sorta hoping it was l-jet since I am already familiar with it.

Doug
Yeah, but Motronic is a better system. It's not THAT different and as mentioned has handy things like OBD diagnostics.
 

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So, here's my question: another poster here has stated that Motronic is "chipable", and therefore more power can be produced. True? Recommended? There is a very nice black '90 Graduate in ebay right now that would be very tempting as a replacement for my rather disappointing '89 Quad.

Because, at this high altitude (6200 feet), it is rather sluggish. Is there any adjustment I can make to the L-Jetronic to compensate? Or am I stuck with some sort of self-adjusting aspect of the system when it comes to atmospherics?

Thanks & cheers!
 

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Yes, motronic is "chipable". Not a big difference, but a difference. IIRC a Motronic stock has about 10hp over an L-Jet stock. Chip is supposedly good for another 5 to 10. That grad would be significantly lighter than your quad, I would expect.

As far as altitude goes.....well......that's just basic physics and chemistry. At your altitude (and mine) there's less oxygen - that's why the tourists huff and puff and get hammered so easily. The motor needs oxygen to burn the fuel. Less oxygen = less fuel = less power. You are "stuck with some sort of self-adjusting aspect of the system when it comes to atmospherics". The system gives the motor less fuel to go along with less oxygen. If it didn't, the car would run very "rich" - too much fuel relative to oxygen - and have even less power, polute badly, etc. That's a big advantage for fuel injection vs. carbs when driving in the mountains.
 

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Here's what Squadra claims: http://www.squadra-tuning.com/
I have one in my '91 and can definitely feel a difference. However, premium fuel is required with a Squadra chip.

Horsepower
Revs Standard Modified Difference
2000 32 37 5
2500 51 57 6
3000 68 75 7
3500 83 90 7
4000 96 103 7
4500 106 114 8
5000 114 123 9
5500 119 129 10
6000 118 128 10
6500 112 121 9

Torque
Revs Standard Modified Difference
2000 112 130 18
2500 143 160 17
3000 159 176 16
3500 167 181 14
4000 169 181 12
4500 165 178 12
5000 160 173 13
5500 152 165 13
6000 138 150 12
6500 121 131 10


Alfonse22 said:
So, here's my question: another poster here has stated that Motronic is "chipable", and therefore more power can be produced. True? Recommended? There is a very nice black '90 Graduate in ebay right now that would be very tempting as a replacement for my rather disappointing '89 Quad.

Because, at this high altitude (6200 feet), it is rather sluggish. Is there any adjustment I can make to the L-Jetronic to compensate? Or am I stuck with some sort of self-adjusting aspect of the system when it comes to atmospherics?

Thanks & cheers!
 

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Premium fuel is required for the stock ECU as well, so no loss there. I know mine pinged like mad when I accidentally used 87 one time.
 

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Basic physics and chemistry understood, Chris.

My question is how the L-Jetronic system works to apply itself when air pressure changes. I am assuming then, that the system self-adjusts to its most efficient settings, prioritizng air pressure, leaning out the fuel mixture, and I am stuck with whatever power loss results. I am also assuming there is nothing I can do about this, right?

Having a chipable Motronic system at our altitudes would have its avantages in regaining at least some of the lost power. Trading my '89 Quad for a lighter '90 Graduate might be a good prospect.

Conedriver's figures are quite interesting.
 
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