Carb Vs Single Point Injection

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Sat 8 May 2004 12:10
Carb Vs Single Point Injection - grease'd monkey
Just by looking at an engine bay, how do you tell the difference between carburettors and single point injection? Also, multi-point injection has a fuel rail right? Just looking to clarify things!
gm...
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Sat 8 May 2004 21:29
Carb Vs Single Point Injection - Dynamic Dave

Simplest way is; if it's got a cat, then it won't have a carb. Which basically covers any car with a petrol engine made after 1992.

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Sat 8 May 2004 22:44
Carb Vs Single Point Injection - Doc
Simplest way is; if it's got a cat, then it won't
have a carb. Which basically covers any car with a petrol
engine made after 1992.



er, actually Rover Metros post 1992 had a cat and carb. on the K-series engine, until fuel injection was brought in.
They were exempt from the MOT cat test as they, of course, had no closed loop control system.


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Sun 9 May 2004 01:41
Carb Vs Single Point Injection - Dynamic Dave
er, actually Rover Metros post 1992 had a cat and carb.


I stand corrected.

I thought a carb wasn't sophisticated enough, hence the need for FI & electronic gubbings to prevent damage to the cat.

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Sun 9 May 2004 01:46
Carb Vs Single Point Injection - mfarrow
I here the Metro post 1992 carb had electronic idle control, so some electronics at least :-)

A rather strange hybrid of electrical and mechanical systems to do it that was I would have thought, though.
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Sun 9 May 2004 07:12
Carb Vs Single Point Injection - Andrew Moorey (Tune-Up)
Lift off the top of the air filter, An SPi unit has one hole with the injector centrally mounted with wires going to it, a carb will have one or two holes but will have a choke flap. Beware that in the early 90s Metro and Nissans used electronic carbs (shudder) also a few Escorts (shudder shudder). The Metro used a system of a pedal switch to effectively introduce a calibrated air leak into the carb to reduce the emissions at idle but only on the K series engine. Works surprisingly well once you suss out how to set them up! The metro had an unregulated Cat without Lambda sensor but the Nissan was a whole lot more sophisticated using electronic control to pulse the fuel shut off solenoid at idle to control emissions. A similar system was used by Lada but theirs was broken before it left the factory!
Andrew




Simplicate and add lightness!!
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Mon 10 May 2004 11:04
Carb Vs Single Point Injection - MarkSmith
Hi,

Nissan made the Sunny for six months in 1993 (or was it late 1992?) with cat and carb. (Not one of their best desicions.)

The "does it have a cat" test doesn't work anyway because a car could easily have single point injection and no cat - e.g. the (then) new-shape Rover 214 in 1990 had SPI and no cat.

Cheers,
Mark
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Mon 10 May 2004 11:38
Carb Vs Single Point Injection - Peter D
A single point injector has at least one and usually two multi pin connectors associates with it. A carb unit does not. Most single point injectors also have a stepper motor throttle stop. Regards Peter
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