Cold start assembly - any use?

Luke Hudson · 06-30-2003, 05:58 AM

Hi, I have a 1972 2.4TE with MFI, there's a cold start assembly attached to the engines' air intake. I was told that by removing the assembly I'd get more HP, is this the case?

The car only really gets fair weather use and although I live in England (no jokes about our weather please!) as I understand it the cold start apparatus is only really useful in winter conditions. Should I take it off and consign it to the parts cupboard?

derek murray · derek murray's Garage

The cold start nozzles for your year of car are not located in the air intake assembly (assuming you are running original equipment), but are mounted in the base of your intake stacks. The earlier cars, up to 1971, have the nozzles located in the air intake assembly as you describe.

However, having said that, if you do have the nozzles in the air intake assembly, I do not believe you would notice any increase in HP by removing the intake assembly.

FWIW, I just got my cold start system working a few months ago, and it now starts right away, whereas before it would take many, many turns of the key.

Luke Hudson · 06-30-2003, 07:16 AM

I think we're thinking about different things... maybe my description wasn't quite right, I'm talking about the apparatus in this picture on the left hand side of the engine, attached to the airbox via the large rubber hose:

(this is not my engine btw)

Tim Walsh · Tim Walsh's Garage

THat is an emissions control device to warm up your engine faster. I failed the NC inspection because of it although others have gotten away with it. It does nothing for performance or for cold starting. It just accelerates the warm up process.

Luke Hudson · 06-30-2003, 07:33 AM

Emmissions control? As I live in England and my car was built in 1972 i can pump out as much smog as i like without having to worry! No emmisions control law here!

I think I'll take it off, it appears to be surplus to requirement, a classic case of German over engineering!

Maybe the weight reduction will make me go faster too............

speeder · speeder's Garage

Actually, there is an advantage to getting car up to operating temperature quickly, particularly if used for short drives. The car cannot be flogged until fully warm, and oil stays a lot cleaner under these circumstances. I would leave it on since there is no performance gain, (or weight loss), from removing. And if it is over engineering, than the Swedes, Americans, Japanese, and the rest of the world is guilty as well.

Luke Hudson · 06-30-2003, 07:55 AM

ok, so maybe I'll keep it.

Out of interest does anyone know how to tell if it's working? Is the valve thermostatically controlled or just mechanical?

304065 · 06-30-2003, 10:18 AM

According to Roland Kunz, the factory determined that setup to be too restrictive for rally use, and the preferred mod was to saw the pipe about three inches out from where it attaches to the airbox. This also positions it right below the grille, for good cold air intake.

Early_S_Man · 10:06 AM

The device is purely mechanical and controlled by a bimetallic thermostat assembly ... and by 'ram air velocity' ... WOT is supposed to open the flapper and allow non-preheated air intake from the left-side nozzle/venturi intake ... rather than from the preheat air hose from the left-side heat exchanger.

Just remove the entire plastic nozzle/flapper/intake assembly with [3 ea M6 bolts, IIRC] and short rubber connecting piece ...

Seems that the rubber connecting tube can partly collapse at high RPM/vacuum levels, such as WOT operation!

You should also cap or plug the engine sheet metal where the hot-air hose formerly passed through ...