MFI Start Up With No Cold Start System
 

I’ve got a 2.3L MFI engine built with a 2.2S MFI system that’s in my ‘71E LWT street car. The only real modification to the MFI setup is the space cam has been profiled (by MFI Werks) to work with the slight displacement bump and the DC40 Mod-S cams. I’m also running a custom air cleaner arrangement that doesn’t have the cold start squirter system but the cold start thermostat / automatic warmup and warm air hose are connected.

I haven’t started the car yet but I’m concerned I’ll have issues getting it started on initial start and cold starting it.

For those with their cold start disconnected, do you have problems starting the car when it’s cold? From what I’ve read, it appears I may have problems getting the car to start quickly / easily with the system disconnected.

Would disconnecting the hot air hose / thermostat and installing a manual enrichment system help with cold start?

Would a high torque starter help since it spins the engine / MFI pump over faster?

Lots of questions but curious what others have encountered with removing the cold start from their cars.

Stretch

Lots of them have a faulty cold start system and they do start, just not as quickly. The cold start just squirts fuel down the stacks, and after it starts, that system doesn't matter anymore. The pump thermostat and it's warm air hose take over from there.

I have a setup similar to yours on my racecar. I actually went to the trouble of fashioning a nozzle to squirt the cold start into the stacks via the PMO filter housings. It worked fine, but it turns out that it's just as effective to push the accelerator to the floor during cranking, and it fires up after a few seconds every time (obviously be ready to let of the accelerator pedal once it fires to avoid overrevving). Once I realized this I ditched the cold start mechanism.

I use the Supertec enrichment device with a cable and it works well when you get the hang of it. It’s used in conjunction with hand throttle.

These cold start systems can be pretty faulty and often cause backfires due to squirting too much fuel. The temp sensors were not the greatest back in the day.
I hard wired mine to a button on the dash. I just press and hold it once for about 1 second and it fires up right away.

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Gents,

Thanks for the replies.

I was trying to avoid a cold start system all together so I’ll start with holding the pedal on the floor. If that doesn’t work well then I’ll look at other options.

Stretch

Mine will start after extended cranking with pedal to the floor, but starts much easier with a short press of the button similar to Winters above.

The foot to the floor procedure is good for hot starts, I would be reluctant to use it on cold starts.
What happens if you crank it a couple of times before pulling up the hand throttle and actually holding the key to start?
Do you have a hand throttle?

Used to have the MFI system on an E21 BMW I built, I had a cold start injector [into the inlet manifold] operated from a push button on the dashboard, just pressing the button with foot slightly on the throttle while the engine was cranking was easily enough to start it every time.SmileWavy

Lots of cranking w/o the cold start. Starts right up with it. Its exactly like a choke in what it does (not how it does it).

Chris
73 911 E