911 Starting Procedure and Fuel Microswitch

[larry47us]

Kermit runs fine when he is warm, but even though I have had the MFI adjusted and fiddled with, I am still having a hard time starting him. I was reading through the Factory Service Manual, and read a section on Hard Starting.

Well, the answer was that I wasn't starting the car according to the recommended procedure. This afternoon, we went for a ride - the weather was great, top off, sun on full. This is the first time that I haven't had a hard time starting when cold, or when warm.

So I have scanned the procedure out of the manual, and I present it here.

Also, there is a microswitch on the MFI that shuts off the fuel flow when the throttle is moved to idle (like when you are shifting, or when you are slowing down to a stop). This stops backfiring, and additional fuel from needlessly flowing into the cylinders. I found out that my microswitch isn't working. So, I need to get another one.

I am posting this so that those unfamiliar with this switch can find out about it, and so that someone can tell me where I can find one of these elusive puppies.

thanks

larry

[pwd72s]

When in doo-doo, read instructions? I hope the microswitch is still available, I've never replaced mine. Larry, I'm finding that Stoddard's may be a bit $pendy, but they are often a source of help for hard-to-find items. More so, than (I can say this here? Yeah...I'm on the S registry board.) Pelican.

[Zeke]

Did you test the switch independently? Also, can you hear it click when the motor is off and things are quiet? Sometimes the throttle springs aren't enough to push the switch closed. All adjustments have to be spot on and the push/pull rods have to be tight or there is enough play to allow the switch to remain open. An added spring can be a fix; just looks unsightly.

If you think any of this might be the case, put an 8 to 10" soft spring from the bell crank to the rear body latch member and drive the car.

[Shuie]

So the car is only hard to start when cold? How hard? How long do you have to let it crank before it fires up? I dont mean to sound like Yogi Bera, but if a MFI car is hard to start when its cold, then something is wrong with the cold start system.

My '72 needed to be cranked for 30-60 second continuously when the cold start system was disabled. as soon as it was hooked back up and eveyrthing was sorted, the car would start almost immediately.

Check the fuses in the relay panel. I think the middle fuse will run the CS solenoid on your car. Get a meter and find 12 volts on the relay panel. Wire a pushbutton to CS solenoid, hook up a long piece of hose to a bucket and test it. Make sure all of the CS lines are in decent condition as well!

There are no instructions for things like this. Only old posts from guys like Zeke and Grady Clay over at Pelican.

[larry47us]

When in doo-doo, read instructions?

Paul:

OK, I am guilty as charged. But who would think that there is a special procedure to start a car?? I know that Porsches were special, but I never anticipated this. So, I put it here for the others, like me who choose not to RTFM.

Go on, tell me that you knew that this was the procedure to start your car.

larry

[larry47us]

Zeke, while the engine was running, I ran the throttle up to about 3,000 RPM and then pushed the micro-switch. Nothing happened. According to the trouble shooting, doing this should cause the RPM to drop to 1,300. I will pull the switch and put an Ohmmeter on it. That should tell me.

Shuie: No, the car has been hard to start all the time, whether warm or cold. When cold, it stops 3 or 4 times before it would stay running. When warm, it would crank for 30 seconds before finally catching. But now that I know "the procedure" it worked fine for me today. Both cold and hot.

larry

[gulf908]

Larry,Zeke & the mfi experts,

I read the first remedy with a bit of concern.
If I understand it correctly, should it be ok to rev the cold motor 4500 even for a short time before the oil hasn't even woken up ?
Apart from this concept,I have to consider my half deaf ancient neighbors with the racket - maybe I should trade them in on a new set !
My previous car,a 1975 Carrera with a 2.7 RS motor started after 3 cranks and I re-set the hand throttle to 1500 rpm - perfect !
Am I missing something here ?

Cheers,
Dennis.

[platas]

Larry, i read this on a porsche manual some where, and i usually do this to start mine and the proce works very good, 80% of the time at least, but now i am incountered with a dilema.
I have left in the states three 911, in storage, coverded and the whole bit, but they have not been started for 7 months, going on 8, what would be the first thing to do ,besides batteries, the things to check to stat them, i do not want too just hop in and go, wich it would be great . This is the first time i leave my cars so unattended fo so long, any suggestions!

Thank you
santiago

[Zeke]

Zeke, while the engine was running, I ran the throttle up to about 3,000 RPM and then pushed the micro-switch. Nothing happened. According to the trouble shooting, doing this should cause the RPM to drop to 1,300. I will pull the switch and put an Ohmmeter on it. That should tell me.

Shuie: No, the car has been hard to start all the time, whether warm or cold. When cold, it stops 3 or 4 times before it would stay running. When warm, it would crank for 30 seconds before finally catching. But now that I know "the procedure" it worked fine for me today. Both cold and hot.

larry

Well, you are right that something should happen when you activate the switch @ 3000. If you have the CMA, you are in good hands, or should I say, your good hands will find the problem.

Yes, it is the middle fuse of the 3.

To start a car after 8 months, I wouldn't necessarily do anything special. Others may disagree, but that isn't such a long time that gas will necessarily be bad, etc. Athough, the battery might be dead. I'd plan on taking a fresh battery. Having the alternator charge the battery after jumping the car is over-working it.

[larry47us]

Santiago:

I haven't had that much experience with these cars yet. This is my first. This last winter was the first winter I "put it in storage." There are a variety of threads on this, and I have read threads where the procedure to get it "ready for winter storage" was at least two days worth of work for me. Too much.

I stored my car in an unheated attached garage from the beginning of November till the beginning of April. So, between 5 and 6 months. I had put Sta-Bil, a gasoline stabilizer, in a full tank of gas before I turned it off, and ran it for a bit to make sure that the MFI pump and injectors were filled with the Stabilized Gas. Then with the engine hot, I pulled the breather cap off the oil filler. I left it off till the engine cooled, to allow water vapor to escape. Then I plugged in my battery charger, set it for trickle, and left it for the period.

This spring, I took a deep breath, and started it. It cranked a bit longer than usual, and then fired up. No harm, no foul. I don't know how this helps you, but I wouldn't think that leaving the cars for one month longer than I did would create any larger problem, except for a dead battery, and little critters that may have taken up house. I'm not familiar enough with gasoline to know if that could be problematic or not after these months. But my cans of gas have sat all winter in my garage over the years with no stabilizer, and my mowers have lasted 15 years or so.

larry