SC Won't Start??
 

Yesterday I left the ignition in the "on" position and wore down the battery. Put a battery tender on the car over night and tried to start this morning and it just turned with no ignition. I usually starts on first turn so I knew immediately something was up. I did not hear the fuel pump so I thought it might be the fuel pump relay. I replaced the relay and the ignition switch started acting really weird - like turning over the engine before I turned the ignition all the way and making a very strange sound. Any ideas??

The ignition switch may be an entirely different issue but the pump relay replacement and the way it changed the switch start sequence was very odd.

Looking at the relay part numbers I replaced it with the wrong part # (911.615.109.01 vs 911.615.108.00).

Are you sure the battery is fully charged? Is it an optima battery by any chance.


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No optima - I've already experienced that! The battery is charged enough to start it.

Any other ideas?

what does charged enough to start it mean?

it can turn over but there may not be enough voltage to fire the CSV.

put a meter on the batt while cranking to check the voltage.

how old is the batt.

check fuse 18

My ignition switch is going bad and I am wondering if this would prevent the fuel pump from working? The car is getting no gas and before I dig into the pump I feel I should replace the key starter lock. Could this be the culprit?

if its an SC you wont hear the fuel pump when the ignition is on ,only if you are cranking, or if you have the fuel pump relay jumpered .
if you can turn over a starter motor there is more than enough electricity for other things, by far the biggest draw on a battery is the starter motor.
I am wondering if you have cooked your CDI box by leaving the ignition on and you no longer hear the whine from it with ignition on that you normally would.

to validate you had no fuel pump did you turn on the ignition then go around back take the air filter out and lift the air plate ? or did you just not hear the sound you normally do when you have the ignition on .

If your ignition switch is wonky it could definitely be that its not providing power to cdi box also.

The old adage of troubleshooting .. always fix what you can see, before fixing what you cant see. .....fix the ignition switch first because you KNOW that's an issue

Cdi...........
 

You could leave the CDI running for hours hours and not worry about it. The CDI would outlast a fully charged battery until the battery is totally drained of power. Have you ever experienced or heard a CDI going bad because the ignition switch was left @ ON position? Keep us posted.

Tony

Hi Tony I have heard of it but as always its third hand tribal knowledge . Ill see what I can find on the subject and post here if I find it.

+1

Put this variable (unknown) to bed.

Ordered the ignition switch and will provide an update after I replace. In teh meantime, what are the fuses to jump to check the fuel pump? I saw something about jumping 87 to 16 (or something similar) but what do those numbers refer to? I saw a photo in my searches and cannot find it anymore.

remove the connector on the top rear of the AFM and turn the key on, pump should run with engine off.
try to crank it.

Where do I find the AFM connector?

Lift the air plate with the key on and advise. Listen for fuel pump.

Slow down a little.

AFM sensor is on the rear of the AFM. It's just below the black rubber bellows. It's kind of hard to get to but not impossible.

You jumper the relay holes, not fuses. Edit: I will get you the socket hole numbers if you try the lifting trick.:D

do as above , you can check in literally 30 seconds, no running around looking for jumpers and sensors.

Those Ohio dudes just don't listen.

I bet the electronic part of the ignition switch is tits up, in the ditch.

yup ,

I lifted the air plate inside the air filter box and it made a sound - could be the fuel pump, except it was making more noise than I would expect from a fuel pump. What does that tell me?

That is the fuel pump and it sounds like it's working fine. Your issue is not the fuel pump i would think. .

Do you have a high pitched whine from the back of the car with the ignition on!? If not I'm thinking your cdi is shot or no power to it.

Maybe your ignition switch is not powering it

Check to see if you have Bosch cdi or permatune

Pull the main lead off the distributor and lie it close to a piece of metal and have a helper turn it over. See if you have spark.

I have the Bosch CDI and I do hear the high pitched whine with the ignition on. Checking on the spark ...

As promised. Key on. Jump with a wire in the fuel pump relay holes. Keep the relay on the bench. 30 and 87a. Terminal numbers are on the relay. Get your reading glasses.

Here is a good thread. Post #24 has a spiffy diagram.

http://forums.pelicanparts.com/porsche-911-technical-forum/673014-fuel-pump-relay-2.html

The sound or noise at the engine bay.........
 

Vance,

Let's do this step by step and help you understanding what is going. With the ignition off, there should be no noise/sound coming from the engine bay.

a). Turn the ignition switch @ ON position (not start). The FP should not be runing and if it does, this is not a normal condition. There is an electrical problem. Go to the engine engine area and listen carefully for any faint sound (high pitch tone). This faint sound should be coming from the driver side (engine bay) and that's the CDI.

b). Remove the air filter and lift up the AFS plate very briefly. The FP will be activated and the buzzing sound you will hear is the NOT THE FP. And if you could hear the FP noise from the rear of the car, you have a very sensitive hearing or the FP is noisy. The sound you are hearing is coming from the fuel injectors. People have inadvertently mistaken time and again about this noise. While it is true that the sound appears as you lift up sensor plate, what you could hear is sound of the fuel injectors delivering fuel unless your FP is making a very loud noise while running.

When I test the cold control pressure using the FP relay socket to activate the FP, I could hear the FP from the front and barely noticeable noise at the back of the car. I am not deaf or hearing impaired just old. Anywy, if you could hear the FP from the rear of the car good for you and be thankful.

Now, with the FP running and not injecting fuel (jumpering 87a & 30) lift the sensor plate and listen again. The noise you will be hearing is more noticeable because it is the fuel injectors delivering high pressured fuel into the combustion chambers. Keep us posted.

Tony

Definitely hear the CDI when the car is turned on. What exactly do I connect when jumpering 87a and 30?

No spark when I remove the main lead from the distributor?

If it turns out that this guy has another Bosch Silver Coil Made in Brazil we are going to have to do something about it :D

Pull the relay out of the socket, and look at the underside. You will see numbers next to each pin, molded into the plastic bottom. Note which pins are marked 87a and 30, and into which holes in the socket those pins seat. Using a piece of wire, jump between hole 30 and hole 87a of the socket. Once done, the fuel pump will run as soon as the ignition switch is turned ON.

Is your second comment a statement of fact--you do not have spark? If so, that should be your first area to resolve, IMO. Confirm good spark, then move on to fuel pump/pressure issues if things are not resolved. If you have an inductive timing light you can test for spark relatively easily.

No spark - at least when I pulled out the main distributor end of the coil wire and had it next to the manifold. Trying to confirm no spark but challenging one man job. Stay tuned.

Definitely no spark. Is it the Brazilian ignition coil? It is about 10 years old. $180 - WOW? The reviews do not look promising.

is your coil silver ?

if so you have found your problem I have a silver paperweight also. I went to a blaster coil and no issues . I got a used original as it looks better at a swap meet and now keep my blaster as a spare to loan to local friends when their Brazilian paper weight fails.

I think we have been saying that for what , about 10 years now ?? problem is I don't think they sell the Bosch reliable black one anymore

Did you go with the "MSD High Vibration Blaster Coil"? A third of the price is tough to pass up. Sure would like to drive it this week - looking if I can find it local.

Summit Racing has it in east Akron on the shelf but that is a jaunt from Cleveburg.

Just looked up the 3 on Advanced Auto's website. They offer them. Check Auto Zone as well. They are usually cheaper. May have to wait a day or so for delivery. However, my local Auto Zone has it in stock per the web site. High vibration coil as well.

The Blaster 3 accepts a different wire. Go with the high vibration coil.

yup that's what I used.
have you confirmed you had a silver one ?

some are waiting for coils , others are waiting for clutch cables ( me ) we all have our crosses to bare my friend.

Im doing dr. colour chip while I wait .

Mine is definitely silver but not sure it is the Brazilian made one. I found the MSD coil locally at Auto Zone and will have on Saturday. Thanks for your help guys!

Bob - We will need to connect one of these days. My wife is from Canton and I worked for Timken out of Engineering school. I will ping you one of these times when I come down and do the same if you come up North!

Had good luck with the Dr. Colour Chip!

yup if its silver , its Brazillian and dead ... I think it says made in Brazil right on it . We know those are terrible but it does bring us back to the original issue . Did leaving your ignition on kill the coil ? I wouldn't think so but the facts are in front of us.

Installed the new MSD ignition coil and id not start - UGH! Have not had much time to test it further but looks like it is not the coil. What do you recommend next?

I have the ignition switch on order and that is next but anything you recommend trying in the meantime?

Inductive timing light........
 

Vance,

Install an inductive timing light and crank the engine. If you don't see any ignition signal while cranking, you will NEVER EVER be able to get the motor to run. Confirm this and keep us posted.

Tony

I used an in-line light to check if I am getting a spark and nothing. That rules out the ignition coil as teh culprit. Hope to get the ignition switch changed over the next week. In the meantime anything else I should check?

Clarification.........
 

Vance,

I am little bit confused with your post above (first sentence). You were getting "nothing" and you ruled out the coil as a culprit? If there was no ignition signal, how would expect to get combustion? Maybe I am reading it differently. Thanks.

Tony