Help needed: car won't start

[Craig_D]

First let me introduce myself and say hello.

I'm Craig and I've been living in Boulder Colorado for just over 3 years and love it for the scenery, outdoors, and the incredible roads! I bought my first 911 in October and it's a 1978 SC 3.0 with all of the necessary updates: Carrera cam tensioners, Carrera fender well oil cooler, turbo tie rods, turbo valve covers.

This is my first post, and I wish it was about something positive (no pun intended). Here's where I could use some of your experience...I drove to the store this evening. Car took a long time to start...about 5-8 seconds turning over before it caught. It does that some time, even after a tune up and valve adjustment last month. Drove to my first stop...car started a little quicker from there. Then went to my second stop...took about 15 - 20 minutes to get my groceries.

Then went out to my car and turned the key and got only a faint hum from behind the gauge cluster. I flagged down a woman for a jump start from her pickup truck...still nothing when hooked up to her truck.

So I had to abandon my car and take the bus home and was planning on having it towed tomorrow morning to CarQuip, and good local Porsche parts/service center.

Any ideas?? Did I burn the starter out with that loong startup? I did check all of the fuses, they looked fine. The lights all light and she didn't start with a jump.

Any help would be greatly appreciated.

Cheers,

- Craig

[Nimble70]

Craig, did you check the battery posts for corrosion and cable tightness? You can get enough juice from your battery to run the lights and auxiliaries just fine with corroded terminals or loose cables but you won't be able to conduct enough current to spin the starter motor if this is the case. You should also have the garage check out the connections to the starter motor as well. Same thing there, corroded terminals or loose cable will not conduct enough juice to turn it over. The prolonged start really heats up the starter motor, and this heat could be the final straw that caused an iffy connection to finally give it up.

Good Luck!

Nimble70

[HarryD]

Welcome to our forum. You will find plenty of help here.

A few questions.

Did your car ever start easily on the first crank? or has it always been hard to start while you had it?

Did the starting problem start after the Tune up?

[Craig_D]

Thanks Nimble70,

I'll have to have CarQuip check the starter connections. I did check the battery and the cables/terminal connections were tight and it seems corrosion free.

I'm still at a loss..and hate the idea of my car in a parking lot all night..

[Craig_D]

Originally Posted by HarryD

Welcome to our forum. You will find plenty of help here.

A few questions.

Did your car ever start easily on the first crank? or has it always been hard to start while you had it?

Did the starting problem start after the Tune up?

When I got the car, it would occasionally take 5-10 seconds of cranking to start her. She'd almost start, then take a few more cycles to finally catch. Then the idle would hunt...or pulsate before warm where she'd idle fine.

After the tuneup she seemed to start quicker and the hunting cold idle went away, but now she occasionally takes a few more cranks than I like to get her started, and the hunting idle comes back one out of five or so starts..

[HarryD]

Originally Posted by Craig_D

When I got the car, it would occasionally take 5-10 seconds of cranking to start her. She'd almost start, then take a few more cycles to finally catch. Then the idle would hunt...or pulsate before warm where she'd idle fine.

After the tuneup she seemed to start quicker and the hunting cold idle went away, but now she occasionally takes a few more cranks than I like to get her started, and the hunting idle comes back one out of five or so starts..

Craig:

Hard to start - Sounds like your cold start system is not working properly. Check that all the parts are connected and functioning. Someone here has a similar car and hopefully can tell you what to check.

This may help as well:

Originally Posted by Walter_Middie

While the key is in the run position, power will be sent to the WUR if the Thermo-Time Switch allows it. On the left side chain cover is the Thermo-Time Switch which is the basic control for the enrichment solenoid during the starting phase. If the car is warm from running recently, or enough time has elapsed since it was started, the Thermo-Time Switch will interrupt the power going to the WUR.

The cold start valve itself has a grey and white wire and a red and black wire from the thermo-switch: Note that the gray and white wire and the yellow wire are connected to the same terminal on the thermo-switch. The WUR (warm up regulator) mounted on an intake runner base on the driver's side of the engine should have a single red wire with white stripes connected to it.

Cold start valve circuit: There should be a wire from the ignition switch to terminal 50 on the starter (this is a small blade type lug that receives a female type connector), from terminal 50 of the starter a wire (yellow) goes to the throttle valve switch. From the other side of the throttle valve switch a wire (also yellow) goes to the thermo-switch on the driver's side chain case, this wire from the throttle switch attaches to one terminal (this is the non-ground side terminal) of the thermo-switch, a second wire is also attached to this same terminal of the thermo-switch and goes to the cold start valve. From the other side (ground side) of the thermo-switch a second wire goes to the cold start valve.

Hunting at Idle-This is typically mixture related and is often traced to vacuum leaks in the fuel induction system. You can use carb cleaner (CAREFULLY) sprayed around the stuff that comprises the induction system and see if the idle changes. Typical places are the boots between the air box and the heads or a cracked air box. Also, if you have one, the flapper valve that may be present in your air box may be leaking. If you have NO vacuum leaks, you may have a mixture setting problem. Pay a few bucks and have a shop use their machine to set correctly.

[Craig_D]

Thank you for that detailed info Harry! That will help greatly when troubleshooting the inconsistent cold start and hunting idle issues.

From the description I gave, are there any guesses as to why the starter doesn't get triggered at this point?

Thanks, Craig

[HarryD]

Originally Posted by Craig_D

Thank you for that detailed info Harry! That will help greatly when troubleshooting the inconsistent cold start and hunting idle issues.

From the description I gave, are there any guesses as to why the starter doesn't get triggered at this point?

Thanks, Craig

Hard to say. Did you hear the starter solenoid click? Could be it overhetaed and is stuck. Try again after the starter cools.

A thought - check the posts by Grady and John Walker:

Stranded. Car won't start (it doesn't turn over)...

[Craig_D]

Thanks again Harry! That linked forum thread sounds like my problem. I went back this morning though and she still didn't want to crank the starter...so I had to call the flat bed.

I'll let you all know what it turns out to be.

Cheers,

- CraigD

[UrQuattro]

I had a very similar situation recently. I started up m. Car, drove to work, and when I got to the lot where I park, I shut it off. When the valet got in the car and tried to start it, nada. I jumped in the car in disbelief, turned the key, and heard what sounded like the click of a relay and the fuel pump started going, but nothing close to a real response from the starter.

I had it towed to my mechanic, but it was a Friday, and he didn't get it till late in the work day.

When he got it, they tried starting it and duplicated the problem. Then, when they came back after the weekend, they found that the car started..repeatedly. They tried at different intervals all day long, and he said that they must have started the car at least 50 times trying to duplicate the problem.

So, they went through the whole circuit and cleaned everything up, verified the grounds, etc.

I decided to go ahead and pick up the car as it appeared to be working now. The thought was that it was likely the starter, but that I probably still had some time left till it was done.

So, I picked it up, started it, drove to work and left it in the parking lot.

When I got off work, I paid the parking, for in the car, and..it wouldn't start. Same problem.

Fortunately, I had asked the valet to put it in a spot that we could push start it from jist in case.

Anyway, it ended up being the starter. I replaced it with a used one that I got off of the board here since i was short on cash and jist needed a temporary fix.

I dunno if this is helpful at all, but starters are funny things.

Michael

[Craig_D]

Thanks Michael, I'm leaning towards it being the starter now too.

I'll have CarQuip go through all the contacts first and then see about a new starter.

Any recommendations on lighter/better starters or is the stock starter the way to go?

- Craig

[UrQuattro]

Well, when the starter I got fails, I'm planning on going with one of the smaller high torque starters that our host sells.

Bosch rebuilt is high quality, but they are just that, rebuilt. The mini starters are brand new and from what I hear, they sound pretty cool.

So, that's what I'd recommend. They are jusr a little more expensive than the Bosch models. Here's the catalog page for you/
Porsche 911 & Carrera Switches & Motors - Page 1
On possible caveat is that I think a VERY slight modification to the flange on the starter needs to be made on some engines in order for it to seat properly. Still, even with that mod, i'd still go with the high torque one.

Michael

[Craig_D]

So it was the starter after all. I'm going to order one of the light weight high torque starters to replace the dead one.

Next step is working on that warm up regulator and getting the car to start and idle quickly/consistently.

Thanks for all the help and info guys!

Cheers,

- CraigD

[Craig_D]

Hey guys, I just wanted to thank you for the advice. It was the starter after all, and my shop replaced the dead one with an IMI Hi Torque unit they had in stock.

Man what a cool sound that little thing makes when you hit the key! Sounds like a pneumatic wrench mated with a small turbine engine! haha ...and best part is it starts the engine right quick!

Cheers,

- CraigD