Need some help diagnose this starting problem please.

ajackson · 06-17-2004, 08:55 AM

Last night I drove my 3.2 about 45 mins to a class. After coming back to the car (had been sitting around 1.5 hours) the thing would not start. This is unusual because it has started up right away every time I have tried for the entire couple years I have owned the car. The battery was obviously fine, all my lights were on, dash gauges on fine, everything like that. When I turned the key, however, all I could hear was a high pitched buzzing sound. The engine didn't even try to turn over.

A couple friends pushed the motor, popped the clutch, started right up and I drove it the 45 mins home. After I got home, shut down the car and tried to start it. Started right up! Tried this morning, started right up. I am not a mechanic by any means but I have been doing a lot of DIY stuff lately with all of your help so if anyone has any suggestions please offer them. I know it is a pain when you can't reliably reproduce the problem...

The only other thing worth mentioning is last weekend I did an autocross and drove up to buttonwillow from san diego (no problems all weekend).

targa911man · targa911man's Garage

First thing to look at is the DME relay. Seeing as you have a conversion,, I don't know where it is on your car. On the Carerras, it is under the front seat next to the DME unit. It is about 1 1/2 " X 1 1/2" X 2" and is screwed to the floor. Just remonve the screw, disconnect it, and replace it with a new one. They are about $40. If I were you, I would go ahead and buy one, because they can go at anytime, and usually do at the worst times: on the track or in the middle of a long trip.
There is one thing you can try before switching the relay out. Turn the key to on but not to "start". Press about 1/2 way down on the accelerator and hold it for 13-15 seconds, then turn of the key, wait a few seconds, then try to start normally. This procedure can sometimes "reset" the DME. I have been ridiculed for suggesting this, but I read it somewhere a couple of years ago and have used it successfully several times in no-start situations.

ajackson · 06-17-2004, 10:23 AM

When I was turning the key, I actually heard something going. Hard to describe the sound, kindof like a whining sound. If the dme relay is bad, would it be doing even that?

Westy · 06-17-2004, 10:28 AM

Alan,,are you saying it sounds like the starter motor is turning, or is the whining like an electrical high pitch whine??

ajackson · 06-17-2004, 10:37 AM

To guess, I would say it sounds like the starter motor is turning.

ajackson · 06-17-2004, 10:38 AM

Something that may or may not be related, in willow springs I was having problems (after a few track sessions) with the car running, but the fuel cutting out. I would be driving and then the car would start stuttering as if I wasn't giving it gas. Basically, the accelerator pedal wasn't doing anything. If I pumped the gas, it kindof went, enough for me to get off the track. Started it up a couple hours later, and it worked fine, drove it the 2.5 hours home.

Someone suggested the head temp sensor (I guess mine isn't upgraded with two wires). Could they be related at all?

Westy · 06-17-2004, 10:43 AM

I have never looked at a P-car starter, but I will assume they are all the same basic design. The simple problem is the starter gear is not being pushed out because of a bad celenoid (how do you spell that?). Your celenoid can be bad or a wire corroded or broken. Sometimes if you hit them with a mallet or the like they can be jogged back into service. The bad problem is maybe one or several teeth on the starter gear have been broken off, but this is very unlikely. The worst case scenario is your flywheel has teeth chipped of of it and there is nothing for the starter gear to engage with. Push the car a foot or so with it in gear. If the starter then works, you have a bad flywheel.

Mt 70 Camaro had a bad flywheel, and I never replaced it. On those days it would't start, I just let it roll back a foot or so and it started everytime. Of course, I was a lazy SOB

Brian

targa911man · targa911man's Garage

The noise could be the fuel pump.

ajackson · 06-18-2004, 11:19 AM

I thought the fuel pump would come on when I just had the key set to "ON". If that is the case then it is something else because the sound only happens when I move the key to "START".

The problem is occuring again, so it is definatly something I need to fix. I'll try moving the car a foot while in gear first and if that doesn't do anything I'll take out the starter and bring it to autozone for testing.

Thanks for all your suggestions guys.

ajackson · 06-18-2004, 11:29 AM

What would the symptoms be if the dme relay was bad? I'll order one anyway, but would the starter motor be spinning when I turn the key (assuming that is what the sound I hear is).

I've found a lot of different guides for troubleshooting start problems, but a lot of them leave out diagnosing various symptoms and just give you a list of stuff to check.

rick-l · 06-18-2004, 12:07 PM

If you can push start the car there is nothing wrong with your DME relay. Concentrate your efforts in the area of the starter.

klaucke · 06-18-2004, 12:17 PM

Sounds to me like you have a gummed up starter. I've seen this many many times on lawn mowers and motorcycles. I'm assuming that the whine you hear is the starter motor spinning.

Now, normally, the inertia of the starter gear at rest causes it to move out towards the flywheel when the starter motor first starts spinning, until it moves as far as it can, which is when the starter gear is engaged with the flywheel. Until the starter gear slides across into position with the flywheel, the starter gear isn't spinning, only when it engages with the flywheel teeth. Now, if there is gunk in there on the starter shaft it could prevent the starter gear from sliding out to the flywheel. Then, when you turn the key, the motor just spins and never engages with the flywheel.

When I dropped my engine, the bell housing of my tranny had a ton of junk in it, so yours could possibly have the same after years of use. If the problem persists, I would remove the starter and clean it up, especially the shaft and starter gear, and make sure everything was moving freely. It would be a good time for new brushes while it was out too.

pauls81sc · 06-18-2004, 04:25 PM

I recently had a problem starting my 81. Car was making a high pitched whine with the key at start position, but was not cranking the engine.

Long story short....it turned out to be the tranny ground strap. Sprayed it with a little electical cleaner / degreaser and she started right up. May not be your problem but its worth the 2 minutes and $1.99 for the cleaner to try it.

ajackson · 06-18-2004, 07:44 PM

Can't find anything that looks like the ground strap in the pictures I have seen, where is it usually located? I did find this insulated piece of wire that might be it and has some pretty bad damage. Could this be a ground strap? I'll have to just pull it off and take it to home depot to find something like it.

I circled the end points and the arrow points to the damage.

ajackson · 06-18-2004, 08:30 PM

That last cable was at the back of the engine on the passenger side. These shots show something that looks like the transmission ground strap but one end goes behind stuff. This is in forward of the transmission (forward is towards the front of the car). Would I have to take out all the junk just to get to the other end?

I am assuming that the bar running across is the sway bar.

Also, I noticed the wire next to it is in bad condition, no idea what it is. It goes through a hold towards the front of the car. Any hints?

pauls81sc · 06-19-2004, 12:02 AM

That 1" wide braided wire in your last pic is the tranny ground strap.

All I did to diagnose my problem was spray it (soak it) with an aerosol can of electrical cleaner / degreaser.

I havnt replaced mine yet, but I agree it looks like all that stuff will have to come out to get to the tranny end of it. The other end comes off easily.

good luck