924S Intermittent Start Issue

apexeric · 07-21-2007, 08:42 AM

My son has a '88 924S Special Edition. The car has been having an intermittent start issue. Sometimes we turn the key and the engine will fire up immediatly.

Sometimes we will turn the key and the solenoid will click but the starter will not engage. We will turn the key several more times and then the starter will engage and the engine will fire.

We thought the problem must be the starter/solenoind. So we replaced the starter/solenoid. We turned the key and the car fired right up.

My son then drove to a destination not too far away and let the car sit for a few hours. When he tried to start the car again the same condition occured. After about 15 key turning attemps the starter engaged and the engine fired.

I can't say that this is a temperature related issue because the same condition has occured after the car was parked over night.

Just for the heck of it we took the old starter and hooked directly to a 12 volt battery. The solenoid gear seemed to engage and the starter spun under load properly.

If the key switch was involved would the solenoind click every time the key made contact?

Any relays that we should be checking?

Thank you.

Eric

John_AZ · 07-21-2007, 09:25 AM

Welcome and let me be the first to offer: Check the batt for full charge, or ground strap to bell housing. Clean connection at bell housing, very hard to get at with big fingers. Oder, DME/fuel pump relay. I carry a spare. Tap the relay under dash sometimes this may temp fix.
Good luck.

John_AZ
1988 924S
1987 924S

apexeric · 07-21-2007, 09:46 AM

Thanks John AZ,

The battery has a full charge. We will recheck the ground strap connection.

How does the DME relay affect the performance of the engine?

Tap the relay under the dash? Is that the DME relay? Where is it located?

Thank you,

Eric

John_AZ · 07-21-2007, 12:31 PM

DME/fuel pump relay is #II

OR...does your 924S have an alarm system? Mine came with dealer/factory unit and occasionally I have to wiggle the security plug.

John_AZ

apexeric · 07-21-2007, 01:21 PM

Hmmmm, our car came with an after market alarm that we "think" we have disconnected.

I am thinking that this is more of a connectivity issue. When the key switch is turned there is a solid sounding click/ckunk to the solinoid. It seems as though it takes several attempts, sometimes 15 attempts, to get the solinoid to egage the starter.

I'm trying to interpret the weather conditions as one of the factors as well. The car started perfetly yesterday afternoon - warm, sunny, no humidity. Last night was cool and the dew had fallen and difficult starting. This morning the car started right up at 11:00am - son sleeping in - sunny, warm, no humidity. I am wondering if the weather conditions will affect the ground connections?

Thoughts?

Eric

John_AZ · 07-21-2007, 02:23 PM

It could be a Harry Potter thing.
John_AZ

apexeric · 07-21-2007, 02:45 PM

It could be...my son's name is Harry!

Eric

zedsn · 07-21-2007, 03:18 PM

Hi, did you replace the starter with a rebuilt one or a used one? If used maybe it only works when it wants to. Did you clean your positive and negative cable on both ends? Maybe you might need a new positive cable if your starter load tests ok. I would also check your starter switch wire for corrosion or a messed up connector.

blown 944 · 07-21-2007, 03:36 PM

I would look at the ignition switch it can make part contact intermitantly and also it can do this more severly when it is hot in the interior.

onZedge · 05:00 PM

If both starters pulled in the solenoid but didn't turn the starter motor, you likely have a power cable problem. Keep in mind that your battery cables are almost 20 years old. Unlikely to have two bad starters in a row, but it could happen. Easy stuff first. Read the voltage at the big cable on the starter and at the battery. They should be exactly the same. If not, you have a bad positive cable. If OK, disconnect the battery ground and, using an ohmmeter, check the resistance between the negative battery cable clamp and the frame of the starter. Should be nearly zero ohms (<0.1 ohms). If not, you have either a bad negative cable or a poor ground connection at the top of the bell housing where the negative cable connects to. As always, make sure your electrical connections are clean, dry and shiny before reassembly. Dirty grounds can cause all kinds of problems on a 20 year old car. Find them all and clean them. There are about a dozen throughout these cars.

onZedge · 07-21-2007, 05:03 PM

I just noticed it is a '88 924SE. Kind of rare. Got pictures?

apexeric · 07-21-2007, 05:06 PM

I've considered the ignition switch and was planning to spray contact cleaner into it. But I'm still sure that the solenoid is receiving full power because it makes a loud click/clunk when the key switch is turned. It just seems to take a few attempts to make it work.

We replaced the old starter with a rebuilt Bosch starter (ordered from Pelican Parts!!) so I am assuming that the solenoid is in good working condition.

Thank you for all of the replys so far.

Eric

onZedge · 07-21-2007, 05:13 PM

I really don't think it's the ignition switch. It doesn't take much to pull in the solenoid, but the starter doesn't like to turn at low voltages. Please humor me and try what I suggested. After all, you came here looking for help, didn't you?

apexeric · 07-21-2007, 05:16 PM

Quote:

Originally posted by onZedge
I just noticed it is a '88 924SE. Kind of rare. Got pictures?

Thanks for that advise. I will folllow the steps in your post tomorrow.

As for the 924S, my oldest son owns a 924S SE and my younger son owns one also. They happen to be 222 serial numbers away.

We are trying to sort the starting issue out for my younger son's car.

I have some photos. More of a group photo. The 968 is mine.

apexeric · 07-21-2007, 05:20 PM

apexeric · 07-21-2007, 05:23 PM

John_AZ · 07-22-2007, 05:21 AM

What, no Porsche Cayenne turbo for your au pair? I suggest an old school test, get a remote starter switch and see if the problem stops. Nice.
John_AZ

apexeric · 07-22-2007, 09:09 AM

You know, I thought the whole Porsche thing for the children might be over the top. But is not. These 924S's and 944's are a great value if purchased properly. Since they really only have two seats I don't have to worry about a car full of kids cruising around doing who knows what. Many of their freinds have Subaru's, Toyota's and Honda's that will smoke a 924S of the line. I've tried to teach my kids to save the fast driving for autocross or driver's education. The insurance rates are high for these cars but not as high as the rate for a Subaru Impressa for instance. Plus my boy's really appreciate these cars and the engineering that goes into them.

As for the au pair - if I could afford the au pair then there would be a Cayman S or GT3 parked between those two 924S's!!! LOL

The romote starter switch is an excellent idea and I will be checking the voltage and resistance at work tomorrow.

Thank you for all of the advise and guidance up to this point. I will report back as soon as I sort out this issue.

Eric