No start problem after starter stayed engaged.

[dmarv]

Here is a short story of my problem. My mother-in-law was in a panic and needed a car to get somewhere. My wife let her mother take my 76 911S as it was the only car available at the time (I wasn't around). What my wife failed to mention to my mother-in-law was that the ignition switch needed to be changed and would remain in the start position and need to be manually moved to the run position after the engine started. My mother-in-law got to her destination without incident, but on her return trip the car died and could not be restarted.

I pushed the car to my house, as it died 1/8 of a mile from my house. The starter would not turn over. I replaced the ignition switch and the starter. Now, the starter only intermittently turns the engine over, not every time, the switch is in the start position. I can hear the solenoid click every time the switch is in the start position. I have tested the voltage on the yellow wire from the ignition switch and get 12V every time the switch is in the start position. It is seems as though there are not enough amps to always engage the starter. The times that the engine does turns over, it will not start up. I hear the fuel pump running and the CD box whine, but the engine will not stay fired up. I do see exhaust coming out the tail pipe as the engine is turning over.

I plan on checking the yellow wire all the way from the starter to the ignition switch tonight. I believe something got fried while the starter was engaged, but I'm not sure what. What else should I be checking?

[ossiblue]

It sounds like you may have two separate issues, one with the starter and another with the engine not running.

If you are getting a "click" with every turn of the key and the voltage is always 12 v, then I'd say the yellow wire and ignition switch are good. The click is the starter solenoid engaging and that tells you the yellow wire is doing its job. Once the solenoid engages, the high amp voltage from the heavy cable on the starter should come into play--this is where the problem may lie. Could be a bad connection at the starter, your battery may be weak, the solenoid is bad, or the starter is bad (new or rebuilt units have been known to be faulty right out of the box.)

If the engine doesn't stay running, you could have an ignition problem or, again, a too weak battery. Check your spark and check your battery. With both situations happening at the same time, the battery or connections to it are highly suspect.

[Targalid]

Everything Ossie said plus check the grounds and the battery cable connections. There is a flat braided copper ground strap which connects the transmission to the body. Remove each end, sand the ends of the strap and the body/tranny connection points. Reconnect using dielectric grease to prevent future corrosion. Also do the same for the ground cable at the battery, both the battery end and where it bolts to the body. The grounds must be clean to carry the full amperage needed by the starter.

[dmarv]

Thanks for the input. All grounds have been cleaned and I used dielectric grease on the contact areas to insure no corrosion will occur. Positive cable ends have been cleaned, no corrosion was visible before I cleaned them. I'll double check the positive end at the battery to make sure I have good contact between the cable and the battery end. I do believe that there are two different issues. My goal is to eliminate the starting issue first.

[wwest]

The only time I know of this happening resulted in lots of insulation burned here and there off of the positive side cable from the battery to the starter solenoid.

I surmised that the starter acted as a non-regulated permanent magnet generator and forced TONS of charge current into the battery.

[dmarv]

wwest,

I agree with you about the starter. The ends of the positive cable look fine, but there is a lot of the cable that is hidden. I may have to pull the cable and look at it.

[dicklague]

I feel for you......

Exeter CA? Do you know my friends at CB performance over in Farmersville? I was friends with Bob and know Pat and Rick,

[dmarv]

Originally Posted by dicklague

I feel for you......

Exeter CA? Do you know my friends at CB performance over in Farmersville? I was friends with Bob and know Pat and Rick,

Sure do, before the Porsche I had Type 1 VW's. CB got a lot of my paychecks when I was younger.