I have an 84 Z28. My care won't crank once the car is hot. I changed the terminal wires, the alternator, the starter, and the battery. The car originally had a 305, but now it has the Edelbrock performer RPM package on a 355. I have had this problem since I first bought the car with the 305. I have had 3 starters and 2 or 3 alternators and I think 2 batteries, 2 positive terminal wires, and one new negative terminal wire.... NOTHING!! I can't figure it out. The problem happens once the car is warn... around 180 degrees, and I have to wait till it cools a little to start it back up again. The timing is at 14 degrees... so it's not that. I had an electrician look at the car.. and he said that the starter motor seems to be "drawing" power. He said that that happens b/c it is becoming hot. I can understand that happening b/c of the headers I have on the 350, but the 305 was stock and I had the problem. I did find, though, that some of the wires coming from the starter were getting chewed up and grounding themselves. I fixed the wires, changed the starter, and still have the same problem. It's driving me NUTS! I even bought an external syllenoid for the starter, so now there is only 1 wire going to the starter... the fat terminal wire. Didn't do a thing. I put a cheesy heat shield on the starter syllenoid... didn't help. What else is there to do??? Any Ideas??

Thanks,
John

 

If you added a separate relay (some refer to this as a solenoid, but it is actually a relay - a solenoid moves the pinon gear to engage it with the ring gear teeth, and, in the case of a GM starter, the solenoid also acts as a relay to switch on power to the starter motor, once the pinon gear is engaged with the ring gear) in the "thick" battery wire path to the starter, did you connect the "S" terminal from the starter solenoid to the large terminal on the starter solenoid? In other words, is the purple wire now connected to the external relay (that you added) coil- Just curious on exactly how you have it hooked up.

It sounds like you have already changed out the large wires that carry current between the starter motor and the battery, so those are probably not the problem. Is the negative (black) wire ground point at the block a good connection?

Here's the current path from the battery to the solenoid "S" terminal (purple wire): The positive (red) battery cable feeds power to the large lug on the starter solenoid. One of the 3 fusible links connected to the large lug on the starter solenoid feed power to the ign switch through a red wire. From the ign switch, a yellow wire carries current to either the P/N switch (auto) or clutch switch (maunal), when the ign switch is in the start position. From the P/N switch or clutch switch, a purlple wire carries current to the starter solenoid, through the driver's side fire wall connector.

Try starting it in Neutral, if you have an auto, when the problem is occuring.

Check the voltage at the purple wire coming from the P/N (or clutch) switch, while the ign switch is in the start position, while the starter won't crank. The voltage should be around 12 volts. If it is low, the problem is up stream of that point - the P/N switch, the ign switch, or the fusible link (new fusible links are available from Pep Boys). If the voltage is OK, then the problem is down strean of that point - an open at some point in the purple wire, or the chassis connector terminals at the fire wall are coroded.

This may be difficult, but try measuring the voltage at the purple wire at the starter solenoid "S" terminal, when the problem is occuring. One way to do this is to crimp a ring terminal on to a wire & connect it to the "S" terminal on the starter solenoid along with the purple wire & route the new "sense" wire up to the engine compartment & measure the voltage a the end of that added wire - it's like adding a probe - since, when the engine is hot, it's difficult to clip a probe on the starter "S" terminal.

Any wire splicing you do should be soldered together, as just twisting wires together will corode, and be subject to vibration loosening, which may result in an intermittent connection, whose conduction may be subject to ambient temperature.

Tim

 

Just wanted to let you know that I am currently having the same problem with my car and have just purchased the remote solenoid (remote relay). I thought that by adding this remote solenoid my problem would go away. I have not installed the remote unit but your note got me thinking that it may not fix my problem.

Here is what I believe is causing my problem (and possibly yours). There is too much heat given off by the headers and the solenoid is getting way too hot.

I believe that when the solenoid gets to a certain temperature it looses the ability to function properly. Even if it has the full 12 voltage - which the remote solenoid setup should provide - the solenoid will not engage at all. If it won't pull back, then it will not push the pinion gear forward to the flywheel.

What I am planning on doing is wrapping the headers with thermal tape (Thermo Tec?). I have done this before on my vehicle and I never had any starter problems. A few years ago I pulled the motor out of my car and installed a more streetable motor and removed all of the thermal tape. Ever since I re-installed the stronger motor in my car (one that generates much more horsepower - and more heat) my starter began to act up.

Last weekend I wrapped the passenger side header and will finish off the rest of the job this weekend. I will also install the remote solenoid. Hopefully the problem will go away.

Please let us know if you have solved your problem?

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355 Dart 2 Heads, Victor Jr, Holley 750 Vac Sec, Engle Solid Cam, 350 THM 3000 Stall, B&M Megashifter, MSD Digital 6, 4" Mufflex, Spohn Torque Arm LCA Panhard Bar, Currie 9" 3.70