Trouble starting, but not running!

[Turbo301]

Hi all,

My '91 runs like a top, for long distances and durations, but will only start a certain number of times (after being shut-off and re-started, at any interval) before it chugs, chugs, nothing. I cleaned-off the positive battery terminal and charged-up the battery, and it was working great after that for a few starts; however, I hear it starting to get a bit chuggy again, suggesting that charging the battery may have masked another problem.

In light of these issues and the fact that the car runs fine when up-and-running, I'm assuming that the alternator is not charging the battery but is supplying all of the car's circuitry just fine when running. What would cause this?

The battery is only a few years old and the car is stored inside, with a tender on it during the winter.

Thanks to all for your help!

[FordMan77]

Time to break out the multimeter and measure voltages. You should be able to put your positive lead on the charge cable on the alt and then ground to the case to see what the alt is putting out while running. Also test at the battery terminals with the car off and also running. Could be the alt not keeping up. May also want to check ALL the grounds on the car as well to make sure they are clean and tight.

[friskyfrankie]

Yep - wiring (grounds) and alternator production would be the first few things to check.

[87GrandMarq]

Could also be the starter heat soaking causing a slow crank. It’s a common issue. Is the starter original?

[Turbo301]

Hi all! So I think the starter is indeed the issue (I came to that conclusion even before seeing 87GrandMarq's comment, but good to know it's a known issue). I don't know if the starter is original, but it's definitely older than my having bought the car. I've never felt an engine bay as hot as this car (including that of my brother's turbo T/A!), so it could be heat soak or just heat degradation. Honestly, I don't know what goes on under the hood of these things, but dat heat!!!

The output from the alternator is good, the battery is good, but the starting is inconsistent: yesterday it was pretty sluggish until it wouldn't start at all. Key off, try again, and it sprang to life. So, maybe dirty brushes or slip rings or something. I'll see if I can clean it up.

Does anyone have the P/N handy so I can be sure I get the right starter when I look for a replacement?

[friskyfrankie]

Can always check with RockAuto, at least for a part number.

[Turbo301]

Yeah, they're not always correct (twice I've gotten the wrong brake calipers for my Elantras from RA), but I've correlated their results with Amazon and they seem to agree, so that's something .

[friskyfrankie]

ALWAYS double check part numbers no matter where you find them.

[87GrandMarq]

I would get a high torque mini starter from LMR. They’re less prone to heat soak.

[gadget73]

91 should have that already.

for what it may or may not be worth, I've never heat soaked either style of starter on a panther. They can get weak over time though. I had what I thought was a dying starter on my S10, turned out to be the starter-mounted solenoid dropping too much voltage. The practical fix there is a new starter because those are on the shelf and a solenoid is not but it had the same slow-crank issue either way. The later Ford starters are the same basic design as the Chevy ones with the solenoid mounted to the side of the starter.

[sly]

I've heat soaked the solenoid on the OE starter on my 93. The one on the 88 MGM I used to have stopped throwing/pushing out the engagement gear. I have yet to have the actual starter motor have issues in any of my vehicles. I know plenty of people who have had starter motor issues though. I've helped replace a few of those.

[Turbo301]

Whether due to heat soak or just old age, it was indeed the starter: I put in a a remanufactured Motorcraft and she's been perfect since. I can't tell if the one that came off is original or not, but it was definitely old .

Thanks to all for the help!