Wrenching Mistakes Are Guaranteed. What You Do with Them Is Not
This story first appeared in the November/December 2024 issue of Hagerty Drivers Club magazine. Join the club to receive our award-winning magazine and enjoy insider access to automotive events, discounts, roadside assistance, and more.
I’ve owned something like 100 cars and have been wrenching for nearly 50 years. I like to think I have a good bead on the diagnose-repair process. I do, however, occasionally mess up. Below are three instances where I flat-out got it wrong, and what I learned.
The Bad Battery
One of my cars had developed a hard-starting problem characterized by slow cranking. The car typically sits in remote storage with the battery disconnected for months at a time. I recharged the battery, which was going on seven years old, but the problem remained. My handheld digital battery tester reported no issues, but given that the tool was itself 10 years old, I assumed it, too, had died. I could have tried the battery in another one of my cars but decided my aching back didn’t need that. So I bought a new battery. No reason to overthink it, right? Wrong. I dropped it in, and exactly the same thing happened. The problem turned out to be the starter motor.
Lessons: Overrule test equipment at your peril. And just because you don’t want to do work doesn’t mean it isn’t worth doing.
The Red Herring Starter
I was road-tripping with some folks when the points in the distributor of one fellow’s BMW 2002 closed up. This is very common, but what was unusual was that when I’d reset the gap, the problem would recur half a day later. And oddly, wherever we stopped, there seemed to be a foul smell—somewhere between propane and sewage. On the last day of the trip, his starter solenoid clicked but the engine wouldn’t crank at all. I checked the resting battery voltage, and it certainly wasn’t discharged; if anything, at 13.1 volts instead of the usual 12.6, it was a little high. I ran a wire directly from the battery to the solenoid. No difference. Given my recent experience misdiagnosing a bad starter as a bad battery, we procured a replacement starter. I installed it in a parking lot—and was stunned that it made no difference. Puzzled, I jumped his car with my own, and it cranked and started with no trouble. Conclusion? There was never anything wrong with the starter. He had a bad voltage regulator that had killed his battery by overcharging it and was pitting his points, causing them to close up. Had I followed my nose, I’d have figured it out sooner—a rotten-eggs smell is a textbook sign of an overcharged battery. A basic charging system test would also have clued me in.
Lessons: Don’t let your last blown diagnosis unduly influence your current one.
The Dizzy Distributor
I’d sent the distributor from my BMW 2002 off to be rebuilt. When it came back, I outfitted it with the proper new Bosch points, condenser, cap, and rotor. On the car’s test drive, it began running so horribly that I barely made it home. A professional wrench friend came over in his own 2002 to help. He yanked the distributor from his car and said, “I just drove over here, so this one’s known-good. Let’s drop it in your car.” I protested. Everything in my dizzy was new. It was the “known-good” one, not his. He mock-barked at me, “ARE YOU HAVING A PROBLEM OR AREN’T YOU?” He installed his tired-looking distributor in my car, and to my astonishment, my car ran like a sewing machine. “Now,” he said, “We’ll transfer over one component at a time to find the bad one.” Turns out, the brand-new Bosch condenser in a BMW box with a BMW part number was to blame.
Lessons: There is no “known-good”—there are only symptoms. Whenever you say, “It’s not that,” a red flag should go up, because you just admitted you have a blind spot around “that.” Also: Listen to professionals.
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Rob’s latest book, The Best Of The Hack Mechanic™: 35 years of hacks, kluges, and assorted automotive mayhem, is available on Amazon here. His other seven books are available here on Amazon, or you can order personally inscribed copies from Rob’s website, www.robsiegel.com.
Sadly today many parts are listed by the MFG as to test with known good part.
Even the automakers are to the point where some items you have to throw parts at them as there is no testing of the part available.
The following is going down a rabbit-hole probably no one is interested in pursuing, since it doesn’t relate to a car that was running fine, and then decides to quit, for no apparent reason.
It’s a process of elimination, right? I mean, assuming fuel is relatively fresh, fuel lines aren’t blocked or pinched, the fuel pump and filter are good, and nothing is blocking/choking intake/exhaust airflow.
If I’m committed to reviving any unknown old gasoline engine that “won’t start”, I tend to chase ‘starting issues’ by beginning with relatively inexpensive, low-hanging fruit. Let me know if I’m missing anything!
Since EVERYTHING is known to be old, the electrical process of elimination begins with:
0.) before anything else, drain the ancient, black crude, looking for coolant, refill if none, and attempt to spin the engine manually (easier with the spark plugs removed),
1.) check the condition of the points, and replace if not near-perfect (replace as well, the condenser, just for good measure),
2.) clean electrical connections, at the battery and any primary remote grounds,
3.) examine the old cable(s) for internal corrosion hidden by the pvc jacket. If at all suspect: always replace, and examine the fusible link, if equipped,
4.) typically replace the old battery (I always suspect any older than 3 years for ‘recent’ lead-acid batteries),
5.) replace the coil if the spark flash is weak,
6.) just for fun, clean and gap the plugs and examine the cable terminals, and distributor cap for corrosion (and clean the internal posts). Replace the cap, rotor, and cables if very old or moisture exists, and check for a bright flash at each spark plug electrode,
7.) replace the independent starter relay/solenoid, if equipped (i.e. Ford),
8.) bench-test the starter itself to observe proper operation, and examine the pinion for damage (as well as ALL the ring gear teeth).
At this point, a timing issue would likely prevent the engine from running.
If the flywheel (or torque-converter) ring gear is good, the most expensive parts involved are likely the battery and starter itself, but if you’re committed to driving this thing with confidence, don’t wait until they’re completely dead, plus, you’ll have an old starter to learn the skill of rebuilding, which will come in handy when the new “known good” starter goes bad.
Good advice Mikey, as a farm boy I have been interested in mechanical things from a young age. I pride myself in being able to find and fix the problem. (I’m now 81 but still wrenching) What do they say, pride goes before the fall, or something like that. My wife purchased a 1976 Cougar XR7 460 CID, barn find, of course who gets to make it run? yup me! It would kick back so bad when cranking that you thought the starter would break! I did it all, starting with timing, battery cables, stater, cranking voltage to the coil and on and on. Lots of time online, be careful of that advice. Some of those posts are from guys just wanting to type words, no good advice! I replace the ignition module and dist pickup, they were new when we got the car, should have known! The engine has 107000 miles on it, so replaced timing chain and gears. After countless hours it was the same, NO different. As it turned out the cheap aftermarket module lacked the timing retard circuit, so it kicked back. One HEI dist later and base timing @ 12* cranks fine. Cheap is not always a good idea, OEM should be the way to go.
I’m sure there are many stories just like mine.
Thans for reading.
Dave
Car needs 3 things to run – spark, fuel, and compression.
To get compression it has to spin.
Step one, hand turn engine. If it turns remove plugs and put oil in cyls
Not siezed? check/verify battery, disconnect fuel supply and attempt to crank.
If no crank eliminate starter switch/neutral/clutch switch etc by bypassing solenoid and using known good booster. If it cranks work back the circuit to find the bad switch/wire.
If it cranks, check compression. Check oil pressure.
If compression is good check for spark. If no spark investigate. If spark give it some fuel in the intake and attempt to start. If it starts check fuel supply – if dark or stinky gas drain and flush and replace filters – check fuel pressure.
No use replacing a bunch of parts then finding it is junk because it has no compression or a spun main bearing or???
If it starts and runs, THEN go over it and give it a good tune up / oil and fluid change
I swapped the stock 4 cylinder in my 80 MGB with a freshly overhauled Rover 3500, new carb, new Mallory points distributor, new leads and caps, spark plugs and all. Got it all together and it started first try and ran great, problem was it would not restart if it was hot. I could start it cold and drive till it ran out of gas but if I shut it off and tried to restart while hot it would not go. I adjusted timing, checked compression, checked for air leaks, took the carb apart, even checked the cam operation to no avail, it would not start when hot. While doing some tests I noticed the new spark plugs were resistor plugs with 5K resistance so i thought maybe try a different plug so I installed a set of non resistor plugs and the engine would start when hot but was still a bit hesitant. Then I looked at the new, best I could get, ignition leads and plug caps and the caps were also resistor caps with another 5K ohms, so I had 10K ohms resistance at the plug end and apparently that was just too much for a hot start. I changed it out to 0ohm caps and the engine started fine hot or cold. This was a new one on me.
Wrenching keeps you humble – you’ll fix many wrong things before getting to the right one.
The condenser problem was the exact thing that happened to me. I had the distributor curved by a speed shop and they put new points and condenser in it, well it ran great until the engine bay got hot then the engine ran like crap. I had to have my 327 66 corvette towed home one time because it wouldn’t restart. Well after rebuilding the carb, changing the coil, etc., etc. I read an article about testing the condenser with a multimeter and that is what it was. Moral of the story, new parts can be bad.
An erratic spark as the engine warms up is usually the condenser .
Please detail how to test using a multi meter ~ I have a nice one I don’t want to fry .
TIA,
-Nate
(who also ass-U-me’d the ten year old red top 6 volt Optima battery had failed so now I have two……)
BMW. ‘Nuff said,
Points. I was taught that if you have big build up on the points change the condenser and the points. If the points have worn evenly, you have a good match, change the points only. However, if you can drop in a Pertronix in your distributor, no more of that points nonsense, and you start and run better.
Word of caution! Pertronix ignition modules are good when new, but have problems as they get older. In my 50+ years of professional wrenching, and using Pertronix, I finally found the M&H Breakerless Ignition modules 30 years ago. I have installed 100+ units. They are virtually flawless, with only 3 failures that were fully warrantied.
I have never, EVER had one fail but then I’m stupid and follow the instructions, they specify the coil’s impedance and no, they’re _not_ all the same, either 6 (1.6 Ohm) or 12 (3 Ohm) .
-Nate
One thing I’d add about batteries…in arizona as ‘winter visitors’ leaving a car in the garage for the summer, batteries only last a couple of years because of the heat. and no, bringing them in the house doesn’t help much either if you leave the AC set at 90! Just one of the additional costs of avoiding a long winter up north!
I replaced the 6 Pack on my 340 Swinger last August. The Carter avs carb. and original intake manifold worked perfectly ,for 2 weeks . Week 3 ,I took the car for a short drive on a Sunday morning. After driving about a quarter of a mile ,the car suddenly shut off. Pulled over ,popped the hood ,fuel spilling from carb. Figured it was a speck of dirt on needle valve. Dissassembled new carb. checked very carefully for small specks . None Float had sunk in bowl due to the solder flux dissolveing from a poor solder joint on float. It took 2 dissasembly,s to dis cover problem. Lesson; Never assume a new part will always cure a problem.
Now 78 plus and still helping neighbors with auto problems. Mostly battery issues. My personal FJ Cruiser is garage kept, Florida based, almost 11 years old with 12,600 miles. I’ve had a battery tender on the original battery since new. Still shows 12.6 volts. Charger is 1.25 amps. Drive it to car shows periodically. My experience is that two things kill batteries: lack of use and heat. My company cars batteries rarely lasted 2 years because I sat on the side of the road using my cell phone with the engine running. Later models lasted longer when Ford put an insulating blanket around the battery. My neighbors 2019 Jeep with 19,000 miles just needed both the main battery and the ESS battery replaced. $630. It’s a weekend machine that they use to go to the beach. A medical situation didn’t allow them to use the jeep for about 2 months. Both batteries dead. No battery charger use. I believe the battery charger(maintainer or float charger) allows the electrons to flow between the anodes and cathodes to keep them from crusting over and shortening the battery’s life. I’m hoping my Toyota Battery, a Panasonic I’m told, will last a couple more years. My John Deere Tractor, my dune buggy and my Can Am Spyder as well as my electric start Honda generator all have Battery Tenders on them. At under $50 much cheaper than a new battery every few years.
All so very true ! .
Back when I was daily driving an ‘A’ Model Ford to work I did a tune up using Motocraft parts (yes, Ford still makes and sells various ‘A’ & ‘B’ Model parts) I developed and erratic hot miss, the brandy new condenser was kaput .
Using the old tech skills I learned in the 1960’s I crushed (severely dented) the balky condenser and the spark settled right down and I was able to drive home and re install the old one .
These days I prefer breakerless ignition up grades, Pertronix ‘Ignitor’ systems and the 1/2 price Chinesium copies (no, they don’t fail unless you use the WRONG COIL) but remembering the things one learned 50 + years ago is fun .
-Nate
OBTW : a handy tip ~ if your old points are wearing evenly, IE no tit and crater, DO NOT REPLACE THE CONDENSER ! .
It’s *perfectly* matched and will give extremely long points life .