Hot-Wiring Nightmare No-Starts

by | Nov 2000 | General, Import Service | 0 comments

No-starts? Piece of cake. Except when they’re not.

Here are some that weren’t, and how they were fixed by a very special hot-wire: the iATN.

To a ‘civilian,’ a no-start seems like the most frustrating and difficult of all car problems. It’s always unexpected and inconvenient. And entirely inexplicable! After all, ‘didn’t the engine start fine thousands of times before, with the same gas in the tank and the same key in the ignition slot, just like now? Doesn’t it look and sound the same? What could this problem be?

What’s it gonna cost?’

But for professional mechanics, no-starts are, if not brain-off routine, at least regular problems almost always yielding to ordinary diagnostic steps. You check for cranking voltage and speed, for spark and for gas (injector pulses for the most part, a squirt down the venturi on older carbureted vehicles). No spark? No fuel? This is the time to extract whatever codes may be in the computer —remembering that they not only refer to circuits, not components; but remembering as well there are many unintended software ‘pranks’ that can mislead you.

Examples? Most Eurocar shops already know how a jumped tooth on a VW timing sprocket can often set a code indicating a lost distributor ground. Why? Because crank and cam position signals fall out of synch, and that’s the first reason for such an unmeshed electrical signal the engineers thought of when listing the codes. Want another? One of our readers pointed out in Tech Tips recently that S-class Benz cars can fall into limp-home — nearly no-start — if both brake light bulbs have burned out filaments. Why? It never occurred to the Stuttgart engineers that someone would let a burned bulb go long enough for the other to go, too, and a brake bulb check is part of the cruise control system bootup.

No brake lamp filament, no electric throttle. And it’s a drive-by-wire car. You’ll find an entirely use-less cruise-control DTC.

The point: Use the codes as guides, but test things directly. If you think you have no spark, pull out your spark tester, not an old spark plug, and watch for a blue snap half an inch long.

Just no gas, by itself? Check the pressure and volume. Most people skip the volume test because it’s inconvenient. I always did myself, until the first car with good pressure but insufficient volume gobbled up many hours before I realized the machine was conking me over my thick noggin for stubbornly working hard but not smart. The volume test also lets you see just what you have a volume of, by letting the stuff sit and stratify over fifteen or twenty minutes. Enough water, Diesel fuel, crankcase drain oil, flaked-off tank rust or plain old dirt account for many a no-start. To ensure fuel volume, Sam Bell, Import Service ace contributor, says he now pours a gallon of gas into almost every no-start towed into his shop, ever since he was fooled once by a dead car with an empty tank but a gauge stuck at half-full.

If the engine cranks too slowly, you look for volt-age drops in the starter circuit or mechanical bind-ing in the starter nose bushing, but remember that a worn engine can crank at normal speed even with a weak battery. Those limp rings and slack bearings don’t make drag or compression. If it cranks too fast, sounding like an electric drill spinning in the air, you’ve probably got a broken timing belt and on most current engines a few bent valves. Nothing so far? Spin the plugs out, grab your oil can and battery charger and launch a dry-then-wet compression test for each cylinder.

But when you get beyond the compression test and still don’t know why it’s not running, you start to get That Feeling – one of Those Cars has returned. Some people, more than twice burned and thus more than twice shy, just pass on the car at this point. More adventurous people toggle into puzzle-solving mode and set out to sort it out, for fun or profit — sometimes more of the first than the second.

I’m not going into procedures that reveal the workings of theft-prevention systems here because I don’t want to provide a ‘Cliff’s Guide’ for car thieves and repo crews. For those problems, see what you can find out from the carmaker (many of whom will tell you nothing). These no-starts are all from the iATN, the International Automobile Technicians Network, real-world ‘Help!’ posts sent to that network’s 30,000+ membership and solved (usually but not always) with the help of advice sent back over that same hot-wire, the telephone line.

Download the PDF to read more…

Search All ATI Content:

Search by Publish Date

Related Articles

2006 Hyundai Santa Fe Heater Blower With No Speed Control

2006 Hyundai Santa Fe Heater Blower With No Speed Control

This specific HVAC system has no self-diagnostic abilities, but does control the blend doors and A/C while manually controlling the blower motor speed. This article is intended for the learning technicians that have an interest in diagnosing and testing a Hyundai HVAC...

read more
How to Scan a 2018 Alfa Romeo Stelvio

How to Scan a 2018 Alfa Romeo Stelvio

This story begins at the local coffee shop. We noticed at the drive-through a modern Alfa Romeo. A chat with a close friend revealed that the vehicle owner was displeased with the local dealer and a contact was created. Displeased with the dealer was a mild term. The...

read more


Submit a Comment