Yeah, the material specific to fuel injection and ignition is (obviously) not useful. But the electronics and circuit testing material is just as effective! You'll be able to walk through electrical problems the same way as on a gas engine.
Injector waveforms are very different on common rail but how you capture them is exactly the same. With common rail it is important to have a known good injector waveform as they vary a lot between engine types. Pressure sensors, crank & cam sensors are exactly the same as on petrol/gasoline or LPG engines 0-5v. Same goes for low pressure electric fuel pumps and temperature sensor
Cranking compression test using an amp clamp is even more useful for diesels, the amp clamp is also great for checking Glow plug operation.
One test to learn with common rail that is not used in gasoline engines is the injector leak back test --- low tech but a vital to spot a bad injector causing a long crank time.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Thanks for the post. I don't think my Autoenginuity PC-based scanner will display injector wave forms--does that require an oscilloscope. And, my Duramax has all the usual 5v and 12v sensors.
I presume the cranking compression test with amp clamp is covered in the book? Where can I read up on checking glow plugs with an amp clamp?
I'm familiar with injector return rate test for my truck, is that the same as a leak-back test?
I've replaced 3 injectors in my truck based on balance rates which I can watch with my scanner. At 200K miles, mostly towing my trailer, I get quick starts and a smooth Idle.
The thing about the book and videos is they teach basic methods that work from first principles. All piston engines (in fact all combustion engine including jets) require the same basic things air, compression, a metered amount of fuel, some way to time the ignition and a way of getting rid of the exhaust and waste heat.
On modern engines all these are controlled by electronics, the electronic control of all these is by pretty much pulled from the same box of trick and applies to equally 30,000 shp marine 2 stroke diesels that are so big you stand inside the cylinders as tiny Asian 3 cylinder economy .
The cranking compression test is really quite simple, when you operate the starter to crank the engine every time a cylinder is on the compression stroke huge extra spike of current is taken from the battery. The most common way to do a cranking compression is to use a current clamp that connects to an oscilloscope and with the fueling disabled crank the engine for several seconds, on a good engine all the current spikes due to will be of equal height, so it is easy to spot a cylinder with poor compression.
The amp clamp applies to checking a set of glow plugs, for example if each glow plug draws 8 to 15 amps on V8 engine the current through the glow plug fuse should be a whacking 64 to 120 amps and this could be very easily measured with an amp clamp so any bad glow plugs causing a non-start or misfire on start-up will show up as lower than expected current.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
bud46 wrote: Anybody finding the book useful for modern common rail diesel? I have an '05 Duramax. Save the fuel injection I would think it would be very useful.
Any comments, thoughts, or reviews would be appreciated. Thanks
I very seldom work on cars, except my own or friends occasionally. I work on diesel powered equipment which is now loaded with canbus and common rail. I have subscribed and am studying all of Paul’s material and although it isn’t specific to what I do, i am using this knowledge all the time in troubleshooting/repairing hydraulic systems and Diesel engine control.
