He couldn't speak it, let alone write it. [bigwhistle]
A definite lack of diversity in school subjects, back then. [biggrin]
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He couldn't speak it, let alone write it. [bigwhistle]
A definite lack of diversity in school subjects, back then. [biggrin]
This one I did in Copilot using the Think Deeper setting. I'm doing diagnostics on a non-sparking 3.5V8Quote:
Originally Posted by loanrangie
Trying to trouble shoot an ignition system on a LAnd Rover Discovery 3.5 V8. There is no spark from a spark plug attached directly to the ignition coil. The coil is getting power and it is getting power while cranking the engine. I have fitted a new ignition module and checked this is getting returned power to the coil. I have tried new leads and new spark plugs. What else can I check to get spark?
Got it, Simon—no spark right at the coil tower narrows things down nicely. On the Rover 3.5 V8 (Disco 1–era), the coil only throws a spark if it’s getting a solid supply and its negative terminal is being switched by the ignition amplifier/distributor pickup. Here’s a practical, step‑by‑step flow you can run through in the driveway.
1) Basics: power & grounds while cranking
- Battery voltage under crank: Make sure the battery stays healthy (>~10 V while cranking). Low voltage can kill ignition energy.
- Grounds: Do a quick voltage‑drop test while cranking—measure between battery negative and the coil bracket/distributor body; aim for <0.2 V. Clean the engine‑to‑chassis earth strap.
(General good practice; no external source required.)
2) Verify coil type & resistance (quick meter checks)
The 3.5 V8 commonly uses a Lucas electronic‑ignition coil (e.g., DLB198 / RTC5628). Check yours with a multimeter:
- Primary resistance (between + and −): Expect roughly 0.7–1.0 Ω on DLB198‑type coils. [holden.co.uk], [britishautousa.com], [partsinmotion.co.uk]
- Secondary resistance (centre HT to −): Typically ~7–9 kΩ on DLB198‑type coils. [holden.co.uk], [britishautousa.com]
If your readings are way outside those ranges, the coil may be faulty even if it has power.Also confirm your coil model suits electronic ignition (DLB198 family) used on these engines. [island-4x4.co.uk]
3) Check for a ballast/resistance feed & crank bypass
Many Rover V8 installations use a ballast resistor or resistance wire feeding the coil with a bypass during cranking from the starter solenoid. If the ballast feed is open (or bypass missing), you can have 12 V present but still get a weak/no spark in certain key positions. Inspect for a ballast resistor/resistance wire in the loom and confirm the bypass feed is live during CRANK. [johnrichar…plus.co.uk], [lrparts.net]
4) Is the coil negative actually being switched?
You can test this with a test light:
- Clip a test light between coil − and battery +.
- Crank the engine. The light should flash if the ignition amplifier/distributor pickup is toggling the coil. If it doesn’t flash, the fault is upstream (pickup, amplifier, wiring). [tomorrowst…nician.com]
A classic bench check of the coil itself:
- Fit a plug to the coil HT tower and earth the plug body.
- Apply 12 V to coil +. Make & break the connection to coil − to simulate switching—each break should produce a spark. If no spark, suspect the coil. [landyzone.co.uk]
Tip from that thread: don’t hard‑earth the coil negative—if it’s tied to ground permanently, you’ll never get spark. [landyzone.co.uk]
5) Distributor pickup & air gap (very common culprit)
On the Lucas electronic distributors (e.g., 35DLM8), the magnetic pickup inside must be healthy and gapped correctly:
- Pickup resistance test: Unplug the two pickup wires and measure across them—you should see “thousands of ohms” (kΩ range) and the reading will fluctuate as the reluctor passes the pickup. [landyzone.co.uk]
- Air gap: Set the reluctor/pickup air gap to 0.20–0.35 mm (0.008–0.014"). Use a non‑metallic feeler if possible. [lr4x4.com]
If the rotor doesn’t turn while cranking, the drive gear/oil pump drive engagement is suspect—but if you’ve got good mechanical rotation, focus on that pickup gap and signal.
6) Ignition amplifier/module & its mounting
Early setups mounted the ignition amplifier on the distributor body; heat soak and dry joints made these notorious for intermittent/no‑start failures. Many folks relocate the module to a cooler spot near the coil. Even with a new module, confirm solid ground and good connectors; relocating can improve reliability. [v8forum.co.uk]
For additional context and testing hints on these Rover V8 amplifiers and distributors, this “Ignition Masterclass” video shows bench‑testing the amplifier and generating spark with a simple rig. [youtube.com]
7) Cap/rotor & HT path sanity checks
- Inspect the distributor cap’s centre carbon brush and spring—if missing/broken, the coil’s HV never reaches the rotor.
- Try a known‑good HT lead from coil tower to a plug with a 8–10 mm gap spark tester.
(General good practice; no external source required.)
8) Wiring logic (keep it simple)
- Coil + should get a clean switched 12 V (RUN) plus a bypass feed (CRANK) in ballasted systems. [johnrichar…plus.co.uk], [lrparts.net]
- Coil − is controlled by the ignition amplifier (and typically also feeds the tachometer). Make sure it’s only connected through the amplifier—not bolted straight to ground. [landyzone.co.uk]
9) If you had the distributor out (timing sanity check)
- Set No. 1 cylinder to TDC on compression and align the rotor to the No. 1 post.
- Fit leads clockwise in 1‑8‑4‑3‑6‑5‑7‑2. [v8forum.co.uk]
Quick decision tree
- Test light on coil − flashes while cranking?
→ Yes: Coil or HT path (cap/rotor/lead) likely at fault. Re‑try the bench “make & break” coil test and inspect cap/rotor.
→ No: Focus on pickup air gap/resistance and amplifier wiring/ground. Consider relocating/replacing the module if mounted on the distributor. [landyzone.co.uk] [landyzone.co.uk], [lr4x4.com], [v8forum.co.uk]- Ballast/bypass present and working during CRANK?
→ A missing/open ballast feed or dead bypass can produce a no‑spark symptom; verify both. [johnrichar…plus.co.uk], [lrparts.net]- Coil resistance out of spec?
→ Replace the coil with the correct Lucas electronic‑ignition spec (DLB198/RTC5628 family). [island-4x4.co.uk], [holden.co.uk], [britishautousa.com]
What I’d like to know to tailor this further
- Is yours carb or EFI? (Both use the distributor pickup + amplifier, but wiring/ballast details can differ.)
- Where is the ignition module mounted—on the distributor or remotely near the coil? [v8forum.co.uk]
- What coil part number is fitted (e.g., RTC5628, DLB198, PRC6574, etc.)? [lrdirect.com], [advancedfa…tors.co.uk]
Share those, and I’ll map your exact wires/voltages and the next tests to run. If you want, I can also pull the relevant pages from the V8 overhaul/service docs to cross‑check specs. [ovlr.ca], [tmbbooks.com]
If you’re stuck at any step, grab your meter and I’ll walk you through the reading you should see (RUN vs CRANK) and what it means.
Oddly I know who and most of us know some yet few know Cicero how was one of the last great senators of the Roman Republic, whose writings have shaped our perception of the Roman world and the Latin language.Quote:
Originally Posted by Tins
Also a rip snorter of a book to read[thumbsupbig][thumbsupbig][thumbsupbig] "The Cicero Trilogy"
Keep safe and hydrated all.
Why the hell did you have to bring him up? I'm having Jacob's Ladder style flashbacks already. I didn't have to read him, I had to translate him. No wonder I grew up grumpy.Quote:
Originally Posted by NavyDiver
Or perhaps Python ones.Quote:
Originally Posted by Tins
https://youtu.be/0lczHvB3Y9s?si=aa2uqfgiNa1YR7ZL
Speaking of AI and fights someone used AI to make an article with pictures about Alsn Kohler fighting the Comm Bank CEO...AI is evolving fast and may bring the fourth industrial revolution with it - ABC News
Alan raises some interesting points like the''socials" are finished if seeing is no longer believing, but I'm not so sure, maybe a lot of people like mindless drivel in picture format.
This guy says some interesting stuff about it, from a young bloke's perdpecrive. Unfortunately he also says it using a couple of expletives, so I will break it ( most of us would probably use them more than he does )
https://youtu.be. /gCGyyHh29A4?si=ANeSEQ8DHSqEou66
This guy says some interesting stuff about it, from a young bloke's perdpecrive. Unfortunately he also says it using a couple of expletives, so I will break it ( most of us would probably use them more than he does )
htt ps://. youtu.be. /gCGyyHh29A4?si=ANeSEQ8DHSqEou66