92 Griff 400 cranks fuel spark present but won't start

[jauntyviper]

Hi all,

I’m hoping for some guidance on a starting issue with my 1992 Griffith 400.

Yesterday it started normally in the garage, but I stalled it while pulling out. Since then, it hasn’t restarted — 24 hours and many attempts later it still just cranks, occasionally sputtering but never firing properly.

Here’s what I’ve done so far:

Battery and cranking voltage:
Initially suspected a low battery, so I connected it to a running vehicle for jump assistance. Cranking speed sounds normal. Voltage at the battery while cranking stays around 12 V, and at the coil it drops to about 9 V. I’ve run a direct feed from the battery to the coil +ve, which kept the voltage up at about 10 V, but it still wouldn’t start.

Fuel:
Fuel is fresh. Plugs are wet after cranking, so injectors are working.

Spark:
Confirmed spark at the coil and at the plugs via the distributor.
I suspect the spark might be weak, but that’s subjective.

Compression and air:
Compression test is normal. No air intake obstruction found.

Ignition system:
Distributor definitely turns when cranking.
I removed and cleaned the distributor cap, arm, and points. HT leads all reseated, all plugs checked secure.
Primary resistance across the coil is about 0.9 Ω.
Cleaned all coil connections.
I’ve not yet confirmed exact ignition timing, as I couldn’t reliably find TDC on cylinder 1, but the distributor appears correctly seated.

ECU diagnostics:
Connected RoverGauge, no fault codes reported. RPM reading during cranking is steady and sensible, so the pickup signal is reaching the ECU.

At this point, I’ve confirmed:

• Air, fuel, and compression are all present.
• Spark exists, but may be weak or mistimed.
• Coil voltage under load is marginal but within range after bypassing the ignition feed.
• ECU is seeing engine speed and fuelling accordingly.

Given all that, I’m currently leaning towards either a failing ignition amplifier or an ignition timing issue, but before I start swapping parts I’d really appreciate any input from others who’ve chased a similar fault on a Griffith or Rover V8.

Thanks in advance for any thoughts or tests I might have missed.

[Phud]

sound much like the amp failure, I had the same and it was really annoying.

[blaze_away]

Sounds like it's been flooded to me.

Whip all the plugs out and crank it over to blow out any remaining fuel. Whilst they are out wire brush the plugs clean and make sure they are gapped correctly.
Put the plugs back in and then try starting it again.

[Belle427]

I would agree with the above, if you have a blow torch run it over each plug tip for a few seconds when you have them out.

[jauntyviper]

You are absolutely right guys, thank you very much for your wisdom!

This morning I pulled all the plugs out, it was interesting to note that they were already dry from yesterday s attempts, so not currently flooded, but I took them to the workshop and blowtorched them, wire wheeled them, and when I checked the spark plug gaps many of them were far too small, one of them I think even in contact with the electrode. I regapped them all at 0.7 mm per the plug spec.



Before re-fitting them, I pulled out the fuel pump fuse and cranked the engine to make sure it pushed out any remaining fuel in the cylinders, refitted all the plugs, replace the fuse.

I turned the key and it fired right up. Took it for a drive to get some heat into the cylinders, there s still a small misfire when suddenly accelerating hard, but that was there before, I think that s a project for another day.

Thanks everybody, you ve saved me a lot of parts buying.

[Belle427]

Try not to just start the car and leave it ticking over a lot or it will foul the plugs, they look to be NGK BPR7ES, BPR6ES may be a better choice to help stop fouling so easily.