View single post by NJ_Brit
 Posted: 08-25-2016 12:54 pm
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Joined: 06-16-2016
Location: Martinsville, New Jersey USA
Posts: 16
Looking for some advice here.  I've had my JH for a few months and am experiencing an intermittent problem that I'd like to identify some possible culprits for.  I know enough about engines to be dangerous...

The stock engine is running Dellorto's that were rebuilt by the previous owner, who added the rubber expansion gaskets to address vapor lock.  He also replaced the coil and distrbutor.  The car gets driven at least once a week and has fresh fuel.  The engine has good oil pressure, doesn't overheat and the electrical system seems ok (if you believe the gauges on the dashboard).

The engine starts up just fine, and idles smoothly more or less straight away.

However, at random, when accelerating up to or cruising at 30 - 40 mph the engine just flatlines.  The Rev Counter drops to zero RPM and there is no response at the throttle at all.  The engine is still running, but barely.

This happens at random, but usually a short while after starting the engine or restarting it.

On a couple of occasions I've had to shut down the engine completely, and then restart - which requires some cranking.  The last time it happened, the engine came back to life after I floored the throttle a few times, without needing a restart.

Once restarted the engine runs just fine with no issues.

My initial thought was that this was a fuel supply issue (bad pump, crap in the fuel supply), but I think the carbs are running a bit rich (I get a lot of pops and crackles through the exhaust on overrun) so it could be they need looking at.  However from reading through a few posts on here it could be electrical related.

Has anyone seen this, or do you have any advice where to start looking?

Last edited on 08-25-2016 01:12 pm by NJ_Brit