Yet more idle problems

[green light]

Not sure if anyone has experienced this problem before. I have an 89 rr 3.5 with a Lucas L injection system. One issue seems to be the vehicle has taken a liking to stalling at idle in all gears bar neutral & park. Vehicle idles at about 750-800 depending on its mood but as soon as a gear is selected drops to about 250 rpm. That combined with a slight miss at idle every few seconds seems to cause the thing to die. I have discounted a fuel problem as I have it just converted to gas & the problem was there before & is still there now. I replaced the plugs, leads, rotor button & dizzy cap to overcome the miss but to no avail. If anyone has any ideas on what helps the engine maintain idle speed when under load or what else I could try to overcome the miss I would be very gratefull.

[RaginRover]

Adjust your idle bypass valve so it idles ok or reset you base idle

Tom

[the_grubb]

I had a similar problem once, may or may not be the same cause.

Would idle in Park & Neutral, but sparks were jumping across the terminals of the coil, when put in a gear the extra load would kill it unless you could get the revs up quickly enough.

[green light]

Thanks fellas for your advice but the old lucas injection system doesnt have a base idle adjustment to compensate for extra loads such as a/c etc. After further investigation found there were two different faults. One being a cracked vacuum hose causing a loss in vacuum under load so unable to maintain idle & the other being a closed gap on one of the new plugs on number one cylinder causing the miss.