Thread: Weird drivablility issue, 1993 RRC 4.2 Petrol

Hello!

I recently purchased a 1993 Classic LWB from an acquaintance, and through the month I've owned it, I have had to fit a new fuel pump, and replace the top radiator hose where the fan temp sensor fitting sprung a leak.

It's fitted with a 4.2L V8, and a 4-speed auto-tragic gearbox.

Since I've owned it, it's had a weird drivability issue. Some days, it will not run worth a damn below 3,000 rpm. If I take it on the highway, 110kph, it will buck and spit, and have absolutely no power in overdrive. If I manually select 3rd gear, it will pull all day long without missing a beat. At lower speeds, it will still buck and spit, but not nearly as bad when as on the highway.

Other days and nights, it will run like a dream in overdrive.

I thought maybe the vacuum advance in the distributor was giving me fits, so I disconnected the vacuum hose which did nothing other than make it feel more like a dog than usual (bucking and sputtering continued). I did get a code for the bank A lambda sensor, so I disconnected the battery, disconnected both lambda sensors (to force the fueling to remain open loop) and it kept on with the bucking and spitting.

When it does begin to run poorly, I begin to smell what I think is very angry catalytic converters.

Right now, I'm wondering if it's not the ignition coil. It appears to be original, but I'm not entirely sure why it would cause issues some times, and not others. I'm also fishing for other ideas.

Thankfully, this is my bug-out truck/fun toy, otherwise I'd have already lit it on fire and rolled it down a hill.

Originally Posted by bee utey

I've experienced similar symptoms from the original Lucas ignition module on its last legs. In Australia I use a locally sourced Bosch ignition module and convert it. However in the US you can use the early type of Chev HEI 4 pin module. Indeed this is the module used in the first versions of the Land Rover electronic ignition using a magnetic pickup. The Range Rovers used them around 1985.

Thread here:

Lucas ignition amplifier replacement by Bosch 024

The most recent post shows the HEI module in its nest.

Thanks for the advice...I have mended it for now until I can get the time and money to get it swapped. I ran 18ga wire through a fusible link straight to the coil from the battery, as the factory wiring looked kind of botched together. Seems to have done the trick, it'll drive all day long with no problems.