Discovery 1 with RPM play when going uphills

Jay Frem

Member
Nov 29, 2005
10
0
Hi There

I am running a 1996 Discovery 1 3.9 L V8 ( has the 4.l Engine Block) with Auto gearbox. When accelerating uphills with heavy throttle i tend to get a RPM play at 2800-2700 then it would back to 3000 RPM.

I recently put a used Lucas MAF bought off ebay which seems to be OK. Still get occasional high idle ( 1300-1400) when shirting to N or P after a drive and then it settles to 750 RPM after few seconds.
Previously i was running a MAF i bought off Paddock spares which was doing OK but was slowed to bring rought idle down when shifting from D to N or D to P.

Could the RPM play going uphills be caused by : spark plugs, MAF, Fuel Pump ? Torque converter ? Do spark plugs go bad if truck is not driven often ?

Air Filter and Fuel filter have been changed. Took out 1 spark plug and it seemed to be OK.

Thanks for the insights
Jay