11-05-17, 02:13 PM
Leads or plugs can cause this. Check drain hole is clean and no water moisture around plugs.
WB40 leads etc
New plugs ?
Air leak, if you get a can of easy start and spray around pipes engine revs will pick up if air leak.
Be careful and check leads and plugs first for shorting, don't spray too much, its flammable.
Old trick we used on cars