1 Help - Mis-firing 16V Tue Apr 05, 2022 7:48 pm
stanthomas
Silver member
One for the group...looking for suggestions for where to start. Lot's of info on the site but nothing quite matches my situation so I hope someone can offer some tips on the most likely cause(es).
Just fixed the oil/water pump. Was running fine and doing about 50 miles a day. Some dual-carriageway (highway) and some back roads.
On my way out, engine warmed up and about 5 miles in, briefly hit "good morning judge" speeds on dual carriageway. Just another day. Total of 15 miles up on journey, had slowed to 70-ish mph and rolling along in traffic when it started mis-firing. Fuel gauge was flicking into the red but low fuel light wasn't on. Stopped for fuel (E5 super as ever) but that wasn't it. Very, very lumpy pull away like it's lost half a cylinder but will roll at 70-ish on light thottle - bit rough and no get-up-and-go but sort of drive-able and I was able to get to my destination and home again. Won't really tick-over without some throttle and is very. very rough. All four exhaust pipes are hot. No water in oil or oil in water. Squirted WD40 around the throttle bodies and intakes and no obvious signs of leaks.
In last 2000 miles it has had:
- new plugs and leads (pulled plugs and sparking on all 4. All plugs look fine and same.)
- new fuel filter and in-tank pipes (pulled pipe to injector rail and fuel pumps out - although it stops after a few seconds. And fuel returning to tank when connected.)
So guys, what goes bang, all of a sudden while rolling along, one moment fine, next moment terrible? And stays terrible but doesn't get any worse (although that would be difficult).
Just fixed the oil/water pump. Was running fine and doing about 50 miles a day. Some dual-carriageway (highway) and some back roads.
On my way out, engine warmed up and about 5 miles in, briefly hit "good morning judge" speeds on dual carriageway. Just another day. Total of 15 miles up on journey, had slowed to 70-ish mph and rolling along in traffic when it started mis-firing. Fuel gauge was flicking into the red but low fuel light wasn't on. Stopped for fuel (E5 super as ever) but that wasn't it. Very, very lumpy pull away like it's lost half a cylinder but will roll at 70-ish on light thottle - bit rough and no get-up-and-go but sort of drive-able and I was able to get to my destination and home again. Won't really tick-over without some throttle and is very. very rough. All four exhaust pipes are hot. No water in oil or oil in water. Squirted WD40 around the throttle bodies and intakes and no obvious signs of leaks.
In last 2000 miles it has had:
- new plugs and leads (pulled plugs and sparking on all 4. All plugs look fine and same.)
- new fuel filter and in-tank pipes (pulled pipe to injector rail and fuel pumps out - although it stops after a few seconds. And fuel returning to tank when connected.)
So guys, what goes bang, all of a sudden while rolling along, one moment fine, next moment terrible? And stays terrible but doesn't get any worse (although that would be difficult).
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K100RS 16V '91