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V6 Lumpy idle or normal for model?
Posted: Wed Mar 20, 2019 12:13 pm
by lucklesspedestrian
Hi
Just wondering if any other V6 owners have noticed a vibration at idle coming from (obviously!) under the seat. I was just wondering if other folks V6's were silky smooth at idle or is it a case of 'they all do that sir!"
The engine certainly smooths out nicely on the move and the 'lumpiness' is less pronounced with a warm engine. I suppose my problem is that I'm used to modern petrol car engines, conventionally located in the front and have no idea what a older V6 under the seat is meant to feel like.
Any thoughts?
Re: V6 Lumpy idle or normal for model?
Posted: Wed Mar 20, 2019 12:36 pm
by g8dhe
Check over the ignition system, leads deteriorating and oil in spark plug wells are a common cause, also distributor rotor and points can cause problems.
Re: V6 Lumpy idle or normal for model?
Posted: Wed Mar 20, 2019 3:11 pm
by lucklesspedestrian
g8dhe wrote: Wed Mar 20, 2019 12:36 pm
Check over the ignition system, leads deteriorating and oil in spark plug wells are a common cause, also distributor rotor and points can cause problems.
Thanks Geoff, I'll get that checked out. Blimey! the Bongo still has points and a distributor eh....I did not know that!
Re: V6 Lumpy idle or normal for model?
Posted: Wed Mar 20, 2019 3:49 pm
by g8dhe
Distributor contact points I should have referred to not contact breaker points that is electronic
Re: V6 Lumpy idle or normal for model?
Posted: Wed Mar 20, 2019 3:54 pm
by lucklesspedestrian
Understood
You'll be telling me I need the carbs balanced next!
Re: V6 Lumpy idle or normal for model?
Posted: Wed Mar 20, 2019 4:06 pm
by g8dhe
Only if you're in to "healthy" eating it seems
Re: V6 Lumpy idle or normal for model?
Posted: Wed Mar 20, 2019 7:58 pm
by Doone
Re: V6 Lumpy idle or normal for model?
Posted: Wed Mar 20, 2019 8:43 pm
by haydn callow
What are
the revs at idle ?
Re: V6 Lumpy idle or normal for model?
Posted: Wed Mar 20, 2019 9:31 pm
by lucklesspedestrian
haydn callow wrote: Wed Mar 20, 2019 8:43 pm
What are
the revs at idle ?
I'll have a look in the morning and post back!
Re: V6 Lumpy idle or normal for model?
Posted: Thu Mar 21, 2019 11:00 am
by lucklesspedestrian
lucklesspedestrian wrote: Wed Mar 20, 2019 9:31 pm
haydn callow wrote: Wed Mar 20, 2019 8:43 pm
What are
the revs at idle ?
I'll have a look in the morning and post back!
Seems to be sitting at a fraction over 1000rpm at idle with the engine not quite fully warm.
Re: V6 Lumpy idle or normal for model?
Posted: Thu Mar 21, 2019 11:04 am
by haydn callow
That’s high, but I was hoping you would say 600 which is low and could be the cause of the lumpy running....from memory mine used to run at 800 and smoooooooth.
Re: V6 Lumpy idle or normal for model?
Posted: Thu Mar 21, 2019 11:09 am
by haydn callow
So next clean the rotor arm and contacts in the distributor.... and remove the ignition leads one at a time from the plugs and examine very catefully for dirt oil or cracks,,,,check oil has not collected round the plugs....clean everything and try and see if problem still there. Go out when it’s really dark and look for tracking of spark.
Re: V6 Lumpy idle or normal for model?
Posted: Thu Mar 21, 2019 11:59 am
by lucklesspedestrian
haydn callow wrote: Thu Mar 21, 2019 11:09 am
So next clean the rotor arm and contacts in the distributor.... and remove the ignition leads one at a time from the plugs and examine very catefully for dirt oil or cracks,,,,check oil has not collected round the plugs....clean everything and try and see if problem still there. Go out when it’s really dark and look for tracking of spark.
That's really weird. The only other Mazda I had was a Xedos 6 with a 2.0 litre V6 engine (very pretty car). It had that very issue with the tracking spark which if I remember correctly, as you say could be seen in the dark but also was there something about spraying water from on of those plant water bottles to show up the tracking? Anyway it cost a bloody fortune for a new set of HT leads for the thing and I got rid soon after. Must have been one of the smallest V6's out there?
Re: V6 Lumpy idle or normal for model?
Posted: Fri Mar 22, 2019 3:44 pm
by Bonneville
I had a Mitsubishi FTO Mivec 2.0 V6. Japanese tax bands are 1.5l - <2.0 then 2.0 - <2.5 and so on. Means you get some weird marketing attempts for the given engine size. Also means our Bongos got the 2.5 V6 rather than the 3.0 in the 929 for global markets.
A 2.0 V6 is an abomination really as there is little benefit over a 4 for that capacity. That FTO made 200BHP but felt like a motorbike engine as it was all revs and no torque down low. It gets weirder if you're into motorbikes, there's a subculture of JDM 4 cylinder bikes at less than 250cc. 20K RPM redlines!
Re: V6 Lumpy idle or normal for model?
Posted: Fri Mar 22, 2019 11:41 pm
by Russell Jupp
Bonneville wrote: Fri Mar 22, 2019 3:44 pm
I had a Mitsubishi FTO Mivec 2.0 V6. Japanese tax bands are 1.5l - <2.0 then 2.0 - <2.5 and so on. Means you get some weird marketing attempts for the given engine size. Also means our Bongos got the 2.5 V6 rather than the 3.0 in the 929 for global markets.
A 2.0 V6 is an abomination really as there is little benefit over a 4 for that capacity. That FTO made 200BHP but felt like a motorbike engine as it was all revs and no torque down low. It gets weirder if you're into motorbikes, there's a subculture of JDM 4 cylinder bikes at less than 250cc. 20K RPM redlines!
Ha! I love my bikes, and I love engines. I have a small collection of low capacity Jdm fours that can reach incredible rpm, including a little v4 with gear driven cams. The engineering in all these machines is simply superb. Quite incredible.
