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Rev Worries V6

Posted: Mon Oct 15, 2012 9:09 pm
by Bogmonster40
No I am not confessing to any shenanigans about my time as a choirboy [-X :lol:
I left my home today to drive into Cardiff, after about 3 miles I pulled up to a set of traffic lights when my rev counter started going from 2500 to 0 then stalling. After re-starting it was as if someone was revving the engine as it was now going from 1000 revs to 0 and stalled again. I pulled over as I was worried something was about to go on it. After turning the engine off and trying to ring a couple of people who are more knowledgeable than me, sadly no-one was awake...... #-o
After about 5 mins I re-started the car and it was fine. Coming home 7 hours later it was still fine.

Obviously there is an issue with my engine but I cant find any answers on here or google - any suggestions anyone :roll: :roll: :roll:

Re: Rev Worries

Posted: Mon Oct 15, 2012 9:19 pm
by M 80NGO
Petrolium or Deisolium ? If petrol it could be the idle control unit tho tbh i'm not genned up on the petrol variant do they even have an idle control valve ? could also be Mass air flow meter. Could even be a perforated inlet hose from the air box to the inlet manifold.

Re: Rev Worries

Posted: Mon Oct 15, 2012 9:22 pm
by jaylee
:-k Hi, Just read of your plight... I see you have a V6 with LPG...? Any cruise control fitted...? I'll keep my head down now & let the experts put in.... 8)

Re: Rev Worries

Posted: Mon Oct 15, 2012 9:24 pm
by jaylee
M 80NGO wrote:Petrolium or Deisolium ? If petrol it could be the idle control unit tho tbh i'm not genned up on the petrol variant do they even have an idle control valve ? could also be Mass air flow meter. Could even be a perforated inlet hose from the air box to the inlet manifold.
:lol: Fat lot of help we are!!!?? :wink:

Re: Rev Worries

Posted: Mon Oct 15, 2012 9:32 pm
by M 80NGO
But atleast we're trying, Very trying !!!!!!!! :lol:

Re: Rev Worries V6

Posted: Tue Oct 16, 2012 6:09 pm
by rita
Hi,

It sounds like injector timing malfunction.

Re: Rev Worries V6

Posted: Tue Oct 16, 2012 8:34 pm
by haydn callow
My V6 does exactly as you describe after 2/3 miles......in my case the reason is, that is about how long I have to drive to get the temp up to 40C where it switches from petrol to LPG. If I happen to stop for any reason at this point ( or until my temp gauge reaches 48C) the engine will stall.......once you know this is the problem it is easy if you have to stop to "flick" it onto petrol......I have a aftermarket digital temp gauge fitted so I can predict the problem before it happens......once you know what,s happening it is no longer a problem...

Re: Rev Worries V6

Posted: Tue Oct 16, 2012 9:04 pm
by M 80NGO
haydn callow wrote:My V6 does exactly as you describe after 2/3 miles......in my case the reason is, that is about how long I have to drive to get the temp up to 40C where it switches from petrol to LPG. If I happen to stop for any reason at this point ( or until my temp gauge reaches 48C) the engine will stall.......once you know this is the problem it is easy if you have to stop to "flick" it onto petrol......I have a aftermarket digital temp gauge fitted so I can predict the problem before it happens......once you know what,s happening it is no longer a problem...

That was gonna be my next guess :D

Re: Rev Worries V6

Posted: Tue Oct 16, 2012 9:07 pm
by New Forest Terrier
Agree with Hayden its the LPG switch over. Mine started doing this for the winter this week as its got colder. Usually it switches over totally painlessly, but if the switchover happens when stopped at a junction, it can stall. A chilly day makes this more likely, in warm weather you can stop and start no problem. Cure is just watch the temperature gauge, I have one of Haydens TM2's or just time it. If you have to stop within the first few minutes, switch to petrol until all is warm or you have a straight bit of road for it to do the changeover. Often just it revving in neutral until the LPG light comes on will keep it running.

A lpg service could improve things. Mine was much worse last winter when recently converted, improved with a service and was totally cured all summer.

Re: Rev Worries V6

Posted: Tue Oct 16, 2012 9:17 pm
by mikeWalsall
Similar to my V6 /LPG .. when cold it starts / runs / ticks over 100% perfect on petrol, but at low speeds when it first switches over to LPG the rev counter fluctuates quite a bit, plus it's prone to stall / run lumpy at tick over until the engine has really warmed up ..

The the guy who fitted my LPG last December as gone kapput, as he did not put my Bongo on the LPG / insurance register I had to get it checked and certified by the Walsall Autogas guy who converted my Toyota Emina .. I mentioned this issue to him and he said when I take it for it's LPG service he should be able to tune the problem out with his lap top ..

Re: Rev Worries V6

Posted: Tue Oct 16, 2012 9:23 pm
by Bainsy
Certainly not a normal problem. My bongo is V6 LPG and I have owned it since March this year, have done about 6k miles and experienced no problems at all when it changes from petrol to LPG after a few miles. Maybe a LPG service required?

Re: Rev Worries V6

Posted: Tue Oct 16, 2012 9:32 pm
by mikeWalsall
Mine is OK when leaving home and going for a run .. it's more of a low speed problem while in stop start traffic when it first switches over to gas ..

Re: Rev Worries V6

Posted: Wed Oct 17, 2012 12:16 pm
by AeroNut
I have exactly the same problem... bit difficult to control especially when in gear..... My local LPG installers have told me it's the sensor in the exhaust... the .. is it Co2 or Lambda sensor...... The resistance changes as it gets warmer.. The LPG cuts in at a certain temperature... The two should seamlessly cross. If the sensor doesn't have a straight ramp up temp/resistance then the LPG doesn't control properly. Once this happens if you put it in neutral and hold the engine revs up around 2-3000 for 20-30 secs on mine it's enough to get past this stage.... If it is this, bear in mind yours may be a different warming process but the result is the need to change the Lambda sensor...... Mazda prices......Phew! There are plenty of suggestion for alternative sensors.... but you have to wire them in.....and so on.....

I must get round to doing mine.... only had the sensor a year in Dec........

Hope this helps
Please bear in mind this only a suggestion... could be something completely different.....

Regards
Terry

Re: Rev Worries V6

Posted: Wed Oct 17, 2012 12:37 pm
by mikeWalsall
Very .. similar to mine .. I feel while cold, if the tick over was upped, it would help especially when in stop / go / slow / traffic situations...

Strange thing is .. my Toyota switches over to gas very quickly, but I have no problems with slow / stop / start driving .. just the lack of performance compared with petrol until she is warmed up ..

Plus I use about four times the amount of petrol .. £20 only lasts me 2-3 weeks in the Bongo ..

Re: Rev Worries V6

Posted: Wed Oct 17, 2012 1:06 pm
by jojay5
I find putting the aircon on keeps the revs up enough to prevent this in mine. I switch off after 5 mins though to save fuel!