9 replies to this topic

[mrmeds]

I've got a 998cc which had a john cooper twin carb conversion carried out a couple of months ago. I've done about 1000 miles since ( joys of being a key worker !). its always been a bit of a sod to start from cold, which is how I remember the one i had in 1989 being !

Anyway yesterday it was harder than normal to start and then on the way home from work it started idling at about 1200 rpm rather than the 900 it had been previously

Today i couldn't get it to start at all although it was turning at starter. Checked battery- ok !     i then looked at the dizzy, cleaned the contacts and rotor arm- still didn't seem to want to start. Then took all the plugs out to see if they looked sooty, but seemed ok to me.

i put them backed and feeling a bit cheesed off, turned the key and bingo- it started first pull!!

Only downside is now rev counter says its idling at 1800rpm. !!!

 

No sign of overheating .

 

 

Anyone got any ideas whats going on ?

 

 

cheers

 

[Quinlan minor]

Is the choke mechanism working correctly/freely?

[MiniMadRacer]

Just a thought...Is the tacho reading correctly..maybe its faulty causing an ignition issue... you should definitely be able to tell an engine revving at 900 or 1800 without the need for a tacho (I am lazy, always rule out the easiest  / cheapest / least work option first)

[mrmeds]

Is the choke mechanism working correctly/freely?

yes- thats ok- got my son to pull choke in and out, while  i observed the carbs

[mrmeds]

Just a thought...Is the tacho reading correctly..maybe its faulty causing an ignition issue... you should definitely be able to tell an engine revving at 900 or 1800 without the need for a tacho (I am lazy, always rule out the easiest  / cheapest / least work option first)

was wondering, i'll listen closer today, providing i can get it to start ! although it sounded to me that it was idling  faster, it didn't sound like it was close to 2000 rpm.

[andyapanel]

I had this happen on a twin carb Allegro; it was quite exciting, in a way you don't want a car to excite you.

The carb linkage was sticking. I think I restored normal behaviour with a squirt of Plusgas.

Good luck

[mrmeds]

 

Just a thought...Is the tacho reading correctly..maybe its faulty causing an ignition issue... you should definitely be able to tell an engine revving at 900 or 1800 without the need for a tacho (I am lazy, always rule out the easiest  / cheapest / least work option first)

was wondering, i'll listen closer today, providing i can get it to start ! although it sounded to me that it was idling  faster, it didn't sound like it was close to 2000 rpm.

 

definitely fast idling, not wonky rev counter- as it ran on when i switched engine off. Could be sticky throttle cable maybe ? 

[mrmeds]

I had this happen on a twin carb Allegro; it was quite exciting, in a way you don't want a car to excite you.

The carb linkage was sticking. I think I restored normal behaviour with a squirt of Plusgas.

Good luck

will examine this possibility !

[Quinlan minor]

 

 

Just a thought...Is the tacho reading correctly..maybe its faulty causing an ignition issue... you should definitely be able to tell an engine revving at 900 or 1800 without the need for a tacho (I am lazy, always rule out the easiest  / cheapest / least work option first)

was wondering, i'll listen closer today, providing i can get it to start ! although it sounded to me that it was idling  faster, it didn't sound like it was close to 2000 rpm.

 

definitely fast idling, not wonky rev counter- as it ran on when i switched engine off. Could be sticky throttle cable maybe ? 

 

I had stayed from this subject because mine is an MPi and I wasn't sure that the same might affect a carburretted car.

Mine started misbehaving: tickover running at 1,500 RPM particularly when stuck in traffic, sometimes rising as high as 2,000 RPM. Checked everything I could think of until, on recommendation from Mike at Croydon Minis, I fitted a new throttle cable. Problem solved, never to return. £9 (at the time) very well spent!

[mrmeds]

 

 

 

Just a thought...Is the tacho reading correctly..maybe its faulty causing an ignition issue... you should definitely be able to tell an engine revving at 900 or 1800 without the need for a tacho (I am lazy, always rule out the easiest  / cheapest / least work option first)

was wondering, i'll listen closer today, providing i can get it to start ! although it sounded to me that it was idling  faster, it didn't sound like it was close to 2000 rpm.

 

definitely fast idling, not wonky rev counter- as it ran on when i switched engine off. Could be sticky throttle cable maybe ? 

 

I had stayed from this subject because mine is an MPi and I wasn't sure that the same might affect a carburretted car.

Mine started misbehaving: tickover running at 1,500 RPM particularly when stuck in traffic, sometimes rising as high as 2,000 RPM. Checked everything I could think of until, on recommendation from Mike at Croydon Minis, I fitted a new throttle cable. Problem solved, never to return. £9 (at the time) very well spent!

 

ah ! just been under the bonnet again before reading this post, the throttle cable looks a bit frayed in places, with a few strands poking out at random, could be the problem. its definitely altered in feel since i drove it out of mini sport, its got slacker.