18 replies to this topic

[Styleegeeza]

Hi,

Just brought a classic mini sprite in red 1993, and want to attend the Santa pod mini show this Saturday, however it idles fine no lumps and sits nicely at around 800rpm, however when you pull away it sort of stutters and you give it more revs but it sort of kangaroos a bit then it surges and pulls well up through the rev range, change to second and a similar thing happens but not as bad.

It is worse when the engine is cool, and get better when fully warm haver not perfect, I checked the vacuum advance pipe and was split so I replaced it completely But it is the same and did not correct the problems.

Anyone any ideas as to what it could be and a fix?

P.s it's a carb model with a choke.

[ste3po]

I had a similar problem with mine when I fitted a new distributor, how is the advance set up on that? As could relate to a timing issue. Seeing as you have ruled out the vacuum, will assume that's not the issue but again with mine the pipe was connected correctly but just hadn't been pushed in enough so wasn't doing a lot.

 

Maybe try advancing the distributor, I did with mine and fixed the problem perfectly.

Could be a few other things but reading your post, it sounds like the exact same issue I had.

[KernowCooper]

Sounds as though the fuelling after idle is weak, either its set really weak at idle, or the engine may have the wrong needle? I'd be checking the mixture but only after you have done Tappets/Plugs/Points if any? and timing. 3% CO at idle or use the lifting pin revs slightly and resettles = OK dies away and stalls to weak, revs up and stays there to rich. Is the car standard ? No Cone filter or performance exhaust?

Edited by KernowCooper, 05 August 2014 - 09:09 AM.

[cal844]

The OP'S car will have an HIF series carb if the car is standard

[bloke]

A common problem if this is an SPI. Replace the distributor cap and rotor arm, and all will be good. I had to do this on the last five minis I have owned, many times, try to get original or Lucas parts if you can, as these produce the best contact areas. Also had to do the same to mums mini, which was suffering the same problem, and that had a HIF 38 carburettor, being a mini Rio.

 

All the very best from Bloke.

Edited by bloke, 05 August 2014 - 10:31 AM.

[Styleegeeza]

Hi, thanks for far but I am a novice when it comes to carbs and distributors (had loads of minis but love driving and looking at them, my knowledge is limited however well chuffed today as fixed the dodgy electrics!) so should be able to attend sata pod this weekend!

O.k how do I check my advance, and how do I know if it's right and how do I advance it if it's wrong?

3% co (sorry not sure what this means!) and lifting pin again what's this and how should I check it, lastly I know there is a screw to make the carb richer or leaner but where is this and then do I need to change anything else?

Sorry to sound a complete newbie, I am trying to sort myself instead of taking to a garage! (And learn at the same time

[RosieSprite]

Styleegeeza I also have a red '93 Sprite. The same thing happened to me tonight for the first time! Did yours feel as if it was going to stall when you came to a stop? Also get a sharp "cough" exhaust note when accelerator is released? 

 

Tom

Edited by RosieSprite, 05 August 2014 - 10:29 PM.

[ste3po]

Well from newbie to newbie this can only go well ;)...

When I had a similar issue to yours the only thing that had changed was the distributor so I knew that was most likely the issue. Now I don't have specialist knowledge nor top grade tools, but I do like to be hands on and try if things work.

To advance the distributor all I did was loosen the bolt off slightly (do this while the car is not running) that holds in place the bracket of the distributor - loosen it a little at a time until you can just about move the distributor by hand - to make sure you can move it by hand just turn the distributor a very small amount a mm at most, try and move it back to where you had it.

Basically the distributor just moves in a circular motion, so NO need to pull at it. Just to point out at this point do not disconnect any wiring or the cap. I had to remove my grill in order to get to the bolt a bit easier.

Once you have the distributor loose enough to just be able to move it you can then start up the car (make sure to only have loosened it just enough to move it by hand, having it too loose could cause issues).

Once you have the car going, at a reasonably good temp and revs, you are ready to move on... If the car is not at continuous revs then this could make it a little harder, I made sure the revs were constant and had the choke all the way in.

Now go to your distributor, at this point BE CAREFUL, keep anything out of the way of moving parts. What you should notice if you start to turn the distributor slightly the revs will either increase or drop, for myself because I still needed to advance the distributor so I was turning it clockwise in very small increments, listen very carefully to the revs. What I looked for was getting to the point where the revs were at their highest. To find this i kept turning the distributor until the revs started to drop again, then turned it back anti-clockwise to get to the point where the revs were highest again. This can take time, just make sure you can hear as best as possible... (No music, other people talking... you know). Just to add be careful of pulling any wires when turning, some of the wiring from my distributor to coil were quite short so I had to move the coil a little too (Hopefully you won't have to).

 

Once you think you have it set up in the correct position you'll want to tighten up the bolt again, I did this with the engine off just to eliminate the chance of me injuring myself or damaging the car. Obviously when tightening the bolt try not to touch the distributor itself.

When everything is back in place (including the grill if you removed it). Start up the car again (hopefully starting without issue). To see if I had set it up right I then took the car for a quick spin as I lived next to a road that was rarely used so could test it out. So if this has removed the problem or at least made it better then great! After taking the car for a spin and noticing a 'good' change you may want to start the process again to see if you can get any better results.

After I had done this, and driven for a while I got the engine tuned properly and the timing set up correctly too, you can get close with the above method but it's not going to be perfect. This cost about £50 to get a mobile guy to come round and set it up 'Professionally' for me.

Really hope this helps, as said newbie myself but tried to keep it simple with as much detail as you need.
Any questions just ask, if I can't answer then one of the Gurus is sure to show up... a couple have already posted above...

Good Luck!

 

[Styleegeeza]

Ok thanks very much I am going out in the sun to do it now on my mini! Also might try turning the mixture up too a bit if not solved then I guess I can just turn it back a bit

Thanks for the advise in simple newbie speak

One last thing, where do I find the mixture screw on my card and which way do you turn to make richer (also I take it I have to remove the standard air filter to get to it (can I run the engine at idle while increasing the mixture level with out the air filter on?

Thanks again everyone!

[Styleegeeza]

Update, before checking the timing I increased the mixture screw on my carb by about a complete turn and (fingers crossed) it seems to have virtually sorted the problem "note" engine was fully hot by then so going to let it cool down and try from cold?

If much better I will give it a quarter turn and hope that solves it completely.

I have also sorted my electric problems out so looks like I can go to Santa pod this weekend!!

Thanks all for all your help and advise for a complete newbie!

[ste3po]

Sounds good! Well Done! And welcome to the world of minis!

[KernowCooper]

I suggest you get yourself a workshop manual and have a read, it will pay for itself in no time

[RosieSprite]

Thanks Ste3to!  Im going to let my local Mini specialist have a look on Friday as myself and mechanics do not mix lol I don't trust myself. But thank you anyways it was good of you to take the time to explain to me!

 

Tom

[Styleegeeza]

Update - o.k mini NOT FIXED! When she is cool she does the same thing even though I have increased the mixture screw.

Seems to be really bad when cold but much better when hot, noticed there is a very slight popping note through the back pipe too?

I am guessing next thing to do is the timing advance on the distributor, is the best way to do it how ste3po has suggested e.g loosen the distributor screw then run engine turn one mill at a time while listening for highest rev, then turn off and tighten up?

Thx

[ste3po]

Sorry to hear that! Wait to see if anyone else has a better run through of the distributor advance (as said the method I have suggested may be a fairly quick job but will definitely not be perfect).

In terms of the popping from the back pipe, sounds like a missfire and it could be a few problems, again could be linked to the timing. Just check your distributor cap on the inside just to see what it is like. As when I had a similar 'popping' the cap was causing a sort of missfire due to a bad connection, this was found to be the small piece of carbon (It was damaged and had come loose so wasn't creating the best connection) in the center of the cap that then links up to the center HT lead and through to the coil. I had a few spare caps so just switched them over and it sorted the problem. When doing this try not to remove any wiring like HT leads, only as then there's the chance of not going back in the right order but that's easy to sort anyway, plenty of posts about running orders :)

Good luck again!