24 replies to this topic

[Minimoo84]

Hi,

 

I've been having terrible trouble cold starting my mini, I can be turning it over (not continually but bursts) for quite a while (I'm guessing a good 5 mins). It turns over, you can smell fuel but it just won't fire. We've checked there is a spark etc, checked the plug gaps, tappets have been checked.

 

Over the last couple of months having more time with COVID work changes (not necessarily due to this but replacing unknown second hand bits with new) I have changed:

 

• SU mechanical fuel pump (with a genuine Burlen one)
• Distributer (123 Tune) (Made the jump to electronic ignition)
• Coil (to go with above)
• Plugs (service at service time as the ones that were in it came with the engine in boxes when I first built the car)
• Battery has been fully charged on a mains charger
• Starter motor

However none of these have changed the start. I'm clutching at straws but could I have the inlet and overflow on the carb the wrong way round? Could it be something silly like a bend in a pipe been to tight restricting flow? Once the engine is 'warm' it starts fine.

 

If any one has an wise words as to why my Mini won't start they would be gratefully received. 

 

Thanks in advance

 

John

[Maccmike8]

You say cold starting, does that suggest you get it started when its hot?

Since it last started normally, have you carried out any tweaks, mods or refreshing?

Could you have altered something such as the carb?

Upload a picture of your carb.

You need air, fuel, ignition and compression for the car to run.

You have certainly got ignition so, so long as you have the plug leads in the correct order its probably safe to say this isnt the fault.

That leaves the carb and compression. 

A compression checker is cheap and easy to test. If thats ok then it would point fingers to the carb.

You mention have the overflow on the wrong pipe, why have you had this off?

[Minimoo84]

Hi I did a compression test the other week and all was good.

 

I will try checking the overflow.

[kit352]

What were your compression numbers?

This may sound silly but are you using the choke and is it opening and closing completely?

[Minimoo84]

compression was 130psi on all four bores. yes choke is working

[PACINO]

Hello! I have had that problem. Could you tell which carb you use? What coil have you fitted to the 123ignition?

It can be several things. Badly dizzy setting. Spark plugs too cold (which ones do you use?), insufficient fuel (pump) or a knockout carburetor...

[Maccmike8]

Does it start at all?

Compression is great.

That leaves fuel feed or carb.

Can you measure the fuel pressure?

[PACINO]

Hi. Part by part; for me, at least in carburetion, the NGK are the spark plugs that work best. And I've used Champion and Bosch, but NGK giving me the best performance. I use a 123ignition, but I don't know how you have made the setting or what curve have you chosen. My coil is a BERU ZS106. Primary resistance: 3.3 ohms (Ω).

The flow of petrol coming out of the pump can be measured. You can adapt a filter with a pressure gauge (Malpassi Filter king type) before the carburetor inlet to see if the PSI flow is correct.

[Dusky]

Let's get back to basic here.
Do you have spark?
Do you have fuel inside the bores?

If yes: do you have enough fuel/ not too much?
Do you have spark at the right moment?

I'm.sure one of those 4 questions will be answered with a "no".

[CK's mini]

How old is the fuel? I parked my mini up for a couple of years, when I tried to recommission it for the road it wouldn't start, New fuel and hey presto. ?

[Minimoo84]

Hi all thank you for suggestions life has been a little crazy so not getting on here often. I have NGK spark plugs in I will get the type number. Fuel is fresh shell v power. Definitely have spark as we checked that last time we worked on it. There's a tight bend in one of the soft fuel lines I wonder if it's collapsed to much internally - new pip on order.

[Minimoo84]

Hi all thank you for suggestions life has been a little crazy so not getting on here often. I have NGK spark plugs in I will get the type number. Fuel is fresh shell v power. Definitely have spark as we checked that last time we worked on it. There's a tight bend in one of the soft fuel lines I wonder if it's collapsed to much internally - new pip on order.

[Dusky]

Hi all thank you for suggestions life has been a little crazy so not getting on here often. I have NGK spark plugs in I will get the type number. Fuel is fresh shell v power. Definitely have spark as we checked that last time we worked on it. There's a tight bend in one of the soft fuel lines I wonder if it's collapsed to much internally - new pip on order.

Try starting it with starting fluid ( startpilot or similar). That'll establish if it's the fuelling or timing. Although if a fuel hose has a tight bend it might indeed be collapsed.

[PACINO]

Could you tell me which advance curve you have selected at the dizzy? A couple of 'photos' of the engine and knowing which coil you have adapted would be fine.

[Minimoo84]

So we have an electronic fuel pump in place of the mechanical one at present. Car now starts after a couple of goes of turning over. Had its MOT on Friday and it was running incredibly rich (off the top of the scale at 9.99) we turned the mixture down and got it stable at 3.8% CO and it acutally run much better on the way home, could been too rich have impacted starting?