9 replies to this topic

[vipernewz]

Car: Austin Mini Thirty

Year: 1989

Condition: mostly original - has electronic ignition fitted

 

A few weeks back my rear lights went whilst driving home and the source of this was a fuse in my alarm had gone. I replaced the fuse and then went to the car the next morning to find it would not start. 

 

I decided to get some work done that arose from the MOT and changed the head gasket as it was leaking oil. The head has been re-torqued and the valve clearances re-set. I have a compression running from radiator of; 140, 140, 150, 150 (roughly) 

 

The carb had a service as well and I took the time to convert from waxstat to fixed jet (0.90) replaced the needle (AAC) and have fitted a new butterfly. 

 

The coil and leads were old and shot so replaced those too along with some new plugs. Also changed the oil and drained the cooling system. 

 

Was having a fiddle around yesterday and noticed the spark was erratic at the plugs,  the dizzy cap was caked in crap so replaced it today and the spark is now consistent. 

 

Whilst hooked up to my old mans motor (as battery is dead) the car will turnover and idle (not brilliantly) but only with the throttle fully open, if I let off the throttle it coughs and dies. - we got it to idle yesterday and rev but has decided it doesn't want to do that anymore. 

 

Checked the float chamber and fuel is being sucked through - and the pump is definitely chucking fuel to the chamber. It doesn't matter how much I try to adjust the mixture it doesn't want to do anything. 

 

Can someone please give me some ideas as I have no clue what it could be 

 

[Zik]

I suffered a similar issue recently with the car not wanting to idle and the cause was a split breather hose from the timing cover to the carburettor allowing the carb to suck a load of clean air into the engine when the throttle was closed, weakening the mixture and thus causing stalling.

Check you don't have any leaks or splits on any hoses connected to the carb.

It may be irrelevant but have you checked the colour of the plugs? A nice tan colour indicates that the mixture is correctly set.

[Gremlin]

When you say full throttle do you mean butterfly all the way open or foot to the floor on the throttle pedal?

[vipernewz]

I suffered a similar issue recently with the car not wanting to idle and the cause was a split breather hose from the timing cover to the carburettor allowing the carb to suck a load of clean air into the engine when the throttle was closed, weakening the mixture and thus causing stalling.

Check you don't have any leaks or splits on any hoses connected to the carb.

It may be irrelevant but have you checked the colour of the plugs? A nice tan colour indicates that the mixture is correctly set.

 

Checked the hoses and they all look ok (old but ok), no splits etc. might try replacing them just to rule it out anyway - the plugs are black atm but they have been running full choke and not actually ignited properly to day. 

 

When you say full throttle do you mean butterfly all the way open or foot to the floor on the throttle pedal?

 

I mean butterfly. 

 

Also forgot to mention yesterday after it was idling I decided to see if any of the breather pipes being removed a difference (helped once before with dizzy issues). After the engine had been turned off and sat for a little there was a white smoke coming from the carb where the breather pipe comes off to the tappet chest cover. 

[minimadles]

Have you checked to make sure that it's the correct cap and you have the leads on in the correct firing order

[vipernewz]

Have you checked to make sure that it's the correct cap and you have the leads on in the correct firing order

 

Cap is an exact match to the one I took off which had been on there since I bought the car. I marked each of the leads when I done the gasket change then replaced one by one... and they were replaced one by one when I changed the cap over. 

[Stu.]

From what work you have recently undertaken, it sounds like either of the following to me  -

 

A vaccum leak to the gaskets between the carb and manifold or manifold to head.

 

 

There are three to go in between the carb and manifold.

 

I could not get mine to start for a week after trying everything. I eventually thought about a vac leak, so sprayed some WD40 around the carb to manifold gaskets to seal any minute gaps and she fired straight away. I changed the gaskets and she's been cracking since. I coud not believe such a small vac leak could prevent the engine from starting !

 

I'm not suggesting you use WD40 to seal as its flammable, but it worked for me. You can buy vaccum leak sealant, so it may be a bit safer ??

 

The only other thing I can think of is maybe an issue with the carb set up or idle adjuctment if you have overhauled it etc ??

 

Let us know how you get on ............

[Cooperman]

Does it run with full choke? If it does, then you have an air leak.

[vipernewz]

Sorry for taking so long to get back my wireless has died so been trying to fix that!!

ordered up some bits and bobs which arrived today gunna fit everything at the weekend and see what happens. Got some new gaskets for carb to manifold and also got a new tappet cover with breather as it was long worse for wear...

cooperman- it only just about runs with full choke and butterfly fully open, however it had its moments where it worked fine then slowly died off and didn't want to start again. Not sure if it is a small leak that seals for a bit then re-opens??

Edited by vipernewz, 04 December 2013 - 06:02 PM.

[vipernewz]

Ok so new gaskets fitted, the new ones where slightly thicker than the ones I took off... Also fitted the new tappet cover and breather hose.

the car will now idle but there is a flapping noise from the exhaust, popped my hand over to see if it was chucking out any fuel which it wasn't however it felt like there was a lot more pressure than normal.

even though the car will idle, it won't rev properly it picks up slightly when you open the butterfly but nowhere near what it should be... Could this be something to do with timing?