24 replies to this topic

[Timmyquick]

Hi finally started mini this week after part engine build and body shell all thanks to members on this forum, however I have a problem.

For the first start of the day it won't start. It's a fuel problem, as soon I put a mist of petrol in, it starts, runs perfect, idle is perfect. I can then leave it a few hours, go back to mini the same, starts perfect. Next morning however back to no fuel, put a mist of petrol through air filter all is good.

It's a 1275 bored 30 tho over. Evolution cam, BDL needle HIFF44 carb, this is the sticky point. I posted previously on here ( don't know how to link to it?) about the carb and turns out it was a maestro/montego carb, but used it anyway. I did away with the electronic valve and made 2 plates up to keep the passage in carb to what it would be set at during normal driving so no fuel is reduced on coasting. It already had a manual choke conversion done to it. It all seems fine apart from this starting issue.

Facet fuel pump is working great.

Timing set correctly to a recommendation on a previous post in this forum with same spec. But can't remember what that was! Did it a while ago, think it may have been 6 degrees, (this was off a temporary tank bottle hanging from ceiling) now got a petrol tank in boot with facet pump.

Could this be low fuel float level? Though I did set it to what the rebuild kit instruction said.

https://imgur.com/a/e23w0Of

Edited by Timmyquick, 06 February 2022 - 02:26 PM.

[sonscar]

Not familiar with HIF carbs other than having seen one I would check the choke operation.Steve..

[Timmyquick]

When I did a tune using Gunson colourtune it all looks good, choke on it richens mixture, idle speed increases. It literally like no fuel on first engine start for the day.

[Tornado99]

Any chance of a fuel filter or tank sieve issue? What about tank venting (at the cap or on the neck vent pipe if it has that)?

[D 'n A]

I would check the float levels of the carb first.

Does it not start no matter what you do? Does it only start when you put fuel in through the filter?

When an engine gets hot the heat of the exhaust can evaporate the fuel in your bowl of the carb. This combined with a to low fuel level could cause this problem.

Also, does the facet pump generate the right pressure for your carb?

[Timmyquick]

Thanks for replies.
Tank is a vented one with non vented cap. I cleaned tank out on cement mixer with phosphate acid for a day which destroyed the internal filter so removed it with great difficulty! It don't come off easy. Vent is fine can blow through it no problem. Facet pump from mini spares with filter. I have no means to check pressure but is supposedly the right pressure for road car carb. Lots off fuel on pipe to carb. It's literally the first start from cold after the previous day it won't start. The effect of spraying a mist off fuel into air filter intake is immediate that why I come to conclusion it gets no fuel when left for 24hrs on a cold start. However it can start without assistance but I end up cranking for literally minutes. Have also checked the anti run on valve and that appears to be working fine. No vacuum leaks or I couldn't find any. I can literally start it hours later no problems just the first start after a day. I will try and start car tomorrow after work with no petrol cap on tank, had not thought off that. Don't fancy taking carb off again to mess with float level as I find it a pig! And is running great from what I can tell. I have not driven it yet as it's unfinished yet, no doors bonnet or boot yet. Only driven a few yards on my drive in first gear and reverse. All seems good so far apart from this starting issue.

[richmondclassicsnorthwales]

Hi

 

Doesn,t seem you are far off the mark here getting this running.

 

With out going down the spending money after money exercise, try these couple of simple steps first to get you to the correct ball park.

 

Get some Easy Start or Start Ya Bastdra - it's good gear and can help a lot.

 

Spray this up the carb intake just before you want to start the car, say a 2 second - 3 second spray, get in the car and go for start as you normally would.

 

If the car starts, you have answered the fuel air / mixture / start ratio if it runs nice and neat once running

 

The carb must have been the electronic valve choke and these were a pain in the rectum after about 65.000 miles on the standard cars they were fitted to.

 

When you say about putting 2 blanking plates in the valves place, did you put a gasket to stop any air seeping in ?

 

Remember, the weather is cold - that don't help - next, petrol has to be really fresh - and thirdly, you have 10% ethanol I suppose in the fuel

 

These are not the best winter starters for a Mini,

 

Minis liked 97 or even 98 Octane Ron petrol, not the mierda y mierda gasolina de hoy at 92

 

Could be just a little tweek of a mixture screw

 

Idea is only again an idea for the pot....  Not set in stone

[cal844]

Hi

Doesn,t seem you are far off the mark here getting this running.

With out going down the spending money after money exercise, try these couple of simple steps first to get you to the correct ball park.

Get some Easy Start or Start Ya Bastdra - it's good gear and can help a lot.

Spray this up the carb intake just before you want to start the car, say a 2 second - 3 second spray, get in the car and go for start as you normally would.

If the car starts, you have answered the fuel air / mixture / start ratio if it runs nice and neat once running

The carb must have been the electronic valve choke and these were a pain in the rectum after about 65.000 miles on the standard cars they were fitted to.

When you say about putting 2 blanking plates in the valves place, did you put a gasket to stop any air seeping in ?

Remember, the weather is cold - that don't help - next, petrol has to be really fresh - and thirdly, you have 10% ethanol I suppose in the fuel

These are not the best winter starters for a Mini,

Minis liked 97 or even 98 Octane Ron petrol, not the mierda y mierda gasolina de hoy at 92

Could be just a little tweek of a mixture screw

Idea is only again an idea for the pot.... Not set in stone

Some good ideas there, I do agree that it is a fuel issue, I also advise not to rely on the easy start solution, the engines don't like repeated use over a few weeks (if starting it every day for a few weeks, it can cause issues).

Has the OP filled the dashpot with 20w50 oil as per a factory set up (if fitted)

Edited by cal844, 06 February 2022 - 08:58 PM.

[Timmyquick]

Thanks for info.

I put £30 of fuel in tank, super unleaded 99ron £1.61 a litre! So it's E5

When I purchased pump I got SU dash pot oil, also filled to correct level.

Think it was Richmond classics who posted on a previous post about my carb. From this I figured out what ports are normally connected with valve in normal position ( no fuel being saved or reduced ).

I then made an aluminium plate which connected the correct ports together for this to occur ( drilled and filed plate). Then my blanking plate on top. I made 2 gaskets with decent gasket paper and bolted on where valve was ( the valve was knackered, seized and seal dried and cracked) plus I had 4mm plate knocking around. Though I did figure out if valve is in good condition and no power that would have been the correct setting.

I found a rover video training video on YouTube on what position the choke would be if it had original stepper motor on carb so holes line up where they should when I use manual choke.

I only wish I had taken photos! I generally being doing this in garage after kids gone to bed and I forget.

[mk1leg]

I had a brand new HIF44 and kept getting fule starvation probs so I stripped it down and founf that the plastic tube was partically blocked with swarth from moulding clean down

[Timmyquick]

Got a few ideas to try for tomorrow after work. Will update if I have any success or failure!
Thanks everyone.

[Steam]

It sounds a lot like the choke enrichment and idle increase is not working correctly.
That fault will give those symptoms as well as low or no fuel in bowl.

[Aaran13]

I used the SU oil when I rebuilt my HIF38 recently. Couldn’t get it to run (different issue to yours though). Replaced the oil with 20w50 and a huge improvement so may be worth changing to avoid further problems down the line…

[cal844]

I used the SU oil when I rebuilt my HIF38 recently. Couldn’t get it to run (different issue to yours though). Replaced the oil with 20w50 and a huge improvement so may be worth changing to avoid further problems down the line…

I can never get a mini to run on anything except 20w50 oil in the dashpot

[Timmyquick]

Well I have had a partial success.

Had a thought whilst wide awake in bed last night! Mini keeps me awake.

Originally this carb had a vacuum controlled switch, linking 2 ports on the carb. That was also shot plus I ran out out of vacuum ports on manifold.

I simply joined them together with vacuum hose. My eureka moment last night and the replies on this post, was realisation what I have done is seriously weakened the mixture when the choke is activated and the circuit through these two ports are completed.

Today I have replaced this vacuum hose link and capped them off. Hopefully you can see in this picture.
https://imgur.com/a/7UoSBC3

This seriously richens the mixture here
https://imgur.com/a/WXQfaMq

This is the aluminium plates replacing the Orfco valve
https://imgur.com/a/YiUEZJp

Engine fired up straight away from cold with this change. Unfortunately this has messed my previous mixture and idle setting up when choke on, so got to mess around adjust choke cable and a tweak off the mixture screw.

What I'm wondering now is, should I get a replacement vacuum switch to replace the original? They are still available, or just tweek a bit with this setup and see how it goes? I do believe the vacuum switch only has an effect by restricting and increase the air between these 2 ports when choke is in use by manifold pressure.

Also curious about using 20/50 oil in dash pot over SU oil. What's the difference in viscosity? Is thinner or thicker oil best?

Edited by Timmyquick, 07 February 2022 - 02:56 PM.