I am just assembling my mini now and for some reason I can't get it to run right. A couple of weeks ago when I put the engine in I had it running nicely, just a little bit lean. Now that I have installed a proper fuel tank and got it almost complete I tried to start it and had a lot of difficulty getting it to run for more than a couple of seconds. I have switched fuel pumps around and even bought a new one however this has done nothing. Since the first time I ran it I have not touched anything on the carb other than changing the choke cable and putting in penrite damper oil instead of nothing.

Now when I get it to run it is running at almost 20 afr and almost dies constantly. I removed the damper while it was running and as I put it back in it would run perfectly and be around 13 afr. I removed the damper and pushed the piston down with a screwdriver and it would also run perfectly and increase rpm. It seemed like it was the piston so I removed it and checked that it seemed to be working properly.

Does anyone know what the issue may be?

Engine: 1275cc A+ Automatic (was Spi)
Carb: HS6 with a BDK needle
Fuel pumps tried:
old electric SU which happens to work and ran my van for testing
Old electric SU with new points and diaphragm
New ecco 1LM12
Ignition: locked out ducellier triggering a CB performance black box, tried timing from 10-15 degress at around 1000rpm it is trying to run at. The first time I ran it the engine ran ok with the default VW curve with 15 degrees.

_________________
1986 Mayfair (998 auto), 1974 S, 1974 Van, 1972 PMG Van

Too many minis

Do you have a fuel filter in the line somewhere?
Have you checked the fuel bowl has fuel in it now?
What spring are you using in the carb?
Have you checked the fuel bowl level?
All needles are nearly identical at the idle station, so the needle should not be the reason it won’t idle
Have you confirmed the timing with a timing light?
Is the blackbox rpm approximately the same as the timing light/tacho?

I know it’s a pain with the cb blackbox as it needs a different offset angle, but it might be worth bypassing the blackbox so you can get it running right first to eliminate one potential factor. If you time it at approximately 10 degrees of base timing, get it running and rev it up with the timing light hooked up to confirm the timing is stable and doesn’t advance or retard

Have you got a reasonably good battery & is the alternator working too? One problem I had with my blackbox (the Accuspark type) was that it didn’t work under 10v

_________________

With the current pump (ecco) I installed a ryco Z4 between the tank and pump
Yes
Red
I have not checked the actual float level, I should probably do that
Yes, when I set the timing light to the degrees the black box says it is running the mark on the pulley lines up with the first tooth. I have also checked with a basic timing light which also tells me it is correct
Yes

Yes, of course I want to avoid having to bypass the black box.

I had suspected that was the issue as I was using an old battery so I bought a new one which made no difference.

_________________
1986 Mayfair (998 auto), 1974 S, 1974 Van, 1972 PMG Van

Too many minis

That all sounds reasonable so far

Have you double checked the TDC mark on the pulley against a visual check through spark plug hole #1? Perhaps the marks are slightly different on your engine. You could also try a bit lower advance like 5-10 degrees although it should really idle either way

I’m not sure if a Z4 filter is appropriate to be fitted pre pump? It might cause an SU style fuel pump some issues as they like a gravity feed and to push the fuel rather than suck it.

If you remove the fuel hose from the carb and put the open end into a bottle is it pumping as expected with the key on?

Have you checked or replaced the spark plugs? Which brand and spec were you using?

_________________

I know that the mark is a least not far out as I tested through the plug hole when I installed the black box. I will check the timing again tonight.

The ecco fuel pump specifies that a fuel filter should be installed before the pump. I had assumed that the Z4 would be ok as it says it is suitable for mowers, motorbikes and other carburetted engines. It did however not fill with fuel until I disconnected the outlet side hose from it (even after running the pump). I don't like how this is however it didn't seem to change anything in getting it to start compared to an su without a filter.

The plugs are brand newbpr6es

I should also say this is a 1986 Rover from Japan so it has a charcoal cannister with no valve to control when it is connected to vacuum. I have tried with it disconnected and the vacuum port blocked as well as with the fuel cap off and it made no difference.


I will do more testing tonight, I am trying to get ideas before I have another look at it.

Thanks

_________________
1986 Mayfair (998 auto), 1974 S, 1974 Van, 1972 PMG Van

Too many minis

If you can add some photos of the manifold & carb when you’re working on it later that might help.

There isn’t a neutral/park safety switch in the automatic loom?

There should be small filters inside the fuel tanks, it might be worth checking without your external fuel filter just as a test. There are specific pre pump filters that have slightly less fine filtration as you don’t want to run the pump dry.

_________________

As it was running Ok before, is it possable you upset the jet when you changed the choke cable?
Maybe the choke was slightly stuck on before?

For interest,
I have run the HS6 on a couple of engines.
1410 engines with a mild cam and bit of head work.
Your needle is a little richer than the ones I have run.
But I use the yellow spring, not red. I have found red to be more typical for the HS4.

So it turns out the filter was the problem. I bypassed the filter with a section of pipe and now it is running fine. The tank is new so I am not sure it would have the filter in the tank. That means also that the two su pumps I tried are probably bad. Now unfortunately the jet hose is leaking at the float bowl.

_________________
1986 Mayfair (998 auto), 1974 S, 1974 Van, 1972 PMG Van

Too many minis

Good you've had some progress now. You've got a bit of slack in the accelerator cable, it might be worth getting it tightened up & making sure you can get full throttle at the carb with full pedal

If you look through the fuel cap with a torch you might be able to see the in tank filter if one was fitted

_________________

I just had a look and it does have the tank filter so I will replace the hose between the tank and pump so that there are no extra joins to leak onto the exhaust. I have just tensioned the accelerator cable as much as possible before it moves the throttle. It still looks loose as the linkage (and carb) are from a marina and I guess the new accelerator cable isn't flexible enough. It seems to work fine and is able to engage the kickdown.

Thanks

_________________
1986 Mayfair (998 auto), 1974 S, 1974 Van, 1972 PMG Van

Too many minis

Hi

The Su pumps may well still be good, they only push 3psi-ish so two filters in a row could be too much. Sounds like you have sorted it , but it may be worthwhile squirting some wd40 or similar around the carb near the spacer etc just to make sure it is not sucking air anywhere. I find I start leaning on things i shouldn't after being perched over a carb trying to sort out cables and the like.

The float and float level were also a problem which I have now fixed. The ecco pump is designed to be a replacement for the su so runs the same pressure. When I used the su pumps there were no filters apart from the one inside the the tank and inside the pump.

Now that I have it running I went to test drive it and none of the gears work

_________________
1986 Mayfair (998 auto), 1974 S, 1974 Van, 1972 PMG Van

Too many minis

a little more information needed here - "none of the gears work" is a bit too vague - describe what you've done, or put a video on youtube and link it

here are a couple of questions to get you started

with the engine not running and your foot off the clutch, can you put the car into gear and push the car backwards and forwards?
with the engine running and your foot off the clutch, can you put the car into gear?

_________________
did I tell you that I won a trophy?

It is an auto so I am not expecting to have many responses especially without making a new thread. This is what I have just put on an auto group and the auto mini register.

I just went to test drive my 1275 automatic (was spi) and it will not drive in any gear (forward or reverse). If I switch it from neutral to 1st it will just move forward slightly. When I bought it the bolts for the torque converter were all loose. Any ideas? The manuals I have all have troubleshooting steps for either no forward or no reverse, not both.

The person I bought the engine off had never run it in the 15 years they owned it.

_________________
1986 Mayfair (998 auto), 1974 S, 1974 Van, 1972 PMG Van

Too many minis

I have also now tested it with one wheel jacked up and it still does the same.

_________________
1986 Mayfair (998 auto), 1974 S, 1974 Van, 1972 PMG Van

Too many minis