spi's  starts right up after sitting along time. try that with a carbed  mini. it's  not that difficult to fix your minor problem. the O2 sensor can be changed without taking any of the plumbing off the injection manifold. the vacuum leaks are much cheaper, maybe $5 worth of hoses than $1200 for the carb conversion.

I will try and track down a Scanner.  I am in Santa Rosa, California.

On a side note I have been toying with the idea of doing a carb conversion for some time.  Well before this issue.  MM and Jet Motors both have "kits" for this.  Basically a carb, manifold, fuel regulator, distributor and a relay to activate the fuel pump.  

I'm assuming that if I go that route I will not need to worry about the different sensors.  Or am I missing something?

with the coolant temp sensor , put a volt ohm meter on the two spade connecters. If you get any reading it 's good. there is  a cheap $35 universal O2 sensor that will have to be solder in . but it's better than paying $170.

The other most common issues i have run into are the potentiometer, cooling temp sensor, o2 sensor, fuel filter and the crank sensor. Unless you want to throw dollars away you are best to put it on a Sykes Picavant scanner with the spi module, not sure where you are located but maybe someone close has one.

All of the vaccum lines looked good, but I decided to replace them anyway with new line.  the trap is clean and there seems to be plenty of vaccum coming from both ports on the manifold (to the air cleaner and to the MAP through the trap).  

Still the same issue.  OK to 2,000 RPM then lots of surging.  

Do it all from above. Start at the computer then follow the lines, there are two on the rear of the intake manifold. Be sure to unclip the fuel trap and make sure air flows through it as they sometimes fill up with fuel and if so even with new elbows the computer will not get a vacuum signal and still run rough. There should be around 8 elbows in all, the vacuum line rarely fails but you can replace it with normal vacuum line if you cannot find the elbows.

Thanks Malcom.  Will do.  

Is it easier to get at the lines from above or below?  I will be installing quick release bonnet hinges while I am at it tomorrow so the bonnet will be off regardless.

The car will run better when cold as the ecu runs the car richer until it warms up, once warmed up the vacuum leaks make the car run lean and sometimes the ecu can overcome this by running richer but the outcome and running ability depends on the severity of the leak(s). Start with the cheapest thing the elbows and lines, check every connection don't think that if you find one leak there are not others. Remember the car is at least 19 to 23 years old all the rubber parts will start to fail especially the ones near the exhaust.

New clue.

I am going to formally work on it tomorrow. But, I got home early today and I thought that I would at least give it a start to see it the Mini elves had paid me a visit. At first I thought yes. The car could handle 4,000 RPM's no problem. So time for a drive. 90 seconds after starting the surging at 2,000+ RPM's started up again. Does this narrow down the diagnostics at all?

I'll check the lines.  I'll send an update as soon as I can get some time with the car. 

Chris:

I do have the SP ACR  for the ECU if it comes to that.

I have more experience with MPi than SPi, but the basics still apply, air, fuel spark with a few sensors thrown in.

Terry

The computer (even with the battery disconnected) will not re set without the SP scanner.

My SPI sat for a couple months, battery went dead and when I drove it, it acted like the fuel went bad, even though I use non-ethanol premium. Once I got the old gas ran through it ran good. Not sure if that is your problem but who knows if the computer has to sort of reset or get not pissed off from sitting?

Here is a diagram:

Sometimes people fix the problem by removing parts, so make sure all the pieces are still there.

Terry

replace vacuum elbows

As with all spi running problems check the vacuum lines first especially the elbows on the ends.

My car has been sitting for about 2 weeks (outside under a cover). It ran great then before it was covered. As a habit I started it a few times let it idle for a bit and shut it off. Today I removed the cover, washed the car and got ready for a drive to do some errands.