42 replies to this topic

[Bratby]

Hi all, Right Betty (Rover MPI 1993 1.3 injection Cooper)  is playing up, On Tuesday we had to bump start the car outside my girlfriends house as she was turning over very slowly but would not start. Later that eve again she failed to start however after bumping her again I've got her home.

My first suspect was the battery however this is a new battery this year (thought it maybe a alternator issue) however after charging overnight and cleaning the earths and wires on the starter/ignition coil she now turns over very quickly but won't start. I'm at a bit of a loss as to what to do next. Could this be a weak coil or starter motor although like I say she now turns over very quickly but just won't fire. Might be worth noting when we push start the car she fires up really quickly and doesn't struggle (also after it's been push started and warm it's starting again till it gets cold)

Thanks for any help in advance I've searched the forum and I know a lot of time people are saying it's a earth problem or to check these however like i say after charging the battery again she trying but just not firing.

 

Oh yeah we serviced her this year we new plugs/rotor arm/ dizzy cap/ new battery/ oil and filter so I'm ruling out these, the HT leads look in decent nick too....

 

 

[xrocketengineer]

Since the car can be bump started with no problems and now turns over quickly, the problem seems to be the earth connection for the engine. It is located on the upper steady bar between the bulkhead and the engine block above the clutch housing. It needs to be removed and cleaned on both ends or replaced. When there is high resistance on this earth path, there is a voltage drop through it due to the high current demand by the starter when cranking. There is not enough voltage for the ignition (and possibly the ECU) to work. However, when bump starting, there is no high current demand and the voltage is enough for the ignition to work.

Additionally, an extra earth strap is helpful. Connect it from one of the clutch cover (wok) bolts to the ground point by the body structural gusset between the wing and the brake servo. It is the center bottom of the picture with the black wires. Ignore the aircon components.

 

 

[Bratby]

Thanks for the reply I've just ordered another earth off eBay, it's strange I've cleaned up the earth that's on it but for £5 I'll try this and see how I get on. I'll keep you posted prob won't get around to fitting it till the weekend, thanks again

[Bratby]

Just got in from work my new earth cable came today, I was worried it looked very short so just had a quick look under the bonnet where you said to attach it to, well it looks like these is another earth that doesn't look too clever so I'm going to clean that up on Saturday and fit the new one to the clutch housing like you say. The new cable looks just long enough so hopefully that will sort her out

[xrocketengineer]

After you get your earth points cleaned, replaced or added, apply some high dielectric grease to the connections to protect them from moisture and corrosion.  

[Bratby]

Fitted the new earth as well as cleaning the old one up and no difference really. It started to rain so next port of call is going to be taking the starter apart and having a look at that. Really weird though that it turns over and tries at a good speed to start just not firing. I've had the ht leads off one by one and they all spark so I'm running out of ideas, bloody mini ha

[xrocketengineer]

Well, this is very unusual. Before doing anything with the starter, I would check the voltage at the positive side of the coil. That is the brown/purple wire coming from pin 29 of the ECU connector. I would expect to find 12VDC while turning over and when running. If the voltage is lower than that when turning over, the engine might not start.

[Bratby]

Cheers for the reply again with my work shifts this week I think it will be Sunday before I get another chance to play with the mini. I'm determined to sort her haha

[Shep76S]

93 should be Spi not Mpi

[Bratby]

My bad, what's the actual difference then?

[xrocketengineer]

My bad, what's the actual difference then?

The MPI engine has no distributor, it has two injectors, the radiator is behind the grille, it uses a serpentine type belt for the alternator, it also has a unique camshaft with no gear for a distributor and an additional lobe for a camshaft sensor and finally, the oil filter threads on directly to the block.

I figured you were dealing with a SPI since you had replaced .....rotor arm/ dizzy cap.....

[Bratby]

Cool every day is a school day, you'll all have to forgive me as I'm very much learning as I go with the mini. I'm definitely getting better as I fiddle around on the mini

[Bratby]

Hey finally got some holiday at work and had a look at the mini today I've checked the voltage from the coil off the positive side and I'm getting around 8-10 on my volt meter. Does this sound like a tired coil then? I'm a bit of a newbie with this whole thing so what coil do I need and they look quite cheap on eBay I'm thinking I'm going to order one to rule it out anyway as it's cheap?

[Bratby]

Just like to point out that. When I had the ignition on the reading on the meter was just below 12 it was something like 11.95 when I turn the car over it dropped to around 8 is this normal or I hope that's what my problem is. Oh I also took the solenoid off the starter and this all looked fine

[xrocketengineer]

That is too low when turning over. I would do the same voltage check (while turning over) at the starter battery connection. The grille needs to be off to make it easier. If the voltage is that low at the starter connection (fat battery cable) either the connections need cleaning at both ends or the cable is no good. Check also the voltage at the battery terminals while turning over. If it is that low, the battery is low on charge or bad. Maybe check this first.

 

Cheers