15 replies to this topic

[SurreySprite]

Good Morning all,

I am going to view a 1994 Sprite with the original 1275 injection engine this evening.

I am not very familiar with the injection models so was wondering if there is anything in particular i should be looking out for?

The car has only done 36K miles.

Any pointers will be greatly appreciated and i will let you know how i get on.

Thanks,
James

[Guess-Works.com]

Bodywork, bodywork, bodywork.....

als this is a good guide.... http://www.itsamini.co.uk/check.htm

[SurreySprite]

Bodywork, bodywork, bodywork.....

als this is a good guide.... http://www.itsamini.co.uk/check.htm

Thank you for your response. I am familiar with the tendency towards a spot of rust I will take a look at the link.

I don't know much about the injection engines so was just wondering if there is anything i should specifically look for.

James

[rozzer1275]

engine wise all the usuals as carb mini, but it should start real easy from hot or cold with no accelerator, no missfires or hesitation. may be worth getting it to a garage for emmisions test.

[DaveRob]

The better option if you can get it is to have an ECU with a single plug in... the SPi minis came with a 1 plug or a 2 plug depending on model. Make sure the immobiliser either works properly or is disabled........ if it isnt used but the engine starts then this is ok..... if it is used then make sure you have the fobs and they are in good nick cause the ECU is coded to the imobiliser.... consequestley the ECU AND immobiliser must be changed out as a pair if issues arrise. I think, ( not totally sure but someone might enlighten), if you have a 2 plug ECU then ECU is matched to the immobiliser. If you have a single plug ECU then they operate independantly but the immob still sends a code to the ECU to start. also I think the 2 plug ECU system uses a swuitch on the accel pedal to indicate to the ECU that the pedal is pressed...with a single plug job the ECU gets its accel info from the TPS sensor. consequently using a single plug eliminates a posible fault cause as you wont have an accel switch to worry about.

Make sure that the coolant gauge gets to the middle line on the gauge.... if it doesnt the its either faulty thermostat or a good chance the CTS if goosed.... these cost about £45 but are a royal pain to change as all your inlet manifold has to be taken off to get to it.

Check the MAP tubes from the back of the throttle body, make sure that they are in good nick and all the rubber elbows are not perished. their are 2 tubes one goes to the air filter the other, ( on the left as you look at the TB from the front ), goes to the ECU MAP sensor port. it goes via an oil trap on the left bulkhead. Check all the mount bushes and oil leaks... check the gearbox at the diff and the rod change for leaks. take the plugs out if you can and make sure they are the right colour....... Im sure their are loads of other things but Ill add some if I can think of them later.

Hope this helps

Rob

[rozzer1275]

The better option if you can get it is to have an ECU with a single plug in... the SPi minis came with a 1 plug or a 2 plug depending on model. Make sure the immobiliser either works properly or is disabled........ if it isnt used but the engine starts then this is ok..... if it is used then make sure you have the fobs and they are in good nick cause the ECU is coded to the imobiliser.... consequestley the ECU AND immobiliser must be changed out as a pair if issues arrise. I think, ( not totally sure but someone might enlighten), if you have a 2 plug ECU then ECU is matched to the immobiliser. If you have a single plug ECU then they operate independantly but the immob still sends a code to the ECU to start. also I think the 2 plug ECU system uses a swuitch on the accel pedal to indicate to the ECU that the pedal is pressed...with a single plug job the ECU gets its accel info from the TPS sensor. consequently using a single plug eliminates a posible fault cause as you wont have an accel switch to worry about.

Make sure that the coolant gauge gets to the middle line on the gauge.... if it doesnt the its either faulty thermostat or a good chance the CTS if goosed.... these cost about £45 but are a royal pain to change as all your inlet manifold has to be taken off to get to it.

Check the MAP tubes from the back of the throttle body, make sure that they are in good nick and all the rubber elbows are not perished. their are 2 tubes one goes to the air filter the other, ( on the left as you look at the TB from the front ), goes to the ECU MAP sensor port. it goes via an oil trap on the left bulkhead. Check all the mount bushes and oil leaks... check the gearbox at the diff and the rod change for leaks. take the plugs out if you can and make sure they are the right colour....... Im sure their are loads of other things but Ill add some if I can think of them later.

Hope this helps

Rob

Yer the single plug ECU is linked to the alarm/imobliser, I have changed a single plug ECU without changing the imobliser, by cutting one of the multi plug wires (cant remember which one will have to look) and the imobliser still worked.
so it maybe posible to change imobliser too buy cutting the same wire, i have never tried.

[SurreySprite]

Thank you for your reponse, it is greatly appreciated. Certainly some things to be looked at.

I have just discovered that the Sprite only has 50 bhp as it injection. Tuning an injection is obviously alot more difficult / expensive. Would i see a rise in bhp/torque from a stage 1 kit?

[DaveRob]

you might check my 100BHP thread...lol

http://www.theminifo...x...=79995&st=0

Rob

[SurreySprite]

you might check my 100BHP thread...lol

http://www.theminifo...x...=79995&st=0

Rob

Hi Rob,

Great post although i am not looking (yet) to get that much power.

I would only have £200 - 300 to spend on tuning so i thought a Stage 1 kit would fit into my price bracket. My only question is whether this will actually give me a performance increase on an injection 50bhp Sprite engine.

[DaveRob]

Maybe the easy way to approach this is to get hold of a cooper head and cam....... I sold one recently to blackbelt1990 on here.... if he isnt using it maybe he might want to deal...... that, ( assuming you get your CR to about 10:1 ) should get you to 63BHP..... then fit a KandN.... or fit a stage 1 head K and N and a 274 scatterpattern cam with an LCB to a rc40.... just make sure your exhaust manifold is for an Injection car..... ....... that should make a start.

Rob

[SurreySprite]

Maybe the easy way to approach this is to get hold of a cooper head and cam....... I sold one recently to blackbelt1990 on here.... if he isnt using it maybe he might want to deal...... that, ( assuming you get your CR to about 10:1 ) should get you to 63BHP..... then fit a KandN.... or fit a stage 1 head K and N and a 274 scatterpattern cam with an LCB to a rc40.... just make sure your exhaust manifold is for an Injection car..... ....... that should make a start.

Rob

Sounds quite tempting although i don't think i would want to do that for a while. Would you say that fitting a stage 1 before changing to the cooper head and cam is pointless then?

[John H]

The Cooper ECU also makes a difference. Sold mine to a chap in the USA with a Sprite and he says the change is remarkable!

[rozzer1275]

you might check my 100BHP thread...lol

http://www.theminifo...x...=79995&st=0

Rob

Hi Rob I enjoyed reading your injection tuning thread, i did consider a simular route myself some years ago, out of intrest I have a few questions/suggestions for you, for give my if i'm telling you to suck eggs.

You said about using a modded ECU what exactly do you mean, has it been remapped?

274 cam how are you going to deal with the vacuum, the lower vacuum may give problems with emmisions at idle.
you can dampend the vacum pulsing with a small vessel the injection vapour trap helps.

I did alter fuel pressure by shimming the standard fuel pressure regulator.

I tried porting the SPi inlet manifold and found that removing the lugs gave fueling problems between the inner and outer cylinders.

I also reshaped the throtal body to inlet plastic spacer and reshaped the butterfly shaft.

[Sprocket]

274 cam how are you going to deal with the vacuum, the lower vacuum may give problems with emmisions at idle.
you can dampend the vacum pulsing with a small vessel the injection vapour trap helps.

The 274 and 274SP are specificaly designed for the injection engines to reduce the effects you describe. The 274SP I have fitted to an engine did show a lower idle vacuum, but it was still in the 500mmhg region, just, I suspect a slight error in crank sensor positioning however which would contribute to the lower idle vacuum.

[DaveRob]

Forgive me if I dont know how to work this "quote" thing lol


You said about using a modded ECU what exactly do you mean, has it been remapped?

No ... its a standard Rover MEMS ECU.....its just not the Mini one.... the single plug loom fits pin for pin compatable to the Rover 16 valve METRO GTa ecu.... this ECU is mapped for the original cars 106 BHP and a bit more and takes all the same sensor inputs. When I get this thing on the rollers Im going to compare the performance of the std Cooper ECU to this one.

274 cam how are you going to deal with the vacuum, the lower vacuum may give problems with emmisions at idle.
you can dampend the vacum pulsing with a small vessel the injection vapour trap helps.

See Sprokets reply above..... by the way all kudos to Sproket for his help and advice during my rebuild

I did alter fuel pressure by shimming the standard fuel pressure regulator.

I do anticipate presure regulator changes

I tried porting the SPi inlet manifold and found that removing the lugs gave fueling problems between the inner and outer cylinders.

This is always going to be an issue with siamese inlet ports .... this charge robbing effect is well detailed in Vizards bible....

I also reshaped the throtal body to inlet plastic spacer and reshaped the butterfly shaft.

The butterfly shaft is also well detailed in the "bible".... Ill be reboreing the TB and doing the reshape on the shaft

As to the "sucking eggs" thing......... Im here to be educated lol.... open discussion and information sharing is a sure fire route to advancements in knowledge... their are always experts who say "everyone knows that".... Its the engineering pioneers that make sure everyone knows what everyone else does.........

Thanks

Rob