new mpi engine wont fire. please help
Turbo Mini Forums

Hi, iv just put my new engine into the mpi

Just tried to start it, it turns over but doesn’t fire into life.

The engine has had a rebore, new piston rings, new valve guides, sw5i cam and new followers. The battery is on the flat side, we will try to jump start it with the 306 after tea.

Failing this, does antone have any ideas? We have a spark and fuel getting the the cylinders.

I used the sensors off the donor engine which may not have been such a good idea.

Also, they flywheel can only go on in one position due to the keyway.

If it doesn’t start with a jumpstart im not sure what to do next apart from change sensors

thanks

Cam sensor connected?

Coolant and air temp sensor conneced and in good condition?

Plug lead firing order correct?

New AP clutch?


One thing to consider is that if you are sure fuel is getting to the cylinder and you have beenn trying to start the engine for a while, tthe cylinders may well be flooded.

cheers for the reply sprocket. still no joy. am aware of the flooding situation. this isnt the problem.

the clutch is an ap clutch fast road(new), what does this mean? do mpis somehow not get on with them?

the cam sensor is connected. i have changed this for one that is known to be working. have also changed the flywheel sensor to a known working one. all other sensors are connected

have changed the plugs. have spark tested. the leads are on the right plugs

have removed and cleaned up the engine earth, and replaced.

dont have coolant in the system at the moment, am waiting for it to fire up, when i know it will i will then refil. does this matter with an mpi car?

have also had a timing light on it and it seems fine.

the machanical timing was checked by 2 of us when building the engine.

it seems as though there is a problem with the imobiliser (this is how i can best describe it), whereby the engine turns over then fires from time to time but not starts?

the spec of the engine is as follows if this helps?

mpi block bored to 1360.
new pistons with hastings rings
standard crank with new standard bearings
sw5i cam with followers, piper duplex vernier timing (yes i did tighten the bolts when times correctly)
comoression ratio is around 10.7:1 - on the high side i know but i have run that cr on this car pervious.
also running 1.5 roller rockers - might it be that they are providing too much lift along with the cam?

may have some diagnostic equipment coming tomorrow, so will see if that shows anything, before i have to fork out cash to take it somehwere.

failing electronic problems, i will have to take the cngine apart again, check timing etc, if its ok (aas i know it is) i may just have to put a standard engine back in. im really not sure what else there is to check.

if anyone has any ideas?

Can't offer enlightenment, I'm afraid, but would be interested in what the problem turns out to be - I run an MPi.

Good luck!

also had new thermostart(correct temp), oil pump, water pump and fanbelt (cant see how these would effect the running of rhe car..)

the ap clutch mounts at a different angle and throws the timing off.

see the diagram in this link.

http://www.minimaniauk.co.uk/web/SCatagory...99/ArticleV.cfm

Have you got the flywheel on the wrong way round?? (roitate 180 degrees so that the sensor reads TDC at the wrong time)

ok...i really hope thats the problem as im clutching at straws at the moment. whats in there at the moment is the slightly smaller diameter pre verto plate, as this is all i had at the time (fast road ap).

will get on the phone to minispares in the morning and ask for 24 hour delivery on one...

ap, i think that the flywheel can only go on in one place due to the offset keyway

the flywheel also has two sets of sensor cutouts in on it.

cheers everyone for their input. its a relief to have found the potential problem. will look at this tomorrow and friday and keep this post updated. many thanks

what my engine is presenting with at the moment would be as if the wrong clutch was fitted? does anyone know if there is a fast road injection compatible clutch plate?

dosent matter about the friction plate, its the pressure plate that causes the issue.

ok. well im using a pressure plate removed from an mpi engine, so looks like clutch may not be the problem?

Edited by welshdan on 18th Nov, 2009.

just a thought, can you fit the pressure plate or the flywheel in the wrong position? thanks

Ok in that case it should not be a problem.

i did lightly oil the bores before i put the head on.

going to leave it for tonight.

see if it will start in the morning. if not i will have a look at the diagnostics. if not good i will whip the head off and cry any oil/petrol out from the bores and try again. if not it will have to be engine out and looking at the clutch end to make sure things are looking ok there.

can anyone think of/suggest anything else that i can try before its head off and engine out? thanks

Compression test?

i could - is there any point? its a fresh rebore with new piston/rings, and i have freshly lapped the valves in. the head was torqued down correctly. it has only turned over and not fired into life. the head is good as i was using it on my other engine until a couple of days ago

Edited by welshdan on 18th Nov, 2009.

the flywheel should have two dowlels to prevent it being fited to the pressure plate wrong.

it may be possible to mount the middle part that bolts to the pressure plate on wrong, but i'm guessing you havent unbolted this.

It is possible to bolt the flywheel on 180 degrees out despite the offset key way if you are really not paying attention.

didnt touch the centre part of the pressure plate, so this should be ok.

i was tired when putting the flywheel end together, so cant remember exactly what i did. may get the engine back out and have another look at it tomorrow.

Crank sensor works as you say you are getting fuel and a spark.

If the cam sensor is broken or disconnected, it just won start. Like wise if the air temp sensor is disconnected or open circuit it wont start, and much the same for the coolant temp sensor, it doesnt have to be short or open circuit for it o cause major problems.

I urge you to make sure that the plug leads are in the correct order. The cylinder numbers are marked on the triangular suport bits on the main part of the coil body, DO NOT use the rover workshop manual as a reference, its wrong!!

Check where the coil is firing, use the timing light in the normal fashion. first sett up a TDC mark on the pulley and a pointer on the engine. The TDC mark should be no more than 10-15mm before the pointer

Edited by Sprocket on 18th Nov, 2009.

yes, the plugs are sparking, there is the smell of fuel. i looked into the throttle body last night before i packed in and the inside of the inlet manifold was wet.

the spark doesnt seem too bright though (checked on spark tester)

the cam sensor is definately connected. i have also changed this for a known working sensor and reconnected it.

i was wonering how sensitive this sensor is?with regards to the 'injection' lobe on the cam, with the cutout on, does the sensor have to fall just inside the cutout or bang in the middle?

the air temp sensor is connected, it was working on the same car earlier in the week, so cant see this being the problem.

as stated there isnt coolant in the system yet, i will go and fill it with water later incase the sensor doesnt like this. could this be a potential source of the problem?

i marked the plug leads as i tool them off with cable ties, and they stayed connected to the coil pack. this was also working earlier in the week.

the timing light, i marked the timing slit on the crank pulley with a paint pen. using the axis of the marking for tdc on the cam cover, the light was coming on at tdc mark on the pulley (had the timing light set to '0').

today i will recheck sensors. put water in the coolant system. we might try to bump start it by towing. if this doesnt work it will be head off to clean the oil/petrol out of the bores. if that doesnt work we will have to take the engine out and check the flywheel end of things.

unless there is anything we are overlooking?

many thanks


update...

still no joy. have rechecked sensors and they are all in place and connected. the cam, air and water sensors were all used on the previous engine which ran fine. when i take the air sensor out there is an electrical noise briefly when the ignigiton is on (quiet coming from the plug (sugests its working ok)

now got water in the cooling system. no change

also there is a high pitch(but very quiet) noise that seems to be coming from the alternator when the ignition is urned on. i dont know if this is normal? the alternator was also working fine on prev engine.

would it be worth getting a test lamp on all of the wiring to the sensors?

Edited by welshdan on 19th Nov, 2009.

Charge the battery and give it another go.

In the 13's at last!.. Just

just tried to bump start it in the lane. it kind of splutters but doesnt want to start, there is a small amount of fumes coming from the exhaust when this happens.

will try a fresh battery later, i dont think it will make much difference to be honnest.

if that doesnt work will try to get the engine back out tonight to check flywheel and mechanical timings over again. dont think its either of these but really amiss whatto try next.

have tried some diagnostic stuff on it, comes up as 'error',(geniscan obd2) - i am guessing that this isnt mems compatable.

Edited by welshdan on 19th Nov, 2009.

hi chaps. now got this sorted. it seemed down on power trying to turn over, even with a new battery from a deisel. changed the started, still no joy.

was looking at it, next step was to take the engine out and strip it back down.

me and my dad towed it to an industrial estate. put the ignition on, put it in 4th with the clutch down. got up to 30mph, slowly released the cluthc, it popped, spluttered etc, then came to life. dont know if its because all of the bottom end is new so a bit tight?

anyway, it starts and runs now

only problem is the oil pressure. it had all new bottom end bearings, new oil pump (and gasket), but oil pressure showing as 5pounds.

oil light also on at low revs.

the donor block had the oil swith on the front and the other switch there in eachothers places, so think its to do with that switch and ball bearing. will pop back down later and have a look.

other than that, anyone else got any idea on the oil pressure?

cheers

Edited by welshdan on 19th Nov, 2009.

dip the oil an sniff?

sump could have fuel in?