Brain storming
Turbo Mini Forums

I have a problem I would like some brain storming on. I have my own thoughts but looking to see if there are any I have overlooked.

The hardware

1380cc engine
BMW K1200 head
Wasted spark ignition 1-4 and 2-3
Injectors paired 1-4 and 2-3
Laminated steel head gasket
Dry deck

The problem

Engine first started and only ever ran on two cylinders 3 and 4. There are sparks on all four cylinders checked with strobe. There is fuel in the cylinders. The cylinders are not flooded, the plugs are dray and clean, plug gaps are correct. Compression test was not done, yet, as the gauge had gon missing, it was late and i wasnt going home to come back with mine .

What do you recon it could be

In theory, if you have a spark on 3 or 4 you have a spark on 1 or 2. If you have fuel on 3 or 4 you have fuel on 1 or 2. So we have fuel, (deffo as when you remove the plug vapours rise from the cylinder) and a spark ( strobe checked) why is there no bang?

timing?

as above....ignition timing

edit...or cam timing

Edited by Jason G on 14th Sep, 2008.

wrong plugs? i know peugeots run crap on NGK but really well on bosh.
and as above timing? could be leads, or poor connection on the plugs as well. could be really odvious

Drives
-Ford S-max Mk2 Ecoboost
-Rover 100 VVC #2 - track project

Searching is all you need on TurboMinis

Forgot to add that the maps and start parameters are suposedly of and identical engine that has been mapped and running

The ECU is a DTA which has an osciloscope to aproximately determine the crank sensor position, this value was used, and checked with the strobe while cranking over with a 10 degree starting advance, and confirmed to be pretty dam close to get things running.

If anything the fueling should be slightly richer as the FPR used is refferenced to atmosphere and 3.5bar at atmospheric.

These are NGK plugs and are the same ones in several other similar engines.

Little more info. I know that cylinder 1 and 2 are deffo not firing as the exhaust manifold on those cylinders is stone cold while 3 4 are burn your fingers hot. Its not even trying to fire 1-2

Edited by Sprocket on 14th Sep, 2008.

do you know that there is definately feul getting into 1 and 2?

its abit dangerous but could you whip the feul rail and injectors off and see if they are all firing correctly?

erm doesent the k head on the a series block end up with a different firing order?

meaning you need to pair the wasted spark 1,2 3,4

duff coil,???

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

I would look at the coil.

Even if the strobe has picked up the spark, the volts may not be enough if there is a fault.

Would it run on 1&2 if you swap the leads around 1 to 4 and 2 to 3?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Firing order is 1243. Normal firing order is 1342, so as you can see on wasted spark, and batch fire, it wont make any difference about the different firing order

Yes, things to check, swap injectors round, a swap plugs around, swap leads around, and change out coil pack for a known good one. All one at a time

And yes there is deffo fuel there :)

Coil pack is a brand new item, but its not a genuine Sagem item (same as the MPi and Vauxhall items) The coil resistance is 0.7 ohms per coil and that checks out with the coils in series as 1.4 ohms.

Keep it coming chaps, this is all stuff i have gone over in my head :) and until we do a compression test, im still thinking its a head gasket issue

is this with tb's or a plenum?

if the latter could stuff a blow torch up the inlet and see if it runs on 4 on gas,

helped me isolate my fuel issue!

TB's

Its the same with revs increased

have you checked compressions, could valves not ne seating fully, have you shimmed up correctly,?

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

Hi,
What he said ^
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

WB/EGT gauges. Click here for customers write-up

Visit www.doyouneedabrain.co.uk

My Mini build diary

Not my engine, but its one thing on the list to check :)

I think I'm probably saying the same as Paul but for a different reason but try swapping the leads 1 to 4 and 2 to 3.

On the surface it should make absolutely no difference as the coilpack fires 1 and 4 together (and 2 and 3 together) but because there are only two coils in a coilpack and the HT goes from one end of the coil through one plug, then the block, then the other plug then back to the other end of the coil, two of the plugs have the opposite polarity to the other two. Some plugs are sensitive to this.

Schrödinger's cat - so which one am I ???

That was my thinking Rod.

Have you also considered that the ECU may not be reading he crank sensor correctly, or the ECU thinks it a two cylinder engine?

It could be that the plugs are only firing every 720 degrees, rather than 360. That would explain the problem.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Stuff a Dizzy in it lol

(i'm asuming this is an MPI block)

Isn't this the same sort of problem that Joe had?

He ended up re-flashing the ECU on Paul's advice (after hours of messing about with everything else).

P.s I thought Brainstorming is no longer a pc term as it's also used to describe a type of epileptic fit?

In the 13's at last!.. Just

When was the last time TM was PC.

Its the first I heard about 'brain storming' being PC. I have never heard anything so daft

On 15th Sep, 2008 Sprocket said:
When was the last time TM was PC.

Its the first I heard about 'brain storming' being PC. I have never heard anything so daft

In the 13's at last!.. Just

This is a typical Example of valve seat not sealing, Do a Compression test all will be reviled

crank has snapped, only 2 pistons are moving.

you forgot to fit the pistons and or valves for cyl 1&2

you left rags stuffed in the inlet of 1&2 durign the engien build phase. ( my brother has done this, but with paper towels, got nice carbon confetti ou the exhaust on first start )

but in all seriousness, my moneys on the ecu thinking its a 2 cylinder engine :)

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.