M43 to M44 using M43 wiring harness.

Daspete

Daspete

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Jan 13, 2019
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So those of you who are contemplating swapping out that horrid M43 but the thought of new looms etc puts you off. I've fitted a 1997 engine to a late 2001 car with only simple modifications with no special tools etc.

I will post up later on with what i did. At the moment it's a very rough basic install to see if it works.
Transferring all the emmisions stuff will be a bit of a faf but looks easy enough.
 
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You need the M44 engine,
Coil pack with leads,
Manifolds,
Exhaust,
Clutch and flywheel,
Cover plate between box and bloc,
Rubber intake pipe.

Now from your M43 you will need
Starter,
Alternator,
Air flow meter,
All the sensors as you will need to swap them as they have different connectors.
Ping sensors,

2 wires need extending and the cam position sensor needs modification.
You can't use the hall effect sensor that comes on the M44 but the one from the M43 is too long. What you need to do is pack out the sensor i think 7.5mm. I have it written downsomewhere. It took alot of working out. For the test it was a bit of pipe but I'm having a proper adapter made now it works just for neatness.

You will also need to weld another lambda sensor boss on the exhaust too as later models have 2.

The only outstanding connection is the one that went to the thermostat on the M43.

I haven't connected the secondary air injection yet either as that will require parts from the US.

So far it runs but not perfect.
 
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After more work I've since discovered you don't need the radiator pipe work. You just need to cut the metal band off holding the connector on so you can connect the pipes using jubilee clips instead. If you have a dremmel use that or a grinder surgically lol
 
So after much fettling I've hit a wall. Everything now works apart from the cam position sensor. Tried everything and i still get a signal error even with a new sensor . It starts and runs but can be lumpy and seems sluggish to respond.

Unless i can find an engine management guru that can tell me why it doesn't work, it looks like i may have to admit defeat and put the M43 back in. Dam and blast.
 
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Daspete said:
How do i find that out?
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Actually scratch that ide you will using the m43 dme ( as you are using the m43 wiring loom so you must still have the m43 dme)

As far as your cam sensor the next thing I'd maybe look at is what the sensor pick up from on cam
20180413_203529.webp
this is the sensor pick up plate on an m44 I would maybe pull the rocker cover off the m43 unit and compare it
 
Nodzed said:
@Lee ??
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Don't know with the 4cyl engines the harnesses are different for the 6cyl. I would have thought the 43 & 44 would differ. They are plug n play so I would just find the correct harness.
 
Stevo7682 said:
Actually scratch that ide you will using the m43 dme ( as you are using the m43 wiring loom so you must still have the m43 dme)

As far as your cam sensor the next thing I'd maybe look at is what the sensor pick up from on cam View attachment 125021this is the sensor pick up plate on an m44 I would maybe pull the rocker cover off the m43 unit and compare it
Click to expand...

That was one of the first things i looked at. I swapped them over as they are totally different but the engine just back fired loads and barely ran. Made sure the arrow was in the correct position too.
The M43s wheel is much simpler, the tab is solid for 180 degrees and none for the other 180.
 
From my personal thoughts I think the biggest problem could still be waiting in the wings and that is whether the m44 will ever run clean enough to keep all the sensors happy I have both
The m43 always sails through emission test
M44 always struggles even after an engine rebuild and new cat
 
Stevo7682 said:
From my personal thoughts I think the biggest problem could still be waiting in the wings and that is whether the m44 will ever run clean enough to keep all the sensors happy I have both
The m43 always sails through emission test
M44 always struggles even after an engine rebuild and new cat
Click to expand...
That is a concern, i have modified the exhaust for the extra oxygen sensor which made it run better but yes, bit worried about the MOT.
 
Have you moved over to the newer M44 ecu ? I see your also using the old M43 MAF have you tried running it without the MAF plugged in.
 
Lee said:
Have you moved over to the newer M44 ecu ? I see your also using the old M43 MAF have you tried running it without the MAF plugged in.
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No using a late model M43 ECU and loom.
Never thought of running it without the MAF. Any reason for that?
Getting a P0340 fault code.
 
Running with the MAF disconnected makes it run default mode.

Tony.
 
Daspete said:
No using a late model M43 ECU and loom.
Never thought of running it without the MAF. Any reason for that?
Getting a P0340 fault code.
Click to expand...

Would it be easier to grab an M44 loom, they are literally plug n play, the connectors can only go in one place. Unless they are the same looms between the two.

Unplugging the MAF is a good way to diagnose if its working or not. The engine runs a default map when it cant detect a maf plugged in.

Yeah that code is a Camshaft sensor for sure.
 
Might be worth checking the crankshaft sensor too.

Tony.
 
t-tony said:
Might be worth checking the crankshaft sensor too.

Tony.
Click to expand...

That's brand new decent quality one and it is giving the right numers on a volt meter. With the ghetto test using a spanner in front of it, it triggers the injectors which baffles me.
 
Lee said:
Would it be easier to grab an M44 loom, they are literally plug n play, the connectors can only go in one place. Unless they are the same looms between the two.

Unplugging the MAF is a good way to diagnose if its working or not. The engine runs a default map when it cant detect a maf plugged in.

Yeah that code is a Camshaft sensor for sure.
Click to expand...

I assume that would be changing the ECU as well?
I have the engine part of the loom that i took off to thread the M43s in instead. The loom is all one piece on my car which is irritating.
 
Here's another thought is it possible the cam wheel pick up point is at a different timing point and the dme thinks the timing is out :bookworm::bookworm: as both cars crank sensor should pick up tdc but if the cam pick up point is a number of degrees different could throw up the fault ( have had the m44 apart but not the m43:thumbsup: as funnily enough it's been the more reliable and economic of the 2 of mine :rolleyes::rolleyes:) so it's just a thought as at the end of the day if your stuck :banghead: any idea is potentially a good one :angelic::angelic:( or not :ymdevil: )
Stephen :).
 
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