Hi all
the brother in-law's laguna 1600cc 16v on a X plate year 2000 .
no.4 coil died, make is denso not the sagem type, so replaced it (from renault) and car still ran on 2 cylinders ( 2&3 )
All plugs replaced with new multi point type (from renault) still ran on 2&3 , moved coils + plugs from 1&4 into 2&3 position and 2&3 coils + plugs to 1&4. IT still runs on cylinders 2&3, checked all possible visabile fuses (visual inspection by removal only - meter at work!!) inc the big ones in engine compartment.
phoned renault and asked a techie if this was a known fault, they assured me it wasn't ( i suspect ecu failure on 1&4 output ) @£500 odd quid for a new one, they aren't gonna let me have one sale or return LOL!
I am assuming theres only one crank sensor and the ecu controls All 4 outputs to coil packs. unless there's 2 and the coils fire in pairs like some fords do?
Also theres a strong smell of petrol in engine bay , I am hoping it's because of 2 cylinders not fireing and not because of any other fault.
anybody any ideas on this before i go back and investigate some more.
regards gary
2000 Laguna 1.6 16v Coil/spark problem + excess fuel
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ukmobileman
- Posts: 113
- Joined: 22 Dec 2001, 21:52
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AndersDK
- Posts: 6060
- Joined: 21 Feb 2003, 04:56
- x 1
I'm only guessing out of knowledge from common design principles.
Firstly I'd assume that 2 cylinders are fired simoultaneosly (1 on compression 1 on exhaust stroke).
Next I assume the coil packs are the later mini types directly fitted as single units on top of the spark plugs.
Consequently there are only 2 breaker signals from the ECU driving each pair of coils. The ECU in turn gets its signal from a single crank position sensor by a notch in the flywheel at 0 & 180 degree.
Next thing from my knowledge bank is, that recent car electronics is VERY reliable and does not pack up just like this. It is MUCH more likely to have a cable/connector problem. Especially on french cars !
I'd therefore try trace backwards from the dead coil packs, looking for a missing earth connection in the wiring to the dead coils. This is done using fairly easy lo-tech car electrics faultfinding techniques, mated with your logic sense
Firstly I'd assume that 2 cylinders are fired simoultaneosly (1 on compression 1 on exhaust stroke).
Next I assume the coil packs are the later mini types directly fitted as single units on top of the spark plugs.
Consequently there are only 2 breaker signals from the ECU driving each pair of coils. The ECU in turn gets its signal from a single crank position sensor by a notch in the flywheel at 0 & 180 degree.
Next thing from my knowledge bank is, that recent car electronics is VERY reliable and does not pack up just like this. It is MUCH more likely to have a cable/connector problem. Especially on french cars !
I'd therefore try trace backwards from the dead coil packs, looking for a missing earth connection in the wiring to the dead coils. This is done using fairly easy lo-tech car electrics faultfinding techniques, mated with your logic sense
Anders (DK) - '90 BX16Image
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ukmobileman
- Posts: 113
- Joined: 22 Dec 2001, 21:52
update
update on laguna
checked all 4 coils packs + wiring for breaks , resistance and continuity, all OK and working ok
with car running (on 2cyls) cylinders 2+3 coils fire correctly - that being the coil is enigized with 12v, the earth (or signal) wire has it circuit broken by ecu/tdc sensor, the coil fires as it should be!
But 1+4 coils have 12v showing and the earth (signal wire) never gets the circuit broken to fire coils. If i turn ignition off and on quickly coils 1+ 4 fire!
surely this must be a ecu fault rather than a tdc sensor ?
checked all 4 coils packs + wiring for breaks , resistance and continuity, all OK and working ok
with car running (on 2cyls) cylinders 2+3 coils fire correctly - that being the coil is enigized with 12v, the earth (or signal) wire has it circuit broken by ecu/tdc sensor, the coil fires as it should be!
But 1+4 coils have 12v showing and the earth (signal wire) never gets the circuit broken to fire coils. If i turn ignition off and on quickly coils 1+ 4 fire!
surely this must be a ecu fault rather than a tdc sensor ?