Misfire again

[GeoffSmith]

When loosing power comes in a pair,
There is something to be aware:
If the loss is even or odd,
Loss of fuel may be the sod.
If the sum adds up to five,
Sparky bits may not be live.

In other words, the fuel injectors are paired 1&3 and 2&4 whereas coil packs are paired 1&4 and 2&3. If you've lost 1&4 Martin, it would be worth swapping the coil packs over to see if it shifts.

[Sy V]

Fever clucker!

[GeoffSmith]

[Martin R]

Geoff, thanks for that. I have tried the plugs out of the engine and there appears to be a healthy spark. I will swop the injecors around and see if the problem moves. If not i will swop the coil packs next. Is everything hard to access on a Elan though As in being retrained next week full time it will be the weekend before i can get to it.

[Martin R]

A quick update on this as i have had another fun morning on the Elan. Ive swopped the injectors around and it made no difference. The misfire was still on 1 & 4. I then swopped the coil packs around. After a lot of swearing i managed it. The misfire moved to 2 & 3. The coil pack for 1 & 4 would appear to be shot. Strange as with the plugs out the car they both appeared to have a healthy spark. It looks like a new coil pack should sort the problem

Edit, thanks to all who have helped on this.

[Martin R]

Swopping the coil pack for 1 & 4 has finally sorted out the problem. I would like to thank all who have helped with this.
Just for reference the secondary resistance on a coil pack should be approx 5.6K Ohms. I would have tested the primary but i couldnt get a reading due to the small size of the access to the connections. The secondary is the 2 connections the plug leads go on obviously

Edit.

I managed to squeeze a couple of small crimps in the primary side to get a reading.

Primary approx 0.5 Ohms
Secondary approx 5.5 K Ohms.

That suggests to me the primary takes approx 24 Amps, blimey.

[GeoffSmith]

Sounds about right Martin. The current is initially limited by the inductance (few milliHenry) and the current rises linearly (approximately) towards ~10A in a few milliseconds.

[Sy V]

What he said...

Glad you're sorted Martin.