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LH2.4 only 2 sparks on crank, but once started runs perfect?

105Charlie

New member
Joined
Jan 21, 2018
As title, Volvo 343 converted to LH2.4 and 200ft from a 940.

Had been starting fine for weeks but now will only spark twice on crank start and then usually once more when I come off the key. Started testing but can't find anything reading wrong and it's strange as if I manage to get it to start via a key/accelerator dance it runs absolutely fine.

Ideas?!
 
Check the values for the coil and the power stage would be where I'd start.

There may be something odd happening with power coming off of battery to those items and for some reason only supports enough energy for 2 sparks but would otherwise run fine on alternator power?
 
Ignition switch problem. The switch uses two different contacts to supply power to the ignition system depending whether the key is in the start position or run position. It sounds like the start position contact is worn out.
 
I checked everything with a multimeter and it seems to read right (everything is a little off but should be negligible)

Ignition switch problem. The switch uses two different contacts to supply power to the ignition system depending whether the key is in the start position or run position. It sounds like the start position contact is worn out.

That's interesting, I never thought of that! I will check that out and try hot-wiring it and see if it works as expected
 
Just leave the key in the run position, engine off, and trigger the starter with a remote starter switch or screwdriver, whatever you have on hand. If it fires right up every time, 99% chance it is the switch that is causing problems.
 
Also there are some pins in the lh2.4 ECU that need power while cranking. Maybe in your making your 343 2.4 you didn't wire it correctly or like 2manytubos says your ignition switch cuts power to what needs power while cranking. On a 240 you can take it apart and move the wire pins to what you want. No clue about 343's as they never sold them anywhere round here, this here is bricktown.

http://forums.turbobricks.com/showthread.php?t=230687



Wire 3: Blue: Ignition ON signal.


1- blue wire, this supplies switched 12v. without this, you will get no spark, and no fuel pumps. it connects to pin 35 on the ECU, pin 4 of the diagnostic connection, pin 6 of the EZK, and one of the pins in the CA EGR cars. ultimately you want it hooked to pin 15 of the ignition switch. NOTE: you must use an lh2.4 ignition switch for this pinout to be accurate, also, make sure you are referencing the pin numbers on the switch, not on the connector.

Like I said on the earlier kjet 240 cars you can take the ignition switch wire plug behind it apart and repin it so it will then work with lh2.4. Who knows what you can do with a 343...
 
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