spark plugs dysfunction

zere · Post by **zere** » 23 Dec 2017, 07:25

850 volvo 1995 sedan no spark plugs function after overhaul

zere · Post by **zere** » 23 Dec 2017, 07:30

After over haul of engine the spark plugs are not functioning though the engine cranks

Post by **scot850** » 23 Dec 2017, 07:44

Can you give more details of what you mean by 'overhaul'? Did you service the car, and if so what did you replace? What brand of parts did you use during the servicing as these cars can be quirky with what works in them.

Neil.

Post by **tryingbe** » 23 Dec 2017, 12:03

Crank sensor installed?
Rotor inside the cap installed?

Post by **jimmy57** » 23 Dec 2017, 12:17

If the cam sensor reluctor on back of intake cam is not properly fitted or left off then the ignition control unit or ECM (1995 could be EZK129 with LH 3.2 fuel injection, Bosch Motronic 4.3, or Siemens. I am unsure what is used on that car in Africa) then the synchronization of crank and cam can't be done to allow it to figure the firing order. TDC falls in one sequence for one revolution relative to crank reference marking and is 72 degrees later for the last two cylinders. As a result it will not spark if the crank cam sync is not possible to avoid a possible backfire if it fires 72 degrees off.