Anyone know how to check the injection timing on an 1990 N12 a td122 in it (intercooled)? It over revved, backfired and died in a cloud of white smoke.
I’ve triple checked for air, intake and exhauSt blockages and all it does is crank with clouds of white smoke but not even a hint of a fire. It’s getting fuel to injectors, and heaps to the pump. The pump drive shaft appears good, to tight and no sign of slippage. It will fire with aerostart. Starting to get desperate I want to check the injection timing - assuming it’s go timing gears so don’t know how it could be out but not sure where else to look right now...
Over revved, how much over rev and for how long? White smoke says timing off, bad injector/s, bad compression or poor fuel supply
Possible valve damage from the over rev. What caused the over rev?
Blackduck59 wrote: Over revved, how much over rev and for how long? White smoke says timing off, bad injector/s, bad compression or poor fuel supply Possible valve damage from the over rev. What caused the over rev?
I'm with Steve. Pull the Rocker cover Off & check for bent pushrods & valves..
Just my 2 cents worth..
"Be who you are and say what you feel...
Because those that matter...
And those that mind....
don't matter." -
Thanks guys. Ended up finding it should be timed at 19* BTDC. Pump drive had slipped on the timing gear shaft and had become 20* ATDC. Apparently not uncommon for these TD122Fs - the earlier N12s had a Keyed shaft but they used to break to break the key... Reset it and runs good as ever.
Why it over revved is a different issue... has an IP issue where when it reaches full operating temp and when pushed fairly hard it develops some rather nasty habits - mostly reduced power and it keeps pulling for about 5seconds even not touching the throttle. If at this stage you hit the clutch the revs go through the roof. It’s an occasional use farm truck and the manager hadn’t wanted to fork out for pump work, but I think he might finally be rethinking this...
Not up to speed on those, looks like a P pump with 12mm plungers. Think the early versions had their own lube later ones were hooked up to the engine oil supply. If there is an oil line coming from the block then it is engine lubed, if not may need to check the oil levels in the pump and governor.
Sounds a bit like the governor is hanging and with the reference to doing this when hot sort of suggests lack of lube.
Spent the whole day trying to sort out a Bosch VE on my Cummins, finally figured a spring in the governor assembly may have disappeared, at least I finally got it running now just need to up the fuel to it.
It may be one of the later engines which had an "injection timing adjuster" which fits in line with the pump drive line. The function of this device is to advance and retard the injection timing similar to a distributor in a spark ignition motor. Has springs'n stuff inside it so that could be your problem. As in a distributor static timing is your starting point.