Ok. here we go.

1997 4.0ltr gems on petrol/lpg.

Bought running. no problems starting or running etc etc on lpg or petrol. However, down on power alot and not very smooth.
Ripped it down the centre and found duff cam lobs so off it all comes.
Replaced:
CAM
LIFTERS
CAM CHAIN/SPROCKETS
HEAD GASKETS
LAPPED IN VALVES INC STEM SEALS
ALL USUAL GASKETS TO DO WITH ABOVE

AFTER RE-BUILT, STARTED AND AFTER INITIAL BAG OF NAILS 2 MINUTES SETTLED DOWN AND PURRED LIKE A KITTEN

(Ooops, caps on) So, really chuffed obviously. Very smooth acceleration. Turned it off, checked coolant/oil etc etc, had a cup of coffee, went to restart and it coughed and spluttered and would not catch. tried again and started after a couple of coughs and ran perfect, then, stall, as in crank sensor type, not lack of fuel stumbling stall. Would not start even with pedal down.(although felt like it was trying to fire as if there was no fuel(yes there is!))
Left it for a while while I pondered.
Tried it again, it caught and held revs at 2500. then it started to turn off and on, as if you were turning it off and on. Would rev to 2.5k. hold for a second then die then rev again, all the while i have my foot on throttle.
Left it for a while to cool down.
Tried from cold, didnt want to start, really high fuel content from exhaust(smell). Then caught and ran perfectly until warmish(60 degrees ish) then it starts to hunt a little, then alot, then stalls. Then wont restart and bad fuel smell like flooding when trying to restart.
If you turn it over without throttle, it fires, revs to 1500 then dies unless you give it throttle and it may make a difference and cough and spultter and may catch and run. A bit hit amd miss and very tempramental.
When its running, its runs perfect and its very sweet and smooth. I have a generic obd reader and everything seems normal. However, just now i waited unitl it warmed up from cold while I watched the live data. Then it started to hunt around 60c and the maf reading went bonkers and the fuel smell was bad then it died and wouldn't restart. Changed the maf and no difference.
So, to summarize,

It might start or not, hot or cold, seems worse when hot. when left idling it will either eventually hunt/flood then die or just switch off instantly.

I've checked: coolant temp sensor, reluctor ring and ckp(although not changed), tps (showing 11.8-80%), iacv,

Just to point out, its not anything to do with fuel pressure etc as it will do exactly the same on LPG. Its as if incorrect or missing info being given to engine ecu and it either floods or just literally turns off.

This ones got me. what do you reckon, anyone fancy a stab at this one? there are a couple of you on here I would love to hear your opinion.

Cheers

 

Bent tabs on reluctor disk that drive sthe crank position sensor?