Bongo Fury

Hi everyone, please, please can anyone help. I have had my 2.5 V6 Bongo's timing belt changed and camshaft seals but now she won't start. My local garage said they have checked the timing over and over and that it isn't out, they've changed the spark plugs, new oil and filter but nothing. It turns and it did try to fire twice but then nothing. The compression test come back and they're averaging around 85 to 110.
The mechanic has now said it might be a problem with the o/s lifters because I used a Wynns Lifter Concentrate to quiet them down as they had a slight rattle.

Please if anyone can offer advice it would be very much appreciated. She's LPG converted and drove and started prefect before all of this. She's been off the road for 3 weeks.

Andy.

Sounds like a case of working through logically.

Make sure that the garage has detailed information on the timing marks and setup, they need to refer to the manual not guess from the marks.
Work through the usual ignition faultfinding checks - is there a spark? Is the spark timing correct (e.g. distributor may have moved). Are the plugs connected in the right order on the distributor? Do they have the correct plug type/reach?
Is there fuel getting to the cylinders (sorry not sure if it's injection or carb on the V6), do the plugs get wet?
Are there any sensors which control the ignition - check for fault codes in case a sensor has gone down - perhaps emission sensor?

Allan has replied to the email from your garage.
And he's assumed your mechanic has checked all the usual culprits.

Was this resolved? If so how? I have a what might be a similar problem.
Thanks

Did I read this problem can result from a goosed crankshaft sensor?