V6 wont start after cam belt change

[mikeWalsall]

If the piston is coming up to TDC .. the timing marks line up .. the rotor is pointing to number one terminal in the dizzy cap .. there is fuel and a spark .. it should fire up ..

[helen&tony]

Hi
Simon..
Do you have a manual to see if it's a worm drive...?...That was the same with the VW, except different cam arrangement, but the drive had the offset key at the dizzy end...if the drive is like that, and the worm is a bit slack, it can be pulled out a bit when removing the dizzy, and push back in again, and there is a precise sequence for getting it in again, because they tun about 1 1/4 or 1 1/2 turns when they go in (on the VW), so if you start 1 tooth or more out, you may end up with all the marks lining up, but no chance of running.
As I say, I'm guessing, and it might not be true at all, and certainly the Volvo I had ran fine, but it sure wasn't running RIGHT...used fuel like a demon, and only possible to time by ear...how the *** ran at all, I don't know...I nearly threw away a very expensive timing light, and a couple of others, until I tried them on another vehicle!
Cheers
Helen

[jimmo62]

Good point about the timing light, that would be worth trying as it would confirm for sure that the distributor was in the right place and the spark was happening at the right time.....

[foxuke]

Thanks for this.
However, I don't quite understand, given everything Mark has done, listed above, how the timing can still be out? How is what you are suggesting with the worm drive thingy going to show up differently.
A.

[helen&tony]

Hi
Please note that I'm only postulating...I don't know the engine at all, so someone with a manual may see whether there is a driven drive shaft under the dizzy?....The shaft MAY have a worm drive if it is driven, and as such is a "spiral", and can be put in wrongly , and as it goes in, the drive shaft will turn as it engages. When removing the dizzy, it may just grab the back of the dizzy enough to pull forward, then when the dizzy is put back in, the rotor arm drive will turn, such that when out put the rotor back in, it can happen that it will line up with the timing marks...but the beggar won't run properly!...
Just wondering regarding the above , because the mechanic seems to have covered most avenues. The only other thing it could be is IF the rotor arm is new, they can be faulty. I always renew all the electrics when I have a new vehicle, and I did this on one car, and the beggar wouldn't start....Spent hours doing it and re-doing it, until I remembered that a friend once had a faulty one. I replaced it with the old one and it started at a touch!
How the rotor very occasionally fails is this:...during manufacturing, there is a bubble of air caught in the moulding process, which causes a spark to jump into the bubble, and then to the rotor shaft, as there is insufficient insulation for the very high voltage. It's a one in a million chance, but I've known it twice!!!
Cheers
Helen

[mikeWalsall]

Carbon pick up still in the middle of the dizzy cap ..??

[windywatson]

Hi, with respect to the hydrolic valve lifters, my V6 camper is only used during the camping season. So it can sometimes stand for a few months over the winter period with only the occasional start. I have no problem with the valve lifters draining back! I would expect that if the engine turns over fast enough on starting that the oil pressure will lift the valves extreamly quickly. I have seen oil pressure reach good enough pressure to turn oil pressure lights out whilst being turned over on starter motor only.
Also, even with low compressions I would expect the engine to still fire up and run even if uneven. Is it possible that during the work something has been disturbed & effected the fuel pump?

cheers

[foxuke]

Thanks Windy
Fuel is working fine.
A

[Simon Jones]

Hi
Simon..
Do you have a manual to see if it's a worm drive...?...

I've got the engine manual but it's in the van which is locked away in the the bat cave until the weekend at the earliest .

[helen&tony]

Hi Simon...
Weekend it is , then...but is there a Lushprojects for the V6 & 2 litre?...If not, is there any chance of getting similar from the Mazda main dealer to assist us in ordering?...a printout of the parts catalogue if begged on bended knee?
Cheers
Helen

[mikeWalsall]

All the Bongos up to around 2001 are on the Lush Parts lists ..

http://lushprojects.com/bongopartsmk2/

[kingrollo]

Any updates on this ?

[foxuke]

Still not sorted. So keep thinking please.
Its getting a fresh pair of eyes this afternoon so hoping for an update tomorrow.
Thanks for asking.

[jimmo62]

Did you try dynamic timing with a strobe light - that would confirm both timing and spark are OK?

[Simon Jones]

I went to see the van today and had a long chat with the mechanic. He is clearly very knowledgable and has a lot of experience with Bongos and many other Japanese imports. He has performed a very though fault-finding process and by rights the thing should be running now but there is still one piece of the jigsaw that has yet to be found.

I've messaged a few observations to Andy and if he's happy for me to update this thread, then I'll report back presently.