V6 Petrol AFT - Weird Startup Problem

[LesCarter]

Hello, I'd like your thoughts on this please, any help very much appreciated.

I have been getting an intermittent starting problem. Engine sometimes turns over but doesn't fire up. When it does this no amount of persuading can get it going. The AA man drew a blank with it.

I had a local mechanic look at it yesterday, he pulled connections and re-connected, he cleaned up some corroded contacts. Then miraculously, it started up perfectly and did so for the rest of the day. He said he had no idea what fixed it and it could go wrong again.

This morning, I am back with the same problem, it won't start, not even a splutter.

When it does start, the engine doesn't miss a beat and starts in a split second of turning the key.

Has anyone else come across this before? I think the problem turns up more in damp conditions.

Les

[Bongolia]

Well it could be anything frankly.
The damp conditions may be a clue to ignition related problem or it may be a red herring.
When the mechanics looked at the vehicle was it presenting the problem? Did they check for fault codes?

When this happens you need to start by checking the basics first that is are you getting fuel and are you getting ignition.
The ignition one is the easiest to do. Use a known good spark plug. When you have the problem pull off an ignition lead and plug in the spark plug rest it against the engine block and crank the engine. Dont be tempted to hold the ignition lead against the block as this can damage the ignition module and also give a nasty and potentially dangerous shock.
Got a spark? If yes now move on to the fuel remove a spark plug is it wet and if it is is it fuel?

[g8dhe]

Go thru every fuse (other than the 100 Amp on the battery) pull it and clean the contacts, it could be something like the fuel pump fuse, without power to the pump you won't be going anywhere!

[LesCarter]

Thanks for both of your replies, I will go though all of the fuses (apart from the main one). I have the fuse diagrams downloaded from here. There doesn't seem to be one specific for the fuel pump, is that one separate?

When the AA man was checking things, he checked for a spark and there was one, although he said it might be a bit weak. He also disconnected one of the fuel pipes near the engine and there was definitely fuel getting to that bit.

[LesCarter]

Ok, I have done the fuse thing to no avail. Also wiggled a lot of contacts / wires in hope, but so far nothing.

[cmm303]

This thread is worth a read, just ignore the LPG wanderings if not relevant.
http://igmaynard.co.uk/bongo/forum/view ... t&start=15

Dizzy cap and HT leads are prime suspects for damp related problems
The crankshaft sensor is susceptible to puddle spray when driving, but not ruling anything out. Dodgy connection perhaps?

[New Forest Terrier]

Had this with my V6. The carbon finger on the distributor was worn leading to a larger spark gap, that resulted in the spark not being strong enough in damp conditions. Replacing this plus new plugs cured it completely.

[New Forest Terrier]

Had this with my V6. The carbon finger on the distributor was worn leading to a larger spark gap, that resulted in the spark not being strong enough in damp conditions. Replacing this plus new plugs cured it completely.

[LesCarter]

Should have said before, but it has a brand new Mazda distributor, from Japan, which cost me £600!

Have tried WD40 on the crankshaft sensor as this has solved the problem once before when it was very damp and wouldn't start. I also have had that puddle problem, once on a very busy A1!

I am now getting a bit panicky as i have to be at Glastonbury festival by end of play tomorrow. I'm playing 2 gigs there.

[Bongolia]

OK. So why was the distributor replaced in the first instance?
Has anyone code read the ECU?
Have you the old distributor still?

[Bongolia]

What is the engine code and what is the registration you could PM it me if you dont want to post here.
Additionally were the leads changed when the new dissy was fitted?

[Bongolia]

I keep pushing bl**dy submit key. Sorry.
The other part of the equation is air.
You should check all vacuum hoses/air hoses and the air flow meter mechanically to ensure it is opening freely.
In addition there is a valve on the top of the engine referred to as an air idle screw.
http://lushprojects.com/bongopartsmk2/c ... o=.html#18
the part is 23-6823 make sure that is clean and not blocked.
Keep us posted.

[LesCarter]

Hi Bongolia, I have PM'd you my engine info.

I will see if I can get to the air idle screw, although if it is on driver-side it's pretty hard to get to due to my conversion.

Les

[LesCarter]

Distributor was replaced due to the Bongo stopping when in traffic, the diagnostic pointed to a bistro sensor problem.

After if was fixed, I found out that the breather in the petrol tank was blocked and it was sucking in the petrol tank like a squashed coke can.

My mate took off the petrol tank and blew it back out, straightening the fuel pick-up and float.

As I have said before though, once the van starts, it runs perfectly.

Les

[wonkanoby]

try loosening petrol cap