PD Cold Starting Issues

First I hope I've posted this in the right section, although my query is slightly non standard it is entirely about the PD engine
I have a Mk1 Caddy with a ASZ PD Engine, which I installed myself




It has been great driving round with the increased torque and power (a bit of a step up from the 54HP!)

However I have an issue: On start up the car seems to misfire? There is a lot of white smoke and it sounds to me like one cylinder is missing, but I'm afraid I don't really know all that much about these engines to say. After the engine warms up a bit the misfire goes away, which is why I've lived with it for a couple of thousand miles, but now I really want to sort it.

I hooked the car up to VAGCOM and got these readings out of the Measuring Blocks at cold start:



A few minutes later the values even out and the engine runs much more smoothly without the smoke:



Could this be some sort of lazy injector issue? Is one injector injecting too much or not at all do you guys think?

Ideally I'd not like to pay to have all the injectors rebuilt, but I guess I may have to go down that route if it comes to it.

Thanks in advance for any pointers,

Rufus

That is a nice looking engine bay. I’m not at all familiar with the ASZ but the only real problem with the BEW or BRM PD engines is potential cam wear. Have you checked to see if the lobes all have chamfers? Do a search for cam wear and you will find pictures and descriptions of what I mean.

O-rings on injectors could be shot allowing air into the system.

I'll pop the rocker cover this evening or tomorrow and take a gander! If the O-rings are shot is there any way of diagnosing this? Would you suggest the seals are shot on cylinder 3 or 4 or both?

So I popped it and the cams look pretty fine to me, this was the worst of it. Tomorrow I'll properly inspect by checking the chamfered edges all the way round. For now I think this points me even further towards injector seals / or a leaking injector. Does anyone on here have experience with the symptoms of dead seals or a leaking injector?

I've read here that the electrical wiring harness to one or more injectors could deteriorate over time due to heat.

JB05 said:

I've read here that the electrical wiring harness to one or more injectors could deteriorate over time due to heat.

Click to expand...

I've also read that, however I was pushed away from that diagnosis by it running much better with a little bit of heat in it?


I'm going to compression test next

No real way of knowing that the orings are sealing correctly, the cold start symptoms are the same as I had. I replaced them along with the clamp bolts and car is starting perfectly now.

Just trying to avoid the cost of replacing all the seals really.... Maybe it'll go that way.


Did your car show any other symptoms like air in fuel?

Would startup with a misfire on the engine and whiteish smoke from exhaust. After about 10 seconds the misfire would go away. I replaced the injector seals on all 4 injectors with ones from FAI. The bolts were genuine VW. When the injectors were out, I also tightened up the female recepicals in the injector loom plugs for the 4 injectors. Car hasnt looked behind it since all this was done. Parts cost less than £50.

Cheers for the pointer Arnie

Should I be worried about oil leaking out of here? Slowly but surely