How to test a suspect delco pcm?

[VTXU8]

Or the maf taken a shit or hose split

Thats a good question! I was making an enclosure for my pod filter as they have to be enclosed to pass for rego. When i removed piping that comes off the maf i noticed that the meshing on the maf was damaged. I removed mesh as i was worried about bits of metal getting sucked into motor. Before i noticed damage to mesh the was missing and running like a dog. That was the first time it started playing up. I removed mesh and tested car and it was running good but soon after it started missing again on cold starts. It would come good or better once it warmed up. But it was never the same after mucking around with pod filter enclosure (i have since removed enclosure after rego inspection). Would a faulty maf cause a no start? I will fit my old maf in and see what happens

[VTXU8]

UPDATE:
I swapped new maf with old working one and no go. I replaced Distributor yesterday and no go. It can only be the PCM. I have replaced and tested everything. Would a BCM cause a no start too? How can I test bcm?

[delcowizzid]

Did you replace the sparkplugs if they are allready soaked and black it won't matter what you change it won't run

[VTXU8]

Did you replace the sparkplugs if they are allready soaked and black it won't matter what you change it won't run

Yes.Plugs are basically new.Done less than 1000ks but i have had faulty new plugs years ago on a non injected car. So before i do anything with pcm, i will buy new plugs and fit tomorrow. If it is the plugs then i'm a D'head for not suspecting them earlier. They do seem to spark well but maybe not enough.

[Gampy]

Just because they spark well in atmospheric pressure doesn't mean they are not failing under cylinder pressure!

So don't beat yourself up too much if that turns out to be the issue.

-Enjoy

[VTXU8]

Well F@#k me! It starts and runs now. Delcowiz, Charlescrown and Gampy were right (sorry if i missed anyone else). SPARK PLUGS!!!

I did what Charlescrown suggested, thats heating the plugs but it did not work at the time. Probably because i didnt get them hot enough long enough. So i thought it must be something else. After no success fitting a new dizzy, I thought i'll try heating the plugs again and buy new ones the next day. If that did't work, then i will look at new PCM. I threw them back in while still quite hot and kicked her over and it started. Runs like crap so plugs are stuffed. I have bought new plugs.

Delcowizz, it did spark well and when i compared spark with new ones, there was barely any notable difference but i guess you're right when you said that they will react differently under pressure.

Anyway, at the end of the day things like fuel pump, fuel line flush, ignition module were things that i want to replace/do. Only real waste was buying a new Dizzy and time doing that.

What's a good and reliable spark plug for these motors?

I want to thank everyone of you who took the time to help and reply. I really do appreciate it

[delcowizzid]

Bpr6efs

[VTXU8]

Bpr6efs

Perfect.

[VTXU8]

Just because they spark well in atmospheric pressure doesn't mean they are not failing under cylinder pressure!

So don't beat yourself up too much if that turns out to be the issue.

-Enjoy

Thanks Gampy! Spot on

[Gampy]

Awesome, glad you got it running ...

Agreed, NGK all the way.

I have had some luck putting fuel soaked plugs in a oven set to ~300F and letting them cook for a half hour or so ...

As someone already stated (I think in this thread), it's the porosity of the porcelain in modern plugs, when they get saturated it makes it's way to the internal contacts and they fail.
The reason for the porosity is subjective, I personally believe it's a combination of lesser quality porcelain and engineered life spans, it wasn't such a problem until this new era (post y2k) ... But that's just my opinion!

-Enjoy