dually running rich and randomly misfiring

Verify the Pink wire at the ignition module and the coil both have 12 volts with the key on. Make sure it does not drop below 10 volts while cranking.

2. Check the Black wire at the ignition module for a good chassis ground.

3. Back probe a lab scope on the White wire at the ignition module and see if there is a 5 volt square wave, while cranking, coming from the Vehicle Control Module (VCM).

4. If there is no signal on the White wire, check the wire for an open or short back to the VCM.

5. If the signal is present, check the White/Black wire for being broken between the ignition module and the coil.

The oil you saw under the plenum was probably leaking fuel from the cpi injector.

No CPI on the big block; uses 8 individual injectors.

Are you 100% sure you have everything reconnected? It's easy to overlook stuff like the module connection since it's sitting back there behind that huge plenum. Leave any grounds off?

When you removed the distributor did you mark both the rotor and distributor body positions? If you don't get it back in just right you'll have hell making it run right. Also, you need a scan tool that can read the cam retard figure so you can fine-tune the timing. You cannot do these with a timing light.

Sorry man, didn't know you were gonna pull lower intake or I would have warned you.

Richard

Well I had it marked but I put a new distributor in. I tried to eyeball the marks. But don't know. And I've doublechecked all the connections. And I have a snap on mt2500 scanner but not exactly sure how to even attempt the timing. But from what I read truck has to b started to do this??

That new distributor didn't come with installation instructions?

You can check this thread and maybe it will help;

Richard

No instructions

Ok so finally got the timing set and truck running. Sounds great. But smells like its running really rich. Will burn Ur eyes in no time. Cam retard is set at 0 While I was trying to set timing. At one point can retard was -38. Was dumping raw fuel thru the exhaust and a big puddle on the floor. Let run today at idle for about 20 min and gas smell is horrible. Any suggestions?? Maybe pull the plugs and 02 sensors and make sure they r good and dry?? And thanks everyone for Ur help

Cam retard set to zero while holding RPM's at least 1,000 right, not at idle?

What's your fuel pressure? Should be 58~62 on the Vortec big block.

Check the coolant temperature sensor (CTS) up at the front of the intake, if it looks old or sketchy at all just replace that SOB. It has the ultimate power to make your fuel mixture so rich it can foul the plugs and stall the engine. Any excessive resistance on this circuit will cause that and that includes bad grounds.

It definitely sounds like you have excessive fueling but also keep in mind if your cats are deleted or hollowed out you will even smell some gas under normal conditions too; people have gotten so used to vehicles with cats on 'em they forget what exhaust used to smell like. Again I'm not disagreeing with you that there's a problem that needs to be solved, absolutely sounds like one, but just saying that even when it's running right you will smell some gas if you don't have cats.

OH YEAH, also be damn sure your MAP sensor is sitting snug in the intake and that the harness connection to it is good. That's the black plastic one up front that just shoves down into the intake. The rubber boot on it can go bad, and also in this design the sensor can get crudded up with carbon. Bad (low) MAP signal will result in overfueling too.

Richard

Retard at 0 over 1000 rpm yes. Map sensor brand new no build up on it. Conection is tight seated properly. Not sure on fuel pressure. Don't have anyway to check it. Cts also looks fine. By swapping for the Bosch plugs will this make a difference as far as pressure of the amount of fuel delivered?? And since plugs and 02s got soaked. Would that give a false reading??

If you got the bosch direct replacement injectors they are plug and play. If you got ls1 you need a ecm program .o2 sensor may be causing it. Did you try to drive it an see if it would try to clear up?