88 300 runs pretty rough and misses when cold. But after driving 10 minutes or so it's fine. I deleted the egr and air system. Could this be why I'm getting this? Or some other reason?

 

The tps,ect and the act sensors are used on the cold start up. The colder it is the more fuel is dumped or used. The computer uses the ect and tps up to about 160 degrees. Most people over look the act sensor but it is a vary important sensor at start up. Your timing should be advanced to help it run when it is cold. So with that being said check your timing to see if it is above what you have it set at when warm. The ect and act can be tested as it warms up and should lose volts as it gets warmer. The ohms change also as it warms up.

 

I've replaced all these sensors at some point in the past year when I had the issue of the miss that we chased down. Which of course doesn't mean anything. I'll check them this weekend if I have time. And timing is at 13 btdc

 

13* is a bit advanced. Stock is 10*. Might try that until you assure everything is working right then advance the timing again. The air system is designed to warm up the engine at cold start. That may have a little to do with the situation.

 

I set the timing back to 10 degrees. Hasn't made a difference. Would not having the air system create a miss? I could see running a little rough. But a miss?

 

I don't think it would on its own. Like you say I think the most would be a rough warm up. However it may aggravate other issues add up to the total problem. I would go back to ABC testing. Compression, vacuum, timing, fuel, spark, and systems functions.

 

I did a compression test a while back since I've had this issue. All cylinders between 135 to 150. Engine vacuum steady at 21 hg. And again 10 btdc. Fuel pressure holds at about
50. strong blue spark. All ignition components have been replaced.

 

Hmm might check for oil pressure. If its low at cold start the lifters might not pump up.

 

Oil pressures fine. I installed a mechanical gauge

 

Checked resistance as well as voltage this morning. All three sensors have been replaced in the past year. But the act did not show to spec. And also when I took out the act I could see all kinds of black crud maybe oil. This is in the lower plenum, normal?