OK, you guys this is my first official post. I am extremely familiar with the search functions. I'm on my second ZX and just search and speculation alone has helped. I finally have to ASK though!=DD

I recently purchased a zx from a guy. backstory is somewhat irrelevant because he seems to have lied. There was a turbo valve cover on it(probably rebuilt, idk) and there was a valve cover gasket leak. I replaced it and the hose connecting the valve cover to the intake. Now she idles Extremely low and smokes white.(Never did that) I realized that if I pull ANY vacuum hose it will idle much better and stop smoking.(roughly 1,200). I initially pulled the gas gap to figure it out if i could hear any ping(which i couldnt) and she improved. so I replaced it and than i pulled this hose on the intake that he(the past owner) had plugged with a screw (which I've yet to figure where it goes. I think the black charcoal canister) to verify and yea she idles better like that, and after pulling it and letter her idle up to normal she wont even let me put it back on. meaning when I reconnect the vacuum line she idles down and dies completely till I crank her again. keep in mind.. She'll crank under any circumstance though, pulled or unpulled.
anybody know what this could be? any vacuum leak improves things? wtf!

I cleaned the injectors, afm, tps, and temp sensor with baking soda/water solution, let them dry, and added dielectric grease. they ran fine after the solution cleaning so that's maybe irrelevant, but the dielectric grease was applied at the time of the gasket and hose change, could that be a factor as well. reducing conductivity between the plugs and throwing a sensor off making it idle rough/low and put out white smoke? I thought dielectric grease was safe. I searched the forum about that as well with mixed reviews.
Hope I was thorough as could be and I appreciate the responses.

 

probably help to look up definition of dielectric. It means insulation roughly. It's use is after the connectors are put together (ie not on the contacts) to facilitate unplugging the connector, preventing moisture intrusion and stop any stray current leakage from the connector to ground. when dealing with microamps in a connector slight amounts or resistance throw things out of whack.

where did you get the baking soda water idea - wizard of oz. Use DEoxit by CAIG that is what it is made for. Spray with corrosion X afterward to reduce further corrosion.

something is major wrong if you pull a vacuum hose and it runs better. Vac leaks are the bane of the FI engine. in fact one quick and dirty check is to pull the oil filler cap when idling. if engine runs the same you got a vac leak. if engine runs worse then probably your intake system (which is how the ecu decides air flow to the engine) is properly intact and you are getting proper information to the ecu.

you might want to look up atlantic z and read their fi bible. made for earlier systems but still relevant for the zx. you got a pcv valve where it is supposed to be and working. did you download the fsm from xenon?

doesn't sound electrical but here is some general advice might save you down the line:
Get your battery load tested. Be sure you have clean, tight corrosion free terminals on both ends of your battery cables. Be sure the ground (negative) cable goes to a bolt into the frame before going to the starter. grounding through the starter is not a reliable connection. Z's don't like low voltage. causes the electronics to act funny. it is possible to have enough amps to crank but not enough voltage to run the electronics. If you have one size fit all cheapo clamp on terminals they are a problem waiting to happen.

 

I would you recommend I remove the dieelectric grease with a q.tip? (Or as best as I can?)

Lol don't knock the baking soda thing. It works great for corrosion on electrical connections. Cars or no cars.

if I pull the the oil filler cap it idles much better. That is initially how I found out that for some reason it improves with a vacuum leak

I don't understand your PCV reference I never mentioned any problems with my PCV. Yes I have the FSM, it doesn't cover my problem or symptoms. Nor does the fi bible...

If it helpsss. I replaced the battery, the starter, rotor nd dist cap, the battrry terminal connections are new too, new NGK spark plug wires and NGK spark plugs, New fuel Filter, New pcv nd hose....


Help You guys!! This is my DD. Any suggestions are appreciated!!!

 

If you have a lot of white smoke that means coolant is getting into the combustion chamber, coolant can get in through a blown head gasket, you can check for a blown head gasket pretty easily,start the car when its cool, and while the engine is running and still cool, open the radiator cap, if you see bubbles coming out then the head gasket is most likely blown.

Also everybody says not to use dielectric grease in connectors because it insulates from electricity and doesn't make a connection, or a high resistance connection.
I say use it, (that means a lot because I am a random guy on the internet)
my reasons being:
-Dielectric grease is used to protect a connection from moisture and dirt
-It will not bleed power from one connection in the connectors to all the other connections (because it cant conduct electricity)
-Any grease in between connections is scraped away by the contact upon connection leaving nothing but a metal to metal connection, and if it isn't then the connector is probably loose and needs to be replaced or you put too much grease in.

For the people who say it creates high resistance in sensitive circuits, I have used this stuff in the connectors for the resistance keys in Cadillacs where plus or minus 0.200 kohms matter and had no problem having the system work

 

I know how hard it is to find good pictures of the vacuum system so I will go down and take a few pics later tonight. I know one of the ones by that screw capped hose goes to the cruise control and another one should attach to a line coming from the charcoal canister. Are there two vac lines in the firewall close to the battery?

 

The photos I loaded are of what "my" vac lines look like.
The RED circles represent the line that goes to the cruise control.
The 2 Yellow lines go to the vacuum canister.
Green goes to the Charcoal canister
White... well so far white just hangs around. I haven't figured that one out yet.

 

Its a 79 base, so there's no cruise control. The pictures you took match the intake from my 83's p79 intake. not my 79's "n47?" Intake. So close though. I'm thinking it's a blown head gasket like he said.I gave in and took it to a shop for a diagnosis. I'll see what they say, after that do the head gasket since it's just a $20.00 + time and patience investment.

Its just my first head gasket change and I see you guys and my haynes talk about the wedge and messing the timing up, I don't know. Its kinda intimidating.