Welcome to the Connecticut Z Car Club Forums




Username:  
Password:  
Log me on automatically each visit
Register 
It is currently Fri Dec 02, 2022 9:02 am
Welcome to the Connecticut Z Car Club Discussion Forums   
If you have trouble logging in or encounter any issues, please send an email to webmaster@ctzcc.com.

All times are UTC - 5 hours





Post new topic Reply to topic  [ 9 posts ] 
  Print view Previous topic | Next topic 
Author Message
 Post subject: Need a specialist
PostPosted: Wed Sep 21, 2022 3:41 pm 
Offline

Joined: Thu Dec 02, 2021 11:35 am
Posts: 12
Well we have rebuilt our 1980zx from the ground up and she looks great. BUT we cannot get her running just right. We have done all the self diagnostics we are capable of but need an expert at this point. I am looking for a few shops in the area that I could take her to get the engine fine tuned. Our last job was to recoat the fuel tank. We have good vacuum 17 and fuel pressure is at 37 and holds well. All new injectors. Timing is 8 advanced. She fires right up but is sending out white smoke and after she stops she will not start again for an hour or so. I am thinking valves or leaking head gasket or rings.
Thanks


Attachments:
IMG_8763 (1)_edited.jpg
IMG_8763 (1)_edited.jpg [ 883.64 KiB | Viewed 503 times ]
Top
 Profile  
 
 Post subject: Re: Need a specialist
PostPosted: Wed Sep 21, 2022 4:37 pm 
Offline

Joined: Wed Apr 09, 2008 5:53 pm
Posts: 14558
Location: CT
Disclaimer: I'm not an expert on Fuel Injected cars (but I slept at a Holiday Inn last week).

Yes, white smoke is usually water (coolant) leaking into the combustion chambers thru a gasket. (Or more seriously, thru a crack in the head or block). Bad rings or leaking valves would give you blue smoke (burning oil) and over-rich fuel mixture would give you black smoke.

Check your compression, looking for low pressure in one (or two adjoining) cylinders. Look at your oil for signs of coolant pollution. Check your radiator for signs of oil ingestion. If either fluid looks like a frothy milkshake, you have a leak somewhere.

Still pondering the hour-long wait to restart. :? Does your temperature gauge read normally? Maybe the gasket only leaks at operating temperature and the car will start as soon as the head/block cool off enough to mate properly again.

Other opinions from the Clubbies, please?

Frank T

_________________
1970 240Z


Top
 Profile  
 
 Post subject: Re: Need a specialist
PostPosted: Sun Sep 25, 2022 9:11 am 
Offline

Joined: Wed Jul 23, 2008 2:38 pm
Posts: 3354
Location: rhode island
I really doubt you will find a mechanic who knows how to actually fine tune it, but simple basic engine operation is the same. For one, white smoke is not good. A leak down test of the engine should be top priority before doing anything else. They sell the gauge at NAPA. All you do is pump air in each cylinder at TDC and see how much leakage you have by the gauge. If there is excessive leakage then you look and listen.......Bubbles in radiator will tell you there is a head gasket leak, Air out of dipstick is bad rings or hole in piston, air out intake is bad intake valve and bad air out exhaust pipe is bad exhaust valve. Machine shop SHOULD have pressure checked and milled the head. If not, that's leaves alot to wonder. If you want to know you have fuel, just take top hose off filter, put it in bottle and turn the key to watch fuel, it should be like a garden hose, not a trickle. Fine tuning is just that, it has to run fairly decent before fine tuning.


Top
 Profile  
 
 Post subject: Re: Need a specialist
PostPosted: Sun Sep 25, 2022 9:39 am 
Offline

Joined: Mon Jun 30, 2008 2:16 pm
Posts: 1074
Location: Ansonia, CT
Let me first say that your engine bay is one of the most impressive I've seen. You have gone above and beyond restoring all the hoses, lines, and metal parts on this build. :thumbs_up: Where did you get all of the cad plated metal lines done? They look fantastic.

Paul's advise to you looks right on. I wish I could help, but my knowledge rests more on the old 240Z hardware, but mechanically the fix for the white smoke issues in either Z series would be similar. I trust that you had this smoke issue even after the engine has run for awhile? It's not uncommon to see white smoke coming from the exhaust on a cold car that has been sitting awhile when the pipes are cold and the condensation evaporates from the warming exhaust system. The not starting when hot issue could be a vapor lock issue. I've seen some Z cars that had insulation installed on the fuel supply rails (metal lines) to help prevent that issue. Some Z's even have a small fan blowing on the rails to help prevent the vapor lock when the car is shut off.

In any event, I wish you luck in getting your precious Z car sorted out.

_________________
John Kish
1971 240Z - original owner


Top
 Profile  
 
 Post subject: Re: Need a specialist
PostPosted: Sun Sep 25, 2022 3:50 pm 
Offline

Joined: Wed Apr 09, 2008 5:53 pm
Posts: 14558
Location: CT
I considered vapor lock too, but he has fuel injection.

_________________
1970 240Z


Top
 Profile  
 
 Post subject: Re: Need a specialist
PostPosted: Wed Sep 28, 2022 3:51 pm 
Offline

Joined: Thu Dec 02, 2021 11:35 am
Posts: 12
Thanks for the input all! It turned out to be the new fuel pump was not holding pressure so I put the original back in and presto held right at 32PSI. The white smoke was from a bad cold start valve. It was not stopping and flooding the engine with fuel. I noticed the plugs were all fouled with black soot. So I disconnected the cold start and presto again, she has never run better.


Top
 Profile  
 
 Post subject: Re: Need a specialist
PostPosted: Wed Sep 28, 2022 3:53 pm 
Offline

Joined: Thu Dec 02, 2021 11:35 am
Posts: 12
John,
Thanks for the engine compliment. Reliable Plating in Bridgeport did them for me. Very reasonable.


Top
 Profile  
 
 Post subject: Re: Need a specialist
PostPosted: Wed Sep 28, 2022 10:21 pm 
Offline

Joined: Wed Apr 09, 2008 5:53 pm
Posts: 14558
Location: CT
I love stories with happy endings! :D

Zee you at the meeting JS!

Frank T

_________________
1970 240Z


Top
 Profile  
 
 Post subject: Re: Need a specialist
PostPosted: Tue Oct 04, 2022 7:31 am 
Offline

Joined: Wed Jul 23, 2008 2:38 pm
Posts: 3354
Location: rhode island
Well I guess that would do it, you had grey smoke then, not white smoke. The fine tuning is within the AFM and I can do it by ear, but having a CO machine is helpful.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 9 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  









Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
mile200 v1.0.1 designed by Team -Programming forum- .