Corvette C4 Forum 1984 through 1996

86 Vette Barely Starts

Thread Tools
 
Search this Thread
 
  #11  
Old 09-09-2008, 09:27 PM
mech259's Avatar
Super Moderator
Join Date: Jan 2006
Location: Lumberton, Texas
Posts: 1,858
Default RE: 86 Vette Barely Starts

You can bypass the fuel pump relay and put a drain hose to your fuel pressure test port (remove schrader valve) , then run fuel into a drain pan to see if there is water.
 
  #12  
Old 09-09-2008, 11:09 PM
firedragon78's Avatar
Thread Starter
Join Date: Sep 2008
Location:
Posts: 13
Default RE: 86 Vette Barely Starts

Yeah I figured bypassing the fuel pump relay to pump the gas out would be the way to go,but was going to pull thefilter like CWB suggested.Mech259`s way sounds like it will get the fuel out of the rails as well as the rest of the lines and tank.I`m going to follow both of your procedures as I figure once the gas tank is empty the lines will still have some gas that will need to come out.This forum is excellent and your help is greatly appreciated.
 
  #13  
Old 09-10-2008, 09:05 PM
firedragon78's Avatar
Thread Starter
Join Date: Sep 2008
Location:
Posts: 13
Default RE: 86 Vette Barely Starts

Hi guys,pumped the gas out through the schrader valve and got about 5 gallons of what looked like skim milk.Going to pull the fuel filter and empty the lines out tomorrow.Gonna go with new plugs and filter,refuel her up and hope for a running vette!Let ya know tomorrow night.
 
  #14  
Old 09-12-2008, 02:47 PM
mech259's Avatar
Super Moderator
Join Date: Jan 2006
Location: Lumberton, Texas
Posts: 1,858
Default RE: 86 Vette Barely Starts

Hope you don't have any trash stopping up the injectors. Good Luck! [8D]
 
  #15  
Old 09-14-2008, 08:14 PM
firedragon78's Avatar
Thread Starter
Join Date: Sep 2008
Location:
Posts: 13
Default RE: 86 Vette Barely Starts

Well got everything cleaned out,HOPEFULLY!Cars running .but not great.Think I need to change out the IAC valve.It idles up and down,and about 10-20 seconds after start up I can hear the air from the air cleaner going into the air ducts get louder(like a loud vacuum noise).I have read some similar forums with the same problem and they seem to all say the IAC or EGR.What do you guys think?I figure it can`t hurt to change the IAC first as theEGR is under the plenum.If I take that apart,I`m replacing the Fuel Pressure Regulator and EGR.Is there a test for the EGR that can be done?Also pulled some of the spark plugs and no sign of water.Oh and Mech259,I hope there is no trash in the injectors too!Guess if I pull the Plenum,I will either get the injectors cleaned or replace them.
 
  #16  
Old 09-15-2008, 06:05 AM
cwb's Avatar
cwb
cwb is offline
Senior Member
Join Date: May 2007
Location: eastern NC
Posts: 1,567
Default RE: 86 Vette Barely Starts

Now that you're running, do some tests before replacing stuff.

Test the fuel pressure static (motor off), at idle with vacuum on FPR, at idle with vacuum off of FPR, and pedal down pressure (you gotta' tape the guage to the windshield to read pressure and make sure it's enriching at full throttle).

Then check for vacuum leaks:
How do you know it didn't have an effect?

Did you put a brick on the gas pedal? Block the throttle body arm?

What did you do, before you sprayed the carb cleaner, to increase the idle to a STEADY idle, WHICH YOU HAVE TO DO, so that you know when the carb cleaner has hit the leak that you have???

I suggest you do it again, and spray JUST A LITTLE AT A TIME, and wait for the spray to dissipate, before hitting another TINY spot. ...
 
  #17  
Old 09-16-2008, 03:58 AM
firedragon78's Avatar
Thread Starter
Join Date: Sep 2008
Location:
Posts: 13
Default RE: 86 Vette Barely Starts

I did the fuel pressure test and all was as it is suppose to be.I didn`t try the vacuum off the FPR so I will give that a try tomorrow.Checked all vacuum lines and they seem to be fine too.Checked PCV and thats ok(actually brand new),but made sure it was ok.I did think of doing the carb cleaner test,but gotta get the carb cleaner.I bought a new IAC,but haven`t installed it yet.Trying to get some work done on my boat,a few house projects and therapy for a recent back surgery limit my time as well as range of movement.Hope everybody is doing better than me!
 
  #18  
Old 09-21-2008, 11:11 PM
firedragon78's Avatar
Thread Starter
Join Date: Sep 2008
Location:
Posts: 13
Default RE: 86 Vette Barely Starts

Took a few days off due to my back.I put the new IAC on and started replacing some of the rubber vacuum lines.The old ones seem to be very dry and there is some noticable dry rot(cracking) in the lines.The motor is still running rough and the idle goes up and down at idle.Now there is a real bad bog at acceleration.Mostly on the start,but picks up and goes after a few seconds.Did the carb spray test and did not get any signs of a leak on the intake,vacuum lines or fuel related parts of the engine.Next I guess would be a test or replacement of the EGR Valve and if I do that I`m pulling the fuel pressure regulator to put in a new one.Can`t seem to find a new EGR valve solenoid.Any other ideas,ANYBODY?This car is driving me nuts![sm=wtf.gif].
 
  #19  
Old 09-22-2008, 07:10 AM
cwb's Avatar
cwb
cwb is offline
Senior Member
Join Date: May 2007
Location: eastern NC
Posts: 1,567
Default RE: 86 Vette Barely Starts

You're loping idle is a vacuum leak.

How do you know it didn't have an effect?

Did you put a brick on the gas pedal? Block the throttle body arm?

What did you do, before you sprayed the carb cleaner, to increase the idle to a STEADY idle, WHICH YOU HAVE TO DO, so that you know when the carb cleaner has hit the leak that you have???

I suggest you do it again, and spray JUST A LITTLE AT A TIME, and wait for the spray to dissipate, before hitting another TINY spot. ...
 
  #20  
Old 09-24-2008, 11:15 PM
firedragon78's Avatar
Thread Starter
Join Date: Sep 2008
Location:
Posts: 13
Default RE: 86 Vette Barely Starts

Alright,I threw a brick on the gas pedal and got the car idle up to about a steady 1400 rpm.I then sprayed small amounts of carb spray along the intake,the top and bottom of the runners,the throttle body,all vacuum line connections and hoses and I`m sure other places that I thought to spray,but no change.I put on the new IAC(correctly as the book said to do)and the car seems to be running better with a very small amount of idle lope.I also reset the minimum idle speed and the TPS.Its still running a little rough,but has a major amount of bogging when hitting the peddle.It is fine if I bring the idle up slowly.Oh and now for some reason when putting the car into gear it goes in kinda hard,like the idle is too high,but its not!Any other things I should look at?I`m thinking the fuel injectors might have an issue due to the water in the gas.Going to try the EGR test next or maybe throw that brick through the window!
 


Quick Reply: 86 Vette Barely Starts



All times are GMT -5. The time now is 04:00 AM.