86 Vette Barely Starts (Full Version)

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86 Vette Barely Starts

  

firedragon78 -> 86 Vette Barely Starts (9/2/2008 8:09:50 PM)

Ok,first off "HELLO EVERYBODY".I`m new to the forum and need a little help!I have an 86 Vette that tries to start,but won`t.It sometimes starts with barely an idle(really rough and lopes)buy dies after about 10 seconds.The car was sitting for about a month prior to this and at that time ran good with the exception that after it heated up the idle would go up and down.I thought this to be the fuel pressure regulator,but after hooking up a pressure gauge found it was not.Now my bigger problem is getting it to start and stay running.I changed out the cap and rotor,NO DIFFERENCE!I reset the IAC valve then checked the TPS for the correct voltage setting,which was fine.Also installed a new O2 sensor,NO HELP!I`m thinking EGR,maybe Knock Sensor or Ignition Module?I will be checking for spark,but when I changed out the cap I used a coil from my other 87 Vette which does run.Again it did not make a difference.Any help would be greatly appreciated!I`m a good weekend mechanic who knows a little and learn as I go.

  
blueshark -> RE: 86 Vette Barely Starts (9/2/2008 8:26:44 PM)

First, Welcome to the site. Glad to have ya. As for your Vette. Sounds like you''''ve checked alot as I did. From your description of the symptoms it sounds like the same thing I had with my ''''87. It turned out to be the ECM in the Dist. whether it was worn out or the grease on the bottom side had dried out I''''m not sure, but replacing it fixed the problem. I''''m not sure of any way to test them other than replacing them. Unfortunately there are so many damn things it could be that the process of elimination is sometimes the only thing you can do. Good luck with it, Cheers

firedragon78 -> RE: 86 Vette Barely Starts (9/3/2008 12:50:40 PM)

Hi and thanks for the welcome Blueshark.Yeah I`m going through the motions checking everything.Vacuum lines,electrical connectors,sensor settings and anything else I`m reading about.When you say the ECM in the distributor,you mean the Ignition Module.I found a couple online and for the price I`m going to order one and change it out.We`ll see where that gets me!Hopefully back on the road or should I say my Fiance back on the road(its her car).Meanwhile I will keep checking over everything and doing the test I can do.Any other thoughts you or anyone can offer I will gladly listen!

mech259 -> RE: 86 Vette Barely Starts (9/3/2008 6:30:30 PM)

First, unplug the MAF and which puts it in backup mode. If the car starts and idles, it probably is the problem. Lots of history with MAF on tuned port engines. [8D]

firedragon78 -> RE: 86 Vette Barely Starts (9/3/2008 7:27:25 PM)

Thanks Mech259,I`ll give it a try tomorrow.I am getting a code 34,but I put my MAF from my 87 on there and it still does the same thing.Not sure what that means,but I`ll try anything.Tried starting it again today and it had a small backfire through the throttle body.Any suggestions on this?I`ll let you how I make out!Thanks Again.Tom

mech259 -> RE: 86 Vette Barely Starts (9/4/2008 3:28:10 PM)

How many miles on the car? Can you check ignition timing? Code 34 has to do with MAF. Your supply voltage to the sensor may be the problem, so try the test I suggested.

firedragon78 -> RE: 86 Vette Barely Starts (9/4/2008 7:39:36 PM)

FIRST let me apologize for the lengthy post you are going to read![:)].After erasing the code 34 from the ECM I gave the test you suggested(Mech259) and still no change.Any idears(ideas) as to my next move?I thought about timing,but how would the timing have got so far out just from sitting for about a month?Ok,I better tell you this,prior to this I changed out the throttle body.I used the TPS,IAC and its housing from my throttle body on the used replacement one.Reason for the change?The throttle was sticking and in doing some research I found that the cause for this was a warped throttle rod.After doing this everything was running and working fine except for a problem with the engine idling up and down after it heated up.This problem already existed,so it was not a result of throttle body change.Thought it was a bad fuel pressure regulator,but a simple test with a pressure gauge ruled this out,I THINK!Did however notice that when I disconnected the canister solenoid the motor did not idle up and down so bad anymore.At this point the car sat for about a month and that leads us to where we are now,A NON RUNNING CORVETTE!

mech259 -> RE: 86 Vette Barely Starts (9/5/2008 4:37:23 AM)

Well, the next step would be to determine whether you are losing fire or injector pulse. If you have a noid light, you can check pulse by unplugging 1 injector and see if pulse goes away right before engine dies. Does the car stay running if you open the throttle and try to keep it running? Also, take a 2 - 3 ft piece of heater hose and try to listen around for a vacuum leak.

firedragon78 -> RE: 86 Vette Barely Starts (9/8/2008 7:00:41 PM)

Went away for a few days so now I am back to the testing or maybe not.I don`t have a noid light,but I am working on getting one.The motor won`t start so checking for vacuum leaks is out for now.I did however pull 5 of the plugs and found a significant amount of water on all of them.Water in the GAS,but HOW?With some further investigation(checking the gas filler cap)I found the water drain hole was plugged up and there was water laying in the filler panel.I removed the gas cap and there was water inside the filler neck and it has some surface rust.I`m guessing with the drain clogged water pooled inside and went through the vents in the cap and in to the tank.Does this sound possible Mech259?I`m going to drain the tank and the rest of the system and see what I find.The worst part is we just got that heavy rain here in Jersey so if the water got into the tank before how much more just went in again!Any ideas on how to get the fuel out of the rails?

cwb -> RE: 86 Vette Barely Starts (9/9/2008 9:47:37 AM)

Get the fuel out of rails? How much gas is in the tank?

Disconnect the battery. Get a couple of oil pans ready, and a gas can. Disconnect the filter, pull the gas cap, disconnect the fuel lines at the intake. Empty each pan into the gas can while the second pan fills.

  

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