1985 corvette won't start
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From: MERIDIAN MS
1985 corvette won't start
1985 corvette that has setup for several years had water in the fuel system. I have changed the following items: Fuel pump assembly, cleaned tank and all lines, ecm module, fuel filter, all injectors except csi, rebuilt fuel regulator, checked injector connections with noid tester for interm flash and they did except for CSI did not, check fuel pressure 43 to 55. The car will start with spray in intake but stops after all gone, engine tries to crank but no result. Only thing else i could see is change sensors now.....got any ideas??? I have the dash module out for repair, i guess that has no effect on the engine operation or does it? Help.......
Last edited by FreddyJay; Nov 11, 2013 at 02:05 PM.
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From: MERIDIAN MS
1985 corvette won't start
I checked the injectors and they were flashing....but the CSI did not flash it was a steady lite.....also check all fuses---ok. I know that they discontinued the CSI so that is a another issue...
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From: MERIDIAN MS
I am going to check the plugs to see they are wet and where is the cold start fuse located and does it have a relay as well. I they are located other than the fuse panel please point it out so i can check. Can any of the sensors (map, mat or tfi) cause any of these problems
Safety Car
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certain (80F? ) engine temp controlled by a switch when the engine is cranking over
The switch that operates the CSI is at front of intake next to the CSI
Last edited by vetteoz; Nov 12, 2013 at 04:37 PM.
Safety Car
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1st you say it will run on spray so it must be cranking over in order to fire up , then you say it will not crank over ??????
So do you have a cranking problem or a starting problem or both ?
Safety Car
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you are currently asking as well as circuit diagrams and detailed diagnostics.
Consider it a almost essential piece of equipment for your toolkit if you plan on doing your own work
Also available on a Cd so you can print out what pages you want , no greasy fingerprints on the book
Last edited by vetteoz; Nov 12, 2013 at 04:56 PM.
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From: MERIDIAN MS
Well lets do this again, the car will start with spray in the intake and stop when the spray is all gone. The engine turns over fine but will not run....spitts and spotters never runs on its own. Has 43 to 50 on fuel pressure, new injectors, new ECM MOD, has new gaskets in fuel regulator, flashed each injector with NOIM TESTER, new fuel assy in tank and cleaned out tank and refueled. new fuel filter.....what else can i check ??????
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From: Whitefish Falls Ontario
St. Jude Donor '08-'09
Sounds like you need to check the fuel pump relay.. When you first turn the key on, do you hear the relay operate?? If you apply 12v to G of the ALDL do you hear it run?? Do you get 12v to terminal D of the relay?? If you have 12v to D the pump should run, if the pump doesn't run check terminal A of the relay, if no 12v get a new relay.. It sounds like when you crank it over, the time is long enough to operate the oil pressure switch, which should operate the pump.. If not you need to check the fusible link that feeds the switch and terminal E of the relay.. Is the pump fuse good?? 
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From: Anaheim CA
What exactly does that mean? Did you use a noid light or something else?
For reference, there are two ways to check injectors (probably more, but we'll go with this for now):
Noid light: unplug injector connector and plug the light into the connector. Then crank engine -- the noid light should flash.
There is also an electronic injector pulser that plugs into the injector and applies a signal to the injector to get it to pulse.
For reference, there are two ways to check injectors (probably more, but we'll go with this for now):
Noid light: unplug injector connector and plug the light into the connector. Then crank engine -- the noid light should flash.
There is also an electronic injector pulser that plugs into the injector and applies a signal to the injector to get it to pulse.
Melting Slicks
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If you have pulses with your noid light but it won't start, pull out your injectors and see if they are flowing fuel. If they are flowing you maybe be dealing with them flowing too much or too little. Since you say you can get a response with starting fluid, I imagine it isn't giving too much fuel.
So, see if they are flowing. If they aren't flowing then they need to be replaced.
If you don't get a pulsation to them then you need to trace back as to why they aren't.
Typically, computers relay on a RPM reading before it will fire up. The injectors are EFI, not SFI, so there should be 2 wires at the ECM that control the injector pulses. Go all the way back to the terminals on the computer and test to see if you're getting a pulse. If you get a pulse there, then you have a bad wiring connection.
If you don't get a pulse there, then I would investigate the distributor module and pick up coil as AGENT 86 suggested. That should send a RPM reading to the ECM. Make sure you are getting a reading there, if you aren't then there is your problem.
Here is wiring diagram that should be able to help you with the pick up coil.
So, see if they are flowing. If they aren't flowing then they need to be replaced.
If you don't get a pulsation to them then you need to trace back as to why they aren't.
Typically, computers relay on a RPM reading before it will fire up. The injectors are EFI, not SFI, so there should be 2 wires at the ECM that control the injector pulses. Go all the way back to the terminals on the computer and test to see if you're getting a pulse. If you get a pulse there, then you have a bad wiring connection.
If you don't get a pulse there, then I would investigate the distributor module and pick up coil as AGENT 86 suggested. That should send a RPM reading to the ECM. Make sure you are getting a reading there, if you aren't then there is your problem.
Here is wiring diagram that should be able to help you with the pick up coil.
Instructor
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Rookie 2 cents
Your issue sounds very similar to the one I had a months ago. I swapped the fuel pump ignition relay, and purchased a piggy back unit that sends a signal to the cars computer to continue to fire the injectors after start up. That worked for me. Good Luck
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From: Anaheim CA
I agree with Agent 86. I think your problem is in the distributor or its connection to the ECM.
Last edited by Cliff Harris; Nov 15, 2013 at 03:03 AM.
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From: MERIDIAN MS
Holy Cow, the car has fixed its self, I went down the other morning to troubleshoot the wiring and after checking the fuse again, I hit the key and it started, but I did notice that the fan temp sensor was not working and I believe I will wire it to run when the key is on to prevent over heating and more problems.
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From: Anaheim CA
If your car has an auxiliary fan (in front of the AC condenser), then that is controlled by a thermal switch in one cylinder head. On '84 and '85 cars that switch is in the passenger side head between spark plugs #6 and #8. Starting in 1986 the switch was moved to the driver's side head between spark plugs #1 and #3.
Last edited by Cliff Harris; Nov 19, 2013 at 05:34 AM.
Intermediate
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From: Maple ridge BC
Car is fixed.
Not sure if this is my original user name, but I started this thread. Turns out all injectors where shot and the fuel rail was full of water/sludge when the sending unit gasket let rain inside the tank. When I tried to start the car years ago, the pump sucked up bad fuel with water in it, the car wouldn’t start and it filled the rail with water.
then because the car sat for a year or two before I started working on this, it crapped out the fuel pump.
so as stated, I changed the pump, had pressure at the rail. Still no start.
rented a mood light and I had pulse.
so I bought injectors and upon removal found them with rust on them and in the rails.
after I change the injectors the car started up. Drove it a couple hundred miles, no water showing up in the oil anymore. All is good.
thanks for the help everyone.
then because the car sat for a year or two before I started working on this, it crapped out the fuel pump.
so as stated, I changed the pump, had pressure at the rail. Still no start.
rented a mood light and I had pulse.
so I bought injectors and upon removal found them with rust on them and in the rails.
after I change the injectors the car started up. Drove it a couple hundred miles, no water showing up in the oil anymore. All is good.
thanks for the help everyone.
