Hello all, just pulled the plug and bought a 85 vette, with a problem. Car is beutiful, 81k original miles, incredible condition, only paid 3700 for it, even has new tires. Here is the catch, will not start, cranks over fine, has good compression. I bought it because I believe it is just the vats system. My question are:

1) when you put the key in the ignition, the security light blinks (I assume it is the wrong key) does the light come on and blink normally or is this as I suspect the vats working and that they are the wrong keys? (the guy I bought it from bought it in this condition and had no idea what could be wrong.) Oh yeah, it cranks, but no start.

2) on the 85 c4's, do the keys have the visible pellet resistors, because both keys he has, or I have now, look like standard hardware store keys with no type of resistor visible.

3)If they are indeed the wrong type of keys, can a dealer look up the necessary resistance number through the vin for a new key?

Thanks for any help, I 'spose you will be seeing a lot of me here, and some pics soon.

 

85 has no VATS. Do you have spark? How is the fuel pressure? The list goes on and on but you can count VATS out of the equation.

 

If it cranks over, then it's not the alarm system. You'll need to check for spark and fuel.

FWIW, VATS is just the resistor key. 85s don't have VATS, but they do have a full fledged theft deterrent system.

 

hmmm, everywhere I was reading it said the vats was on the 85 here is one of the links (you may have to copy and paste), I am not doubting you guys, just kinda bummed that I got this information from various sources and was pretty pumped thinking the guy just had the wrong keys lol. I guess that is kind of good though, cause I can do the usual spark, fuel air checks to see what is up, are there any things on the 85 I can look at first? I actually don't have the car here tonight, it was too late to get a trailer, wasn't planning on buying but when I saw the condition of the car I had to make a move.

http://www.motorage.com/motorage/dat...09/article.pdf

 

That's odd, maybe its just a typo in the article? '85 has no VATS.

I have an '85 also and it sounds like your anti-theft is working like it should (the way you describe the light blinking).

So... look at the next cause...

you need air/fuel/spark... something is missing.

 

If I suspect no fuel I do the quick test...spray some starter fluid into the intake and see if it fires. If it does then you have a fuel problem. If not check the spark. You can do spark first if you have no starter fluid on hand because it would be easiest and cheapest. A few summers ago my bosses truck would not start and we had isopropyl alcohol on hand so I used it as starter fluid. The truck fired right up so I told him he had a fuel problem and it turned out to be his fuel pump. Works for me.

 

As stated the 85 vette doesn't have a pellet in the key. If it cranks then you have the right key and the security light flashes anytime the door is open. If it cranks and doesn't start the first thing I would check since it's new to you is the fuses. There is a crank fuse, injector fuses, fuel pump fuses, ect. Things that would not complete the circuit.

Now when you turn the key to the on postion do you hear the fuel pump in the tank prime, like a humm, for about 2 sec. If not I would start there. You will also need to check for spark and check fuel pressure.

For spark I will get a spare spark plug and remove a wire one at a time and put the plug in the wire and hold it up about 1/2" for the exhaust manifold while someone cranks on the engine. You may want to remove the injector or fuel pump fuses for this test. You should see a blue spark and if your fingers are in the wrong place might even feel it.

You will also need a fuel pressure guage , that can be gotten at just about any autoparts store for $40. It will be attached at the Schrader valve one the passenger side fuel rail, looks like a tire valve stem. It just screws on, and when the key is in the on position the guage should read approx. 40 psi after you hear the pump prime.

 

Okay, this is what I have so far, bought a code scanner, comes up with 12, which is all okay.
Had some starter fluid on hand but no guage yet, (when I stopped at the store I didn't have the car yet to make sure I got the right one) I was at a friends shop, I have a rec. showing the fuel pump replaced not too long ago, plus my partner said he heard the hum for about 3 seconds....

But, after letting the pump shut down and with the key on, we pushed down on the schraeder valve and gas barely trickled out, not really any kind of pressure.

At this point I wanted to spray some starter fluid to see, but he said the computer wouldn't fire without recognizing a signal from the injectors so I didn't try.

I stopped on the way home, bought a new pump relay for gigles, a new filter, a pressure guage and cheap a** manual.

I am going out to unload the car from the trailer and will check the pressure, try the starting fluid and report back.

I will also post a couple of pics (if the sight will let me since I am a junior lol)

Thanks for you're help all

 

No, he's got it backwards. The computer won't fire the injectors if it doesn't see spark.

 

Correct CC

The gas barely coming from the Schrader valve isn't good. It should have a little force/pressure behind it. I would get the guage on there and see if pressure reads 36-42 psi after the key is on, then turn the key off and watch pressure, if it drops you have a leak in the system. Also use a basic test light and test the injector connectors while someone cranks the engine, just to see if you are getting signal to the injectors.

 

Okay, she is unloaded and in her room lol, anyway, when the key is turned on the pressure reads 40 psi, I also noticed that after a bit of cranking the oil pressure reads up to 30 psi. Anyway, although it turns over, the battery is only reading 9.5 volts at most and and completely shuts off all lights and dims the or shuts off the dash. I am going to put a new battery in it for giggles.
As for the starting fluid, it did nothing, so, I guess I will move to check the spark issue. If the ecm or ccm were bad, it would show more than just the 12 code right?

 

Put in new battery, seems to me there is no spark, gonna check that out tomorrow, but, put the code scanner back in came up with new code
Now along with 12, it pulls up 54 according to my little code book:

low fuel pump voltage
Or
fuel pump relay

or

egr solenoid no.2 failure

or

quad-driver module output failure

or

mixture control solenoid- circuit voltage too high

any of these likely to cause a crank/no start issue?
I did notice when cranking it with the new battery, I definitely could smell the fuel.

Thanks in advance

 

Make sure you have good fuel in the tank. Mine sat for like two years and was just full of gas.

Would not hurt to drain the tank and get some good clean stuff in her.

Ya just never know. (But no spark does not help either)

K

 

looks like there is spark, not sure if it is as strong as it should be, but it is there.

My next question would be, when I turn on the car, I hear the pump kick on, off after about 2 sec. But if I leave the key on, go to the schraeder on the fuel rail and let the pressure off, it does not continue to come out but rather the initial fuel comes out then nothing, could this be the fuel pump relay causing problems?

Although it doesnt start when I spray some starting fluid into the the very front of the aircleaner assembly. I had to spray it and then go to the key as I was checking by myself, it did sound like it would almost like to start but not quite. If the coil were bad, could I be getting some spark but not powerful enough?

Next I guess will be a compression check, but at 96k miles I would think this shouldn't be a problem.

I swapped out the pump relay and fuel filter for fun, not much different. I did notice, on checking the pressure in the rail, when I first checked it it went up to only 30 psi this time. It dropped to 20 after 5 or so minutes. After waiting I checked again, this time it went to 40, but then I heard a small pop or cracking kind of noise and the pressure dropped 12# or so in less than a minute. Couldn't pinpoint the noise cause it was too quick, but sounded like up passenger side front of motor. Pump? injectors? Anything coordinate with the code 54 + crank only no start?

its late, I've been drinking, but here is the latest, test light on injectors, light is on as soon as I touch them, but does go from bright to dim, (blinking) while cranking, is this how it should be?

Also put the light on the fuel pump source, light comes on for two seconds or so when key first turned on, but despite relieving pressure, do not run the pump again, could it be as easy as the fuel pump?