Hi all, I have an 86 C4 that I haven’t started in over a year. I put a new battery in it and it has a full tank of gas. It will not start and I don’t want to just keep cranking it over trying to get it started and run down a new battery. It has started ticking after I crank it over, not sure where that’s coming from or if it’s possibly the fuel pump? Any tips on what to try to get this car running again?

 

Welcome to the forum. First thing to do is to put a fuel pressure gauge on the fitting near the injection system. You can get one at Harbor Freight for around $25 to $30. Turn the key on to the RUN position and you should get somewhere in the neighborhood of 60 psi. If you're getting no or very little pressure then it's most likely the fuel pump. The ticking noise you hear when you turn the key on could be the fuel pump but it should stop after a few seconds as it builds up the pressure before you turn the key to the start position. You could also spray some starter fluid (ether) into the throttle body while someone tries to start it.

If that doesn't produce any results then you need to check the ignition system. One way to do this is to hook up a timing light and see if it flashes on the engines being turned over. Another way is to pull a plug and ground the outer shell and see if it sparks while the engine is being turned over. A third way is to put a neon spark checker in series with the plug and the plug wire and see if it flashes.

The above information is all based on the assumption that was nothing was done to the car since the last time it ran 1 1/2 years ago.

 

Another thing I thought of after I realized I didn't know where it was stored for that period of time was rodent damage to the wiring harnesses. Since they substituted soybean oil for a petroleum based insulation a number of years ago, rodents have been known to like the new insulation.

Also you could see if there is a check engine light and pull any codes if there is one. The codes can be checked by either a scanner or shorting pin A to pin B in the OBD1 connector. This will flash the check engine light and give you the limited number of codes with that diagnostic system.

 

Hi there, I also agree with you on the rodent damage, as I am battling that right now I think. Seems like alot of my electrical is screwed up. Do you know if there is a way to replace the harness that goes to the starter or can I do this individually?

 

Welcome to the forums. I would take a good whiff of the gas tank and decide if it smells like gasoline, if not you might want to replace it. fuel filter could be an issue. You might want to consider running some fuel through the fuel lines when and if you have a working fuel pump while you have a pressure gauge hooked up. Fuel and spark it should do something. Keep us informed.

 

Some of the aftermarket Corvette suppliers have wiring harnesses available. That would probably be the easiest way.

 

On the starter wires on the 84s I think there were 4 wires that went to the starter solenoid. One was the big red (or black) cable going to the battery behind the left front wheel to the top post on the solenoid, where there was two smaller wires that supplied 12 volts to the car that had fuseable links ln there line. So it's cranking over means it has power to the igition switch. the other wire on the starter is a purple wire from the ing switch to the starter solenoid, second terminal. I would check power at the fuse box to see if it has power to the ignition with the key on. I have seen a few guys that are simplifying the starter wiring by adding a separate solenoid to the starter wiring, Its the same type of solenoid that was used on the older Ford vehicles that mounted on the inner fender on the starter side, It has 4 terminals, 2 battery posts one in and battery out, and two small terminals, one is solenoid and the other was a 12volt supply to the old style coils for starting (that we don't use much anymore). If you rewire the starter you can switch to the second solenoid method that uses one big wire to the starter only, that you can buy or make a jumper terminal that goes from the big terminal to the solenoid terminal and another big starter wire from the new solenoid to the starter solenoid. So only one wire on the starter thats only hot when the auxiliary solenoid is activated in start mode. It makes for a lot less wires to the starter solenoid. Then wire the new solenoid with the 4 wires that went to the starter originally. Cleans up the starter wiring. That might make that easier if those wires are buggered up. Or replace them, eather way. Is your gasoline usable? The injectors gum up easy on old fuel, if you use that gas run some cleaner with it.

 

Jeremy, did you ever get your 1986 going?