Hi again, to start with I'm really thankful I have Corvette Forum to turn to when I need help with my '85. Putting in a new fuel pump solved my previous problems, thanks to all who helped with that. Yesterday I'm driving on the freeway and the cruise control starts to loose mph. After going down about 10 to 15 mph it kicked back in and was ok for a few minutes then it happened again. Then next thing I noticed was the display on the dash that I normally have switched to coolant temp was now showing me voltage even though the switch was still on coolant temp. I turned the switch to off and it still showed voltage with a red square box next to the voltage. When I got home I pulled it in the garage and went in the house. A few minutes later I heard the fan running on the car. I opened the hood and found it was not the fan I can see facing the motor instead it was the fan(s)? in front of the radiator. I have never heard these fans run before and even though the car was turned off they ran for about 5 minutes before shutting off. The other main issue is that when I go to start the car the starter sounds like it's not getting enough power because it just barely turns the motor over. This has happened in the past but very rarely. It almost always cranks over fine. Is there anything I could have screwed up when I put the fuel pump in? The pump is working fine and there was just the two wires to the pump so i'm sure I got those right. Lastly, when I disconnected the battery last night I heard a clicking sound in front by the fan(s) in front of the radiator. Each time I touched the ground cable to the battery I could hear the clicking. There must be a solenoid or relay that I'm hearing but I'm wondering if that is part of the problem. Any thoughts would be greatly appreciated. Thanks, Jay

 

How old is the battery?
Check the voltage. These cars do not like it when battery voltage is low....electronics do strange things with low voltage.
Check both battery cables for corrosion; pull back the red and black plastic boots and check the cable ends.
Check the positive cable at the starter connection.
Also check the connection at the distribution box.
Check the negative cable connection to the frame.
And if you can, check the negative connection(s) to the engine.

Good luck.

 

Thanks Lanny, I don't know how old the battery is but it turns the motor over very fast on almost all occasions. I will have the voltages tested today. Also, where is the distribution box?

 

The reason the dash switches to battery voltage and shows the red rectangle is because the battery voltage is too low (I think it trips at 11.5 volts). You should see roughly 14 volts if everything is OK (over 1000 RPM -- sometimes it's lower at idle because the alternator doesn't work well at such a low RPM).

It sounds like your alternator is bad or there is a wiring problem. This recently happened to me and I took the alternator apart, found nothing unusual, put it back together and haven't had a problem since (two months). Apparently there was a bad connection internally.

 

Hi Cliff, I got a 120 amp alternator at Carquest today and put it in. That brought my volts up to 13.8 so I figure that will do it as far as electrical issues at this point. I'm going to take it for a 2 hour drive in rush hour this afternoon so that will be a good test with the air on. I appreciate your wisdom. Thank, Jay

 

Hi Cliff, I have another question about my '85. This is a problem I thought I had solved by putting a new fuel pump in. My car doesn't start for a long time either hot or cold. It cranks and cranks but doesn't fire for 10 to 15 seconds. I can't figure out what's going on. It acts like it isn't getting any gas. Here is a list of parts that have been replaced in the last 6 weeks; Fuel injectors, fuel filter, fuel pressure regulator, fuel pump, plugs, alternator, idle air control valve, EGR control valve relay solenoid, and this is my second tank of premium gas. I used to use regular. Can you think of any other reason the car won't start well? If I hold the peddle to the floor then turn the key it starts but runs loaded up for a few seconds. Any thoughts would be appreciated. Thanks, Jay

 

okay so we figured out why your battery is low and what happened to your alternator. When cranking the engine over for such a long period of time it drastically reduces the stored power in your battery, its almost enough to drain it by what your describing. The alternator recognizes that the battery is low and begins to run overtime. This will burn out your new alternator in no time. You need to diagnose the slow start issue or you will kill your new alternator and battery all over again. These alternators where never designed to recharge a battery they where only engineered to maintain a battery. Good luck, I hope you find out what is causing the delayed start. Have you investigated your injectors yet?

 

coolant temp sensor causes what you describe. or fp regulator leaking into the vac line. engine running rich, but starts in clear flood throttle position.
remote: timing retarded, fp relay not working. does it prime for 2 seconds when you turn key to run? if so, relay is ok. sounds like temp sensor. the only thing you didn't replace. joking, joking.

 

I have a '96 so I am not completely sure but I believe 1985's have a cold start injector on the drivers side of the intake. This could be bad and causing your problem. They are not made anymore but can be found in salvage yards online. I believe there are also threads about it.
Good luck.

 

Thanks everyone, for the sake of the alternator and battery I will probably do the flood start when starting the car until the real problem gets fixed. From what I read about the fuel pump relay, the fuel pump won't work of that relay is bad. Mine clicks when the key is turned on and the fuel pump runs for a few seconds to send fuel forward. I put a new fuel pressure regulator on when I did the injectors since it was that far taken apart but the old FP regulator diaphragm looked still good. I'm not sure if it would be leaking into the vacuum line? The coolant sensor is sure worth investigating. I will have to read up on what it does and where I can get one and most importantly, how much it costs. A local mechanic who primarily works on muscle cars said the first thing he would check is the timing. I no longer have a timing light and he gets $90 an hour so I haven't checked that out yet. That could be why it runs hot though. Sometimes I think if I win the lottery I would just take the car to the Chev dealership and have them keep it until it's fixed. Then the light bulb goes off and I think if I won the lottery I would just get a 2012 Corvette. I guess that would mean I would have to start buying lottery tickets. I will keep you all posted on what transpires. Thanks, Jay

 

My battery keeps going dead on my 87 c4. I've had the year old battery changed (under warranty), car ran till the battery died. Had MY mechanic change altinator (reman) drove fine till battery died again. Any ideas? I am not mechanically inclined at all so any suggestions will be greatly appreciated!!

 

best to start a new thread but I would check and clean your battery connections and if yours has a fuse box or block by or behind the battery I would think there.