Blackcorvette_85

So Im thinking this may be a ground issue, but hopefully someone has been thru this before and can point me in the right direction. so quick history, car sat for a few years outside in the pacific nw, ran fine when parked. My plan was to paint it and redo the interior and I started tearing it down to do that, then life got in the way and it had to sit. what ive done so far. new battery, new fuel pump,fuel filter, pumped out tank, replaced injectors with bosch 3's, replaced all fuses in the panel, cleaned up battery terminals and one chassis ground. so once I had all the fuel stuff done, figured it would start, getting 42 psi at the rail now when turning key to on position, but it would just turn over and not even act like it wanted to start. pulled a spark plug wire off put a screw driver in it, no arc. pulled cap, inside looked good, but still cleaned all contacts, checked and rotor was spinning when cranking. pulled coil and got point 7 ohms resistance at the wires and 7.6k at the secondary, so I think thats good. Now where it gets weird. with they key in the on position almost cranking I get 12v at the coil, but as soon as it starts to crank, it drops down to like point 2 volts. I tried running a jumper wire from the battery to the coil to keep the voltage and turned it over and the engine sputtered a bit for the first time, but wouldnt start. I tried to check for spark again to be sure, but my starter started clicking, which is weird because I havent strained the new battery much and even with a battery charger on it set on high its still clciking, thats why Im wondering if it could be a ground issue. still have 12v at the battery. I read thru a bunch of the no spark posts and havent gotten any new ideas, help! lol

Randy M

I had an ignition module fail once and it sounds like this may be your issue. It is in the distributor under the rotor. In fact, the first replacement didn't work either. Talk about frustration. You may want to check it out.

Another thing I have seen where the rotor and cap can get pin hole blown in them. You might want to replace them.

ghoastrider1

I once had the gear pin shear down my the cam. The inside wasnt turning as I cranker her over.

Blackcorvette_85

well I ordered new cap, rotor, coil and module just to be sure. Cant hurt to replace them. so should know wednesday. Still kinda wondering if maybe the starter or solenoid is shorting out or I have a bad ground somewhere

ls777z

Make sure your battery and starter connections are tight and clean. Check the wiring for burns, signs of being shorted out, patched,etc.

yd328

Check the grounds, also if there has been any crimped connectors or scotch locks in the wiring check for bad connections. I have seen those do as you describe with the voltage drop due to corrossion or in the scotch lock case, wires fraying.

Gary

Blackcorvette_85

Getting so frustrated! So I just replaced the cap, rotor, coil and module and still doing the same thing. Could really use some ideas. Ive cleaned the battery terminals well and I still am losing all voltage at the cap when I crank it over,but it does crank over. I have 12vs with the key in the on position, but as soon as it starts cranking in drops to almost nothing. It seems like it must be grounding out somewhere to me or some kind of short. Does anyone have a wiring diagram for the ignition and also the location of the main grounds or any other suggestions, gonna lose my mind at this lol. Gonna have to crawl under this thing im guessing to clean the grounds up and im kinda claustrophobic so that should be fun, but would really like to know exactly where they are first so I can get it done as easy as possible...

kael

Load test the battery, most auto parts places will do that for free. I wouldn't expect that a bad battery could turn the starter but not fire plugs, but your voltage measurements did sound odd, worth a shot.

Blackcorvette_85

ok update.time, it almost started! I went and exchanged the new battery I just bought for the big boy 1k cranking amps, because it just didnt feel like I was getting enough power and started clicking way to easy. So I put that in and turned it over and still was loosing voltage at the coil when I turned it over. So I ran a wire from the battery to the coil and it kept the voltage up and I saw spark on my tester and it sputtered a bit like it wanted to start. I pulled the wire back off and tried it again, went back to no voltage for a few seconds, then jumped up to 10vs while cranking and really sputtered, so close to starting. Thats when I noticed the smoke coming up from the passenger side and the smell of cooking electronics. went and investigated and there was smoke coming out of the starter solenoid. So as far as I know, the starter and the solenoid are grounded by the block right there, so it must be a short in my solenoid thats been causing me all my problems. I wasnt cranking it super long either, where it would have over heated. So unless someone has an other opinion Im going to order a new starter and solenoid tomorrow and hopefully that will fix my problem. .




(side note) I cleaned up a bunch of the grounds . Couldnt get to the main one though. For some reason, I dont know if its an 85 thing or someone was just an ***, but mine isnt above the oil filter. Its on the back of the engine about midway up. With several extensions and woblies I could get a socket on it and made sure it was tight, but there was noway I could have got it out,cleaned up the surface and put it back in without a lift to get a better angle. It was only the battery ground as well, the other grounds were at another almost unreachable place on the back side of the head, might be able to get to it pulling the windshield wiper motor, but its difficult. From what I could see though they looked clean and shiny, so.... who knows. If it tuens out to be a problem, i may just buy a new cable and run it to the open bolt hole on the block above the oil filter.