Just got a new project car/toy to replace the V6 car. My first LT1, got a sweet deal on it so I dont mind rebuilding if it I end up having to. Car is in great shape otherwise. Previous owners had no idea what was wrong with it. Drove fine one day, came out the next and slow crank, no start.

Pulling plugs makes pretty much no difference in cranking speed. I got it home late last night so didnt get to play/diagnose much, just looking for opinions. I put a good fully charged battery in and it cranks slow like it would if the battery was fixin to give up and start clicking the solenoid. Headlights dim a good amount while cranking, so Im thinking the cables to the starter are ok. Is it possible the starter is just pretty much shot and dragging? would it make a noticeable difference in cranking speed plugs in/out if the starter was just burned up?

Looking at bearings maybe? Oil looks good, full, almost new. Did notice fuel smell and heard the wires sparking so I know thats good at least. No codes, cars been sitting for a while with no battery in it.

Bad ignition switch possibly? I know usually they either work, work intermittently while trying to crank or nothing, but could it make it crank slowly? Maybe not letting enough voltage to the solenoid? Could it possibly be the solenoid not passing enough current to the starter motor itself?

 

Sounds more like you have a bad connection since the lights dim. But to rule out the starter, jump both ground and pos with jumper cables directly to the starter. Be sure the battery you have in there is over 550 CCA when you do it. If the starter still drags when jumped directly, rotate the engine around by hand with a breaker bar. If it feels too hard to rotate by hand, pull the intake and prime the oil pump by hand. Watch for oil coming up the push rod passages. If it doesn't you know the problem.

 

I was planning to turn by hand later today when I go home, see how it feels that way. If it turns "normal" by hand I'll just yank the starter off, test it/rebuild it. Like I said this is my first LT1, so should it be any harder to hand crank than a regular SBC? I would think not, especially since the plugs are out. Battery I believe is a 750, I pulled it from my V6 car that was my daily driver up until I brought the Z home last night, its about 2 months old. Spins the 3.4L over like it has a high torque starter so I know its good. If it turns over good by hand, I will also replace the battery cables when I do the starter. I built my own out of 2ga. wires for the V6 car and left them a little long so I could use them on a Z. I had already planned on replacing the car with a Z28 when I had to put them on that car. Have all my battery cables, starter, power dist block, alt, and ground upgraded to 2ga wire on the V6, so I'll be putting it all on the Z anyway. I know the first post made me sound like a newb, just wanted opinions before I got to play with the car, Have searched and seen several posts where it was cables, starter, switch, a melted wire above the starter, stuff like that. Hopefully I'll get some underhood time later today in the DAYLIGHT lol, and can get somethin figured out. If its not the starter and wont spin by wrench very easy then its coming out for a rebuild, maybe cam, headers, head work, etc.

 

Well its been raining and storming too much to crawl under the car to hand crank it. I did fail to mention the car has a non functioning aftermarket alarm. I wasnt sure if it was still there, all I had seen was the siren and a switch. After poking around some and between the pouring down rain, I found the box and a mess of wires. From what I can tell by the fcc numbers, its a Freedom 300atv alarm. Theres a toggle switch on the console with one wire broke off/missing. A valet switch that doesnt click or press, and probably half the wires are either ripped apart or have never been stipped back and used. Im pretty sure the alarm wasnt in daily use when the car quit starting, but is it possible this thing, with what is still hooked into the car, is not letting enough current through the ignition wire or something causing the slow cranking? Or is it most likely just there and has nothing to do with the current problem? I do plan on ripping it out and connecting everything back where its supposed to be, IF it'll ever quit raining. Have a truck in my garage with a shelled trans right now so the toy isnt as accessable as Id like.

Also-- the locks arent working, part of whats making me think this old alarm is causing some trouble. Is it possible, or would it just not crank at all if its messing with it?

 

Never experienced an alarm reducing current. Only seen them on or off. You mentioned that the starter turns over slowly and the lights dim. I wouldn't think the alarm would do any of that. With the exception of it possibly drawing current all the time and running the battery down. But you should have eliminated a discharged battery as cause long ago. Easy to do.

 

I just brought the car home saturday, and between a one year old and rain, I havnt got to do much. I figured the alarm would either not interfere or cause a no crank period. Just wanted to be sure it couldnt affect the current flow somehow with the starter interrupt. The battery is out of my DD V6 car, I gets swapped back in the running car when I get done playin with this one, its also on the charger right now to make sure its all the way up.

They also had the fan relay grounded out to where they came on with the key...... I unhooked that today and pulled around on some of the alarm wiring under the dash. Threw my battery back in to check a few things, lights, rear defrost, etc. Just seein what else worked and what didnt. Decided to hit the starter and see how it acted again.... Cranked over 5 times faster than it has since I brought the car home. I know the fans draw a lot of current, but that also makes me think the whole problem is electrical and hopefully not bearing related.

Im going to try to get time to put the plugs back in tomorrow and see what she does. I've seen a few LT1s that do seem to crank kinda slow but start every time. Dont know how it'll crank with plugs back in, but if it doesnt slow down much, Im pretty sure it'll start. It is getting fuel and you can hear the plug wires tick where they are layin close enough to ground in the engine bay.

Do LT1s usually crank a little slower than say a regular 350 in a pickup or a TBI caprice or something like that? I see a lot of posts where people put high torque starters on their lt1s to speed them up, but is it because of this or because they want it to whine while its cranking (not being serious).

 

Put the plugs back in last night, now it'll spin a few times and slow way down like the battery is dieing. I didnt push it any farther to make it click or anything. Still havnt had a chance to crawl under the car to hand crank it, So thats where Im sittin right now. Going to try to get some help and push the truck outta the garage and get the Z28 in there where its dry and I can get under it. It does pull the volt gauge way down when you crank on it, so am I still lookin at electrical or would it pull the voltage down that hard with bad bearings loading up the starter? I did look in the oil cap hole and its pretty wet in there, fresh oil, car sat for about 6 months or longer before I got ahold of it, so Im pretty sure thats from me cranking on it. I'll probably pull a valve cover and the plugs back out and get somebody to crank on it and watch for oil. Dont really wanna pop the intake off yet if I dont have to.

If its pumpin oil into the heads/up the push rods, bearings should be fine right? or at least not tore up/seizing? Wish the weather would cooperate so I could just change battery cables and get under the car, check voltage, pull starter etc.

 

First off, I only put 6 of the plugs back in,and are only finger tight right now, didnt have much time and number 2 and 7 were pain the a$$ to get to from up top for me. Grounds still soaked, still raining off and on. Threw the battery back in the v6 and let it charge up. Cranked just fine in the 6. Let it run while I decided to cut the rubber off the end of the side post connectors on the Z. Sure enough, major corrosion inside, outside that you could see wasnt bad but not good. cut all the rubber off and cleaned up the terminal ends and bolts. I then decided to put the battery back in to see if I picked up an voltage on the battery bolts, got a better spark (door was open, so dome lights came on) so I decided to see if it would crank again. She fired right up and ran on 6 finger tight plugs.

First thing I looked for was oil pressure, cause the shop I bought the car from had diagnosed it as being locked up/ bad bearings...... Cant wait to call him up and let him know that he pulled all the plugs and spent days trying to get it to crank and pour oil down the cylinders, etc, and it was battery cables. Anyway, oil pressure steadily rose up to about 80 within about 20 seconds, then dropped all the way back down. I shut the car down and sure enough all my oil(well most) is under the car now. Couldnt get the car jacked up very good because of my mud/gravel driveway, but the filter is wet and was dripping still when I got far enough under to see it. Couldnt tell if the cooler was still on it or not. Felt around the back of the intake and oil PSI unit, felt 99% dry. So is there anything else back around there that'll dump that much oil that quick besides filter or cooler? Im going to round up some help later today and get the truck out of the garage and get the Z pushed up in there so I can check into the oil leak and replace the battery cables, get the plugs tightened up and the other two in.


For running on 6 finger tight plugs, she sounded good from what I could hear with the two cylinders open. Compression sounded pretty good on those two lol.