LT1 starter problem - help.....

[Samckitt]

I have been trying to startup the LT1 in the Monte, hasn't ran for a few years. When I turn the key over to engage the starter, it just chatters. Like the solenoid is engaging & disengaging rapidly & doesn't turn over the motor. Any idea why, what should I do? Can I take off the solenoid & clean the contacts?

[69LT1Nova]

Well, that sucks.

Only time my LT1 did that was when the battery was dead...

I assume you have checked the obvious (fully charged battery, clean and clear contact on the battery wires, grounding is good between engine to chassis and battery to chassis)?

[Samckitt]

battery fully charged, 1/0 cable from battery to starter, & from battery to frame. I will double check cable from block to frame.

[paul67]

If battery is in the trunk i run a ground 1 from engine to battery as well.

[Samckitt]

I couldn't find the wire I thought I had between the frame & block. So I made a new one & put it on. Still does the same thing only not as bad, now it turns the motor & chatters at the same time. Then at times it just clicks, so I take a wrench & rotate the crank a little & then it will go. The motor is around 11.0:1 compression.

battery is in the trunk. Even though I am basically using the frame as a wire from the battery to the block, you think I still need a wire from the battery to the block?

And FYI I did get it running a couple of times. Doesn't idle very good, but give it a little gas & it sounds good. Cam is a CC306 so I imagine I need to have the computer reprogrammed.

[69LT1Nova]

Yep, you'll need to run a wire from the battery up to the block. I was assuming you had the battery up front. If you are running over 9.5:1 compression on just about any SBC, you need direct grounding to the battery to get enough juice to the starter (there is too much loss through the body).

I'm suprised you didn't reprogram you're computer... check out PCMforless.com - they know the LT1 brain inside and out. Yeah, you're car will run, but you'll get every HP out of a good tune.

[Samckitt]

I have a 1/0 from the battery to the starter, & a 1/0 from the battery to the frame, & the same from the frame to the block. Then for kicks I added a #4 (that was all I had) from the battery to the block. No difference, still the same.

[barno68]

I know you said your battery is fully charged, but did you load test it? If it has been sitting that long, or the battery is old it is very possible that it is not holding voltage when loaded. If you do not have a load tester (HF has them cheap), any autoparts store could do it for you.

Brent

[Samckitt]

No I didn't load test it. It is basically brand new, I got it from Autozone, it is a red top optima. I have one in the truck too, & I put jumper cables from it to the one in the car & had the truck running. I might try switching them. Or take it back to AZ & have them test it.

[barno68]

If it tests fine, the rest has been covered... can only be either a weak ground or bad connectivity on your power cable.

[Samckitt]

Almost 100% sure I figured out what the problem is. The starter solenoid. I had suspected that all along. So I took the starter off, & "hot" wired it to a battery, nothing. I took the solenoid off & "hot" wired it, again nothing. I beat on it a little, still nothing. I can't get it to work at all now. Doesn't explain why it worked part of the time while in the car. The motor on the starter turns fine.

[69LT1Nova]

Good to hear you have a solution - let us know if replacing it fixes your problem. It might come in handy for future reference...

[Samckitt]

OK dumb question now. Big red wire from battery goes to big post on solenoid, little purple wire goes to little post on solenoid. So far so good.

Question:
When key in start position, +12v goes through the purple wire to the solenoid to energize the magnet to pull the gear out & make contacts through to starter motor?

If that is the case, new solenoid doesn't work.

[Samckitt]

I just took the solenoid off of the starter & it is hotter than h#ll! The only thing connected to it is ground & hot wire on big post. WTF?

[Samckitt]

The new solenoid won't pull in unless I push it down a little bit. Man this thing is ticking me off.

[Samckitt]

Evidently something is wrong with the solenoid, or they gave me the wrong one. It ill not pull in when I put the battery on it, but if I leave the battery connected & push the plunger in just a "tad", it will pull in the rest of the way. So now I have to take the freaking thing back for them to look at it.

[Samckitt]

Well I took the starter & solenoid back to the rebuild place today & I don;t know what he did differently, but he put it together & it works fine. So I put it back on tonight & it cranks beautifully. Even without the ground from the battery to the block. I have just ground from battery to frame & from frame to block.