HI, I'm new here. Im pulling my hair out with my 2000 4x4. I had the motor rebuilt from top to bottom because I fully blew the head gasket, oil and water fully mixed. Outside of the motor I've replaced the maf sensor, crankshaft sensor, coolant temp sensor, ignition module, distributor cap and button, plugs, wires, belt, and recently the starter after it didnt want to turn over. I had the "lightly used" starter bench tested and everything worked as it should, although sometimes you can turn the sprocket in the opposite directon briefly. I cannot figure out why it will not turn over. I can hear the starter spinning when trying to crank it. I thought the starter solenoid was bad but the bench test proved me wrong. Also I used a mirror to look at the flywheel and it has no missing teeth from what I can see. Please someone help me figure out what the issue is. I've been going crazy for over 3 weeks now!

 

For the starter motor to run, the solenoid must activate to make electrical contact so the starter motor will run. At the same time the solenoid plunger pushes the fork that pushes the starter gear into the flywheel.

You say it was bench tested and all is ok. The starter drive often called the bendix is a one way clutch. It allows the starter gear to turn the flywheel but when the engine starts it will not allow the engine to drive the starter motor which would overspeed the starter and explode the armature windings. This is why you can rotate the gear on the starter one way but not the other way.

It sounds like your problem is a bad starter drive which is slipping and not allowing the starter to turn the flywheel. They can't bench test this because they have no way to impose the load from the flywheel to the starter drive.

You can buy the starter drive and put it in the starter.

 

I would double check that the timing was set-up correctly after the rebuild. It needs to be set to zero degrees TDC #1 (The computer takes care of the advance and retard). If you use the wrong timing mark on the crank pulley (there are two), you will be firing the wrong cylinder and fighting the starter. (It will seem like the starter lacks the power to turn the engine over).

This happened on a friend’s 2000 Blazer LS in September because a mechanic set-up the distributor to the first timing mark on the crank pulley and instead of the second. There is a great DIY thread on here that helped me fix it for him (about 15 minutes and an 8" flat-bladed screwdriver).

https://blazerforum.com/forum/tech-articles-diy-29/edi-engine-timing-24373/

Check it out and post back. You'll either be running, or we'll be one-step closer to the problem.

Good Luck!

 

Am I reading it right? The starter motor is not engaging the flywheel?
If the solenoid is good then I'd check the "new" starter versus the old and make sure the mounting points are of equal thickness. It almost sounds like the starter may be shimmed out too far or it's the wrong starter, or a faulty starter.

 

Sword: after putting in the new starter it did start, twice, after some cranking and drove great. Would it run if the timing was off?

Oisinirish: the starter came off another 4.3l an '03 or '04 cos the heads I got came from the same motor.

Have any idea where I can get a starter drive?

 

easier to just get another starter,, Trade yours in at an auto parts store and get another one.. let them fuss with it.. thats their job.

 

I used to replace the drives when needed, and any auto store had them. They were not very expensive. However I just looked at Advance & OReilly's sites and they list the solenoid seprate but not the satrter drive (bendix). They are not hard to install but you will have to find one first.

There is a place here that rebuilds starters so I know they would have them.
It is up to you if you want to save a few bucks or shell out over $100.00 for a starter.

Since you said the starter was slightly used it sounded to me like the drive had just gone bad. If it was an old worn out starter just putting a drive in in might not be wise as the solenoid of motor could go out next.

 

Crazy:

The Blazer I worked on did run with the timing off – sometimes. I think that is why the mechanic was chasing the issue as a starter problem. I couldn’t find anything else wrong, so in the course of searching the symptoms I came across the timing issue. I think sometimes he just got lucky on the start and would fire another cylinder (#4?) and once running the computer advance/retard could compensate enough to run – just a guess.

Hope it was just a simple starter problem!

 

sword: I really hope that is not the issue. I wish there was a way to load-test the starter. I think I'm going to pull the starter from my dad's '03 S10 just to see if it is indeed the starter, I don't want to buy something I never needed. The guy that did the job said he's done hundreds of chevy 4.3l jobs, i hope he didnt screw up the timing. I know he did check the chain to see if it's worn, said it's still good and tight. But to do the bottom end I presume the timing chain and such has to be removed. Hoping my dad won't freak, I'll report back on wednesday.

 

I got a low mileage replacement off of ebay and dropped it in, started right up! But now my issue is that half the time it's hard to start, cranks and cranks before firing up. Sometimes if I immediately rev it after starting; the smallest bit of throttle makes it want to stall. hmmm?

I got a low mieleage starter from ebay, dropped it in, started right up! But half the time it takes some cranking to get it started. And also sometimes if I give it any throttle after starting it then it wants to stall.... have to wait a few seconds or a minute before putting it into gear. Whats the deal? I'm still curious if my timing is off from the rebuild and its working against the starter... but I read the computer adjusts the timing accordingly.