I don’t see any excessive play in the throttle shaft. I believe my distributor is bad because the timming suddenly changed. And it really only stutters when it’s warmed up..
Is the distributor loose? Can you turn it my hand without loosening the hold down clamp when it is cold?
Try to turn it again when it is hot.
Is the hold down clamp bent or cracked or installed upside down?
The gasket on the distributor is actually a "friction washer" and they are avaiable in different thicknesses.
That is how you set distributer gear lash.
These days, gasket kits and aftermarket distributors come with a really cheap really thin paper dist. gasket.
like .020 thin and that gasket has zero friction material in it.
They are garbage.
The most common problem with stabbing a chevy dist is being off one tooth.
The sneaky little problem on a tbi is when you go through all of the effort to set it at 0 TDC and you check that over and over.
When they have what they assume are downstream performance problems they never go back to see if the dist is moving.
Remember, if the distributor is moving even a couple of degrees the ecm will try to control it. Slowly but surely as the distributor slips.
So the normal instinct because you know for a fact that the dist is at tdc is to get a timing light and look at the balancer marks and try to chase advance and wonder what the hell is going on.
Here is the tricky part about a poorly seated distributor.
If it is loose enough and that friction washer is not doing its job.
During acceleration and decelleration the distributor body can lift out if the bore and spin and then drop itself back into the same bore but just a little off.
If you hit it hard a different way,?
It might just drop back into the same spot that it was before.
You need to pay as much attention to lash on a distributor as you would on the diff.
And is very much the same process.
Paint the gear, bolt it in place, pull the fuel pump fuse, pull the injector pulse fuse.
Crank it
Pull it out and look at the pattern.
Any chunk that snaps off of the distributor gear or the cam gear is hardenned steel and it will break something.
Probably your wallet.
I know, this sounds like a lot of bullshit to go through and it kinda is.
But. This is not a new thing at all.
Even back in the 80s we knew that detroit made factory parts had to be adjusted and shimmed and made correct for your block.
Distributors have never been a bolt in part. That is why the used to sell "corrective friction gaskets"
Starters have never been a bolt in part.
That is why they sell starter shims.
Another left turn for those of you who asked for it.
If you have a starter that is weak but does not grind or screech?
Do not ever ever ever turn in that starter for the 10 buck core.
The starter gear to flywheel dimension is determined by the nose cone on the starter and how it bolts to the block.
If the old nose cone is not cracked, you can buy a new end bushing for it for 4 bucks.
The only thing you need is the 50 buck motor.
Buy the cheap 50 buck starter.
Put your factory nose on it.
Torque it back in place.
Done deal. I might be a dumbass but I havent shimmed a chevy starter in 30 years.
Its the nose cone.
If it works? that is like gold