I installed a new dist. in my 2000 ZR2. I followed the directions on this site on how to do it. Got TDC, compression stroke, lined up mark on the balancer, put rotor pointing 6 and buttoned it down. It fired right up but it has a miss. Being i am 70 with failing eye sight could i have it a tooth off at the dist? Thanks for your help

 

The camshaft position sensor is most likely off. Either bring it to a shop or if you know someone with a high end scanner they can do it. Camshaft position needs to be at zero +/- 2. This lines up the rotor with the cap electrodes preventing a crossfire which may be the skip. Also make sure you use only ac Delco cap and rotor. These trucks are fussy. And last the hole on the distributor hold down may need to modified to get the adjustment needed

 

If you are off a tooth, then a P1345 code will have set. You did remember to plug in the cam sensor after installing the distributor? Still should not miss, though.


As Newguy states, cam sensor retard should be checked and adjusted if necessary to 0° ± 2°.


If you are interested in doing this yourself, an Android phone, $23 OBD2 adapter, and $8.95 software will read the codes and check the cam sensor retard. $20 software + the rest will do the same and get you a much nicer user interface.


Good luck and best wishes for a successful repair!

 

Thanks guys, as i stated this is a new dist with all new parts, would it not come with the cam sensor dialed in? Can i enlarge the dist hold down and get adjustment this way.

 

Even if everything lines up perfectly there is still a large chance that the cam retard is off. As stated above the only way to get it dead on is to have a scanner capable of reading cam retard in real time. You will likely need to enlarge the hole as you stated but without being able to read the cam sensor output you will have a long frustrating road ahead of you trying to dial it in sadly. It doesn't take much to get it in spec.

 

i just put a new dist. in my truck, it was off -18 degrees. Neighbor had a snap on scanner. best i could get was -12. I have read that a small block chevy hold down clamp will work. You dont have to completely remove your distributor. take the hold down bolt out. while holding the dist in place use a long screwdriver to pop the hold down clamp off..

 

Since distributor is driven off the camshaft and contains the camshaft sensor, even with a new distributor you still have an old set of timing gears and chain between the crank sensor and the cam sensor - which is the relationship you are setting. That and manufacturing tolerances stacking up is the reason cam sensor retard can be off quite a bit. With a used distributor you can have wear on the cam gear and extra up/down play in the shaft to worry about as well. Wear in the distributor gear and stretch/wear in timing chain/gears is the reason cam sensor retard settings are typically off in the negative direction. This does not affect timing as that is triggered directly off the crank sensor by the PCM, but it does change where the rotor is pointing. If the rotor is not pointing exactly at the right spot on the right terminal inside the cap when the spark comes through, you can get misfires. In normal operation the cam sensor only tells the PCM which cylinder is firing at that instant, for purposes of sequential fuel injection timing and misfire detection. Your engine will still run if you unplug the cam sensor entirely, it just wont be able to detect misfires and the sequential fuel injection will default to pulsing 2 banks of fuel injectors. But this relationship of the cam sensor to the crank sensor can be used to orient the rotor position inside the distributor perfectly. This is when the cam sensor retard is reading 0° ± 2°.

Yes, you can elongate the bolt hole in the distributor hold down with (for example) a Dremel tool or some other sort of grinder. That will get you enough adjustment. Or just replace the clamp with a small block Chevy V-8 distributor hold down. either way works.

DO NOT do this unless you have a way of reading Cam Sensor Retard, and know that doesn't happen with most cheap scanners. Only two inexpensive ones I know of are Android apps - Car Gauge Pro (1998+ Blazer) = $8.95, and Dash Command with Extended GM PIDs add-on (1996+ Blazer) = $10 + $10. Both require a separate Android phone or Tablet and a Bluetooth OBD2 adapter. I highly recommend the BAFX Bluetooth OBD2 adapter from Amazon ($23) as the refresh rates with others can be dismal.

 

Thanks for the help. I do have have an Android but if i bought the equip i need to check i would not know how to set the cam sensor. I may just go to a shop and let someone do it. Thanks again