Hey guys, I swapped the 4.3 from my 99 Blazer into a Jeep and broke my original distributor in the process. I replaced it with an aftermarket unit and even though it seemed to be set right, I got a P1345 code. I had a mechanic check the cam retard and we tried time and time again to get it set right but couldn't make it happen. I swapped that unit for another new one, timing marks lined up perfect, tab on the rotor lined up way better with the mark on the dist. housing with this one but still got the P1345 immediately on startup. Any ideas on what could be causing this? The engine did sit for about 3 years before starting it last March.
I can't remember what it was with the old dist. and I haven't had a chance to check it since putting in the new dist. But as soon as I do I'll update. I think it was a few degrees advanced but not sure.
The spec for cam retard is +/- 2 degrees. The timing for spark advance is controlled by the computer but the cam and crank need to be synchronized. If your off by a few dgrees the you can modify the hold down and zero it out but you should not get a code. If your off by tens of degrees then you may be off by a tooth and trying one tooth either way may fix the problem. A new distr can also have the gear 180 out and it may need to be moved over. To double check you can drill a hole in an old distr cap and watch the spark alignment while the truck is running.
Do any of you guys know the PID formula for CMP retard? I'm trying to program it into my UltraGauge MX. I've got the header and the code entered but it's not displaying the data. I'm thinking there must be a formula I need to put in?
Nope. They have been trying to do that in Torque Pro for years. Never seen it to work. If you want the supposed formula, go on the Torque Pro Forum. I tried it in Torque Pro - didn't work.
for a 1999 get Car Diagnostic Pro if you have an Android. Dash Command if you have I-phone and opt for enhanced PIDs from within the software.
I reinstalled the new dist. this evening, following this guide to a T. How To Set Vortec Distributor Everything lined up exactly the way it's shown but when I fired up the engine, it ran like crap and 1345 was set immediately. So I tried it again with the old dist. and got the exact same result. I turned it back (counter-clockwise) one tooth and tried again, this time the code did not come back and it ran better but still stumbles badly under heavy throttle. What are the chances that the gear is 180 out on both distributors? Maybe 1/2 tooth off isn't enough to set 1345 but its making the spark gap too long?
I reinstalled the new dist. this evening, following this guide to a T. How To Set Vortec Distributor Everything lined up exactly the way it's shown but when I fired up the engine, it ran like crap and 1345 was set immediately. So I tried it again with the old dist. and got the exact same result. I turned it back (counter-clockwise) one tooth and tried again, this time the code did not come back and it ran better but still stumbles badly under heavy throttle. What are the chances that the gear is 180 out on both distributors? Maybe 1/2 tooth off isn't enough to set 1345 but its making the spark gap too long?
I think it is certainly possible. 360/13/2=13.8 degrees. You need to read cam sensor retard to tell.
05-14-2021, 10:07 PM
P1345 Help?
