New distributor and now dtc's but runs fine.

[96Chevy5.7]

I just replaced my stock distributor with an unknown brand billet aluminum one. Truck seems to be fixed except that it now has 3 codes p0102 (maf) p0300 (random misfire) and p1345 (something to do with the cam I think) If anyone could shead some light on this I would really appreciate it.
Thanks
Jake

 

[Blind]

you need someone with a scanner that can read the cam timing retard in real time to set your timing so that it's at, or near 0.

p0300 is usually a vacuum leak causing misfires on multiple cylinders.

p0102 your MAF may be dirty, but more likely the cable is unplugged/blown fuse/there's a break in the wiring for it somewhere.

 

[96Chevy5.7]

Thanks alot I'm going to get the timing checked soon, any ideas where the vacuum leak would be?

 

[Blind]

Thanks alot I'm going to get the timing checked soon, any ideas where the vacuum leak would be?

it could be anywhere from after the MAF to the intake manifold gaskets, best way to find a vacuum leak is with a smoke machine or carb cleaner sprayed on every hose connection and gasket surface.

 

[96Chevy5.7]

Thanks again I'll check that out

 

[JD4440]

it could be anywhere from after the MAF to the intake manifold gaskets, best way to find a vacuum leak is with a smoke machine or carb cleaner sprayed on every hose connection and gasket surface.

Manifold gaskets can cause a P0102 ??

 

[Blind]

Manifold gaskets can cause a P0102 ??

p0102 could be caused by a vacuum leak, which air getting in past a bad intake manifold gasket would be. But a clogged up exhaust from a bad cat can also cause a p0102.

 

[JD4440]

I have new cats. odd thing is my codes are gone now. when the p0102 was set, you could erase the code and when it came back the engine would stumble/choke down then immediately come back.

 

[VorTecxas]

The P0300 is probably associated with the P1345

P0300 is just a random misfire, which could be caused by the truck being out of time, which is what the P1345 means (crank/cam sensor correlation, which controls your timing). Try reinstalling the distributor, and make sure everything lines up properly. Did you just turn your crank to 0 and set the new one "close" to where the old one was? These trucks are sensitive on the timing, the distributor needs to be set correctly, there are markings inside that need to line up when it is fully seated. If you pull the cap you will see two small numbers stamped on the inside rim of the casting, a 6 and an 8. The rotor tip should point to the 8 with the #1 at TDC on the ignition stroke. I spent 20 damn minutes getting mine right in the Yuke yesterday haha. Since your truck will run, you're obviously not 180 out. Best way to tell (without pulling your valve cover) where TDC is on 1 is to pull your cap and turn your crank to 0. If the rotor tip is close to your #1 wire, you're good, pull the dist and reset it. If it's close to #6, turn the crank one revolution back around to 0. If you're careful to pull the distributor up slowly and adjust it one tooth at a time, you can rotate the oil pump shaft with it, it may take a couple revolutions, but it's better than guessing where to turn the oil shaft to get it to align with #1.

 

[Aloicious]

I'm just going to put this here: http://www.gmtruckcentral.com/articles/distributor.html

you will never get it 100% within spec by trial and error, it may run fine but to get it within the +-2* it requires a scanner that can read the CMPRET cam/crank offset retard. it's extremely sensitive and can even be thrown out of spec by tightening down the distributor hold down. just getting it to where it's not throwing the code isn't necessarily within spec either, I've had the CMPRET be -42* without the code before.

P0102 is a MAF circuit low input, are you sure it's plugged in all the way?

P0300 could be any number of things, get the timing set correctly first and see if that helps.