just finished installing my cc503 cam but I'm running into some issues. car won't hold an idle, keeps throwing DTC code 33 (high map voltage, low vacuum), and will barely increase rpm if at all with any amount of throttle.

just wondering if anyone had any ideas what it could be, I made sure the valve lash was perfect as well, redid it twice with zero changes

 

Might have to try a new map sensor. What's it reading when it tries to idle? Should be about 1/3 of the BAR which is around 30 at sea level.

Is it popping or backfiring at all? Did you make sure to line the timing chain up right?

Check all your wiring and connections again.

 

yes it was popping and backfiring under any amount of throttle

by lining up the timing chain I assume you mean the timing set in general?

 

Making sure the sprockets were dot to dot and all that jazz. Did you use shoebox's guide? It's very comprehensive.

Recheck all your plug wires. That was my problem, but you have to fix that code first. It can be thrown with some cams, but the 503 isn't that big. Check all your vacuum lines as well as the EVAP.

 

Its common for the connectors for the MAP sensor to dry out and crumble, might be worth a shot to check that out too.

 

I just put heads and a 503 in my Z and it did the same thing. No throttle response and backfiring when I tried to crack the throttle. Got a new program from PCMforless and it runs like a champ.

 

turns out cam itself wasn't installed 100%, fixed it today and runs like a champ

 

What was the actual problem?

 

The old 'off 1 tooth' I'm betting....

 

didn't line the dots on the sprockets up completely, I trusted my friend to reinstall the cam itself

 

just gotta redo the valve lash, a rocker or two seem kinda loose.

 

Yeah, the MAP code was a result of the problem, not the cause.

 

oh yeah thanks for the help shoebox, site was very helpful