So I just got my engine all back together today, repaired all gaskets from the lower intake up and replaced the MAP and coolant sensors. I got it all ready and it started up but its running at about 500 rpm and I got the MAP sensor code (33) again. I'm fairly confident the timing is off and I'm getting a pretty uneven idle. Can anyone help me out with what to do here? Im going to go double check all the vacuum lines now...

Set the timing?

would off-timing set off the map sensor code?

It would make it run for crap. If you haven't set the timing, you really need to do that before you go looking at other troubles.

[quote}Code 33 - MAP High

Trouble Code 33 indicates that the Manifold Absolute Pressure (MAP) sensor is reporting an abnormally high voltage. This indicates low vacuum

The MAP sensor responds to changes in manifold pressure (vacuum). The MAP signal voltage will vary from 1-1.5 volts at closed throttle idle to about 4-4.5 volts at WOT. If the MAP sensor fails, the ECM will substitute a fixed MAP value and use the TPS to control fuel delivery.

The conditions for setting this code are:

MAP signal voltage high
TPS is less than 2%
Condition persists for 5 or more seconds
Typical causes for this code include:
Faulty MAP ensor
Faulty MAP-to-ECM connection
Exceedingly noisy spark plug wires
Poor routing of MAP harness (i.e. near coil packs)
Misadjusted TPS sensor
Very low vaccum (check for hose/intake restriction)
Defective ECM
[/quote]

Have you checked what the voltage is on the MAP sensor?

[This message has been edited by phonedawgz (edited 03-19-2010).]

There is not much to the MAP circuit. Make sure you disconnect the battery to erase any previously stored code. Check the 3 vacuum connections: MAP - Intake - Fuel Pressure Regulator - plus the plastic tube that connects them together.

If the vacuum side checks good then that leaves the electrical side. Check the green MAP connector pins and wires for anything broken or burnt.

Do you have the tools to probe the MAP wires for proper voltage?

no havent checked anything electrical, I dont have anything to do such...

[This message has been edited by hinesb1890 (edited 03-19-2010).]

Ok, it's running at 500 rpm and you are getting a code 33? We can work with that. First, disconnect the battery to erase the stored code 33. Then recheck the vacuum connections. Remember it goes MAP - upper intake manifold - fuel pressure regulator. The upper intake manifold is the vacuum source. The MAP and FPR are the vacuum users. Is the upper intake manifold port clogged? How about the little plastic line that connects the MAP and FPR? Is it split or crushed or melted? Try to blow through it. Is it clogged? How about the rubber connectors to the MAP and FPR? Are they split?