Is there a way to test this?? I got a code 44 on my 305 TBI and I think this could be the cause. The car has a tendency to surge when cold/idle also jumps from 500-1500rpm. How much do these run by the way (map)?? OR could it be the ignition control module causing this?? (I've reading up in the archives)

[This message has been edited by fbodfreek (edited February 21, 2001).]

 

To check your MAP sensor, look at the procedure I posted in the TPI forum in response to GTA91 "Code 33 MAP and BAD stumbling!! HELP!". That should do it for you. Seems like they cost about $40, but I don't remember for sure. However, a code 44 indicates a lean condition, which could be a number of things such as a vacuum leak, defective O2 sensor, poor electrical connection and lack of fuel. From your description I would suspect a possible vacuum leak. Spray some carb cleaner around and listen to the idle to see if it changes. If it does, you've found your leak.

 

I've suspected the same (vaccum leak) but have been too lazy to check it. I have a new o2 sensor, so I'm thinking the plan will be to test for vaccum leaks, then the map. Fuel pump/fuel pressure is an issue I don't want to address at the moment (I don't even want to think about having to replace it!!:-)

 

Dude...unhook the MAP sensor, not the vacuum line, but the electrical connector. The computer will realize pretty quickly that there is no map, and then guesses engine vacuum based on readings from O2 and TPS, if the problem goes away you probably have a bad MAP, if there still there start looking else where.

 

How many people out there have actually replaced a BAD MAP sensor? I have never seen one (On a GM product) and was curious if our shop was just lucky, or what!

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Working on:
'84 Z28 LG4 305 with 200,000 original miles!
Added dual elec fans.
145 MPH IROC Speedo
Building 430 HP 350 (ZZ430)
using primarily GMPP parts.
Short block sitting on a stand.

Starting to look like the Kicker poster child!

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