Divine

95 Camaro Z28. What should the MAP voltage be key on engine off? I'm getting 4.58 volts. Seems a little high don't it? It's not setting a code. Car won't start because it's flooding out.

Divine

Anybody?

Old Geezer

iTrader: (3)

Check the connector. They are known to get brittle and break....
Here's a t/s schedule.
1. Inspect the rubber nipple (fitting) from the MAP sensor to the throttle body. Repair as necessary. CAUTION: When testing the MAP sensor, be sure that the harness wires are not damaged by the test meter probes.
2. Test the MAP sensor output voltage at the MAP sensor connector terminal B. With the ignition switch ON, and the engine OFF. Output voltage should be 4 to 5 volts.
3. Test the MAP sensor output voltage at the MAP sensor connector terminal B at a hot, neutral idle speed condition. The voltage should drop to 1.5 to 2.1 volts.
4. Test MAP sensor supply voltage at sensor connector terminal C with the ignition ON. The voltage should be approximately 5 volts (�O.5 V).
Also, check the fuel pressure regulator vac hose. It should be dry. If there's fuel in it, the diapram is ruptured, and is flooding the engine w/ fuel.
W/out a code set, the map volts are not out of range. [either hi or low].

Another source for flooding could be the eng temp sensor..Shows -40*, and floods the engine w/ fuel.

Divine

Temp sensor checked out good. MAP is reading 4.5 volts key on engine off. The came is much larger than stock and I wonder how much vacuum it's actually pulling. I'm going to try pulling vacuum with a hand pump to lower the voltage at the MAP and then see if that helps. And I will definately be checking the regulator.

johnson73801

iTrader: (3)

i know that you said it seems to be flooding but is your opti sparkin the wires??

Divine

Yea. I did a lot of diagnosing this weekend. Changed plugs saturday morning and it runs now but it's still flooding on the #2 cylinder. I've checked the plug wires again and swapped plugs and it looks like I need to test the injector. May be stuck open. I'm trying to find an injector shop in Southern Indiana.

johnson73801

iTrader: (3)

if you think that the injector is stuck just raise the rail so that the injectors are out of the holes and turn on the key and see if its dumping fuel.

jimmyblue

iTrader: (11)

That's about normal. Engine not running, full atmospheric
pressure, full scale reading. If it comes down to about
1.5-2V at idle then it's all right.

MontecarloDrag

iTrader: (3)

The MAP should read a pressure if about 85 KPa.
Find the part number of the MAP, then download datasheet. It has a formula to know exactly how much volts it should read for a given barometric pressure.

Divine

Found out the MAP was good. We changed plugs and it runs now but #2 is overfueling. Plug wire is good. Both #2 plugs we have pulled out haven't looked good at all. Trying a different injector now.

LT1DG

That's weird the other day while warming up I look at my scanner and my temp shows - 40 every 2 sec. What's that mean?