Overfueling like crazy

[Divine02]

95 Camaro Z28. 383 that has had the ECM tuned on a dyno. Car was having problems before we freshened up the motor. Just got the motor back in it and it did start but it's flooding out. The plugs are soaked in fuel. I've never seen a motor over fuel this bad before. Finally got a Snap On Scanner hooked up tonight and the only thing I have seen that is wierd is the desired idle. It is at 3180 rpm. We hooked up a factory ECM back to the car and it is still reading the same thing. What tells the computer that the desired idle should be up so high? I also thought the MAP sensor was bad cause it was reading 4.5 volts but apparently it works backwards from what I thought. Hooked up a known good MAP and it still reads the same thing. All of the test and voltage readings were taken with the key on engine off because the car will not start. It's shooting fuel out of the exhaust and has been backfiring like crazy. Any suggestions?

[95ImpySS]

MAP should be 1.03-1.04 KOEO

Desired idle is that high because its not running. Dunno what thats about. But my car says the same thing KOEO

Try disconnecting the o2s and also check fuel pressure

[Divine02]

Fuel Pressure is good. I'll try disconnecting the o2s. I'm really curious why the MAP voltage is so high with two different sensors. I will also try using a vaccum pump on the sensor to see if the voltage changes. The voltage does go to zero when you unhook the sensor so it's not gaining voltage anywhere else in the harness.

[95ImpySS]

Another thing you can do is measure the resistance from the MAP sensor plug to the plug that goes to the PCM. Just to make sure there are no breaks or wires touching.

Also check your grounds. Has the engine run since it has been installed or has this been an issue since re-installation?

Try disconnecting the fuel pump fuse and crank the motor over watching MAP values.

[Divine02]

It was having over fueling problems before we pulled the engine out and we did have it running a couple of times since we have reinstalled the engine in the car. Checked grounds and I haven't seen any problem there. We can't get it to fire up now.

[grn95t/a]

curious what your maf and inj values are while your cranking? i have a freind that is having the same issue with over fueiling....


http://ltxtech.com/forums/showthread...fire-got-worse.



.....

[Divine02]

I'll try to get some more info tomorrow night. I'm going to use a vacuum pump on the map sensor and see if I can change the voltage and possibly lean it out. i know the cam I put in this engine isn't going to pull much vacuum. I just haven't checked it yet to see what it is.