IM having a real shitty week my car which is ls/vtec running on pr3 ecu is driving me crazy when i turn it on the thing starts to sputter and hesitates to rev then it throws a check engine light and then it says MAP sensor and ECT and IAT but all those sensors are ok the connections were checked about 7 times and they are properly connected and so is the map sensor so i decided to check voltages since i bought a new map sensor and still happens in the helms manual it says he connector should have APROXIMATELY 5.0 volts and the connector has 4.8 is this ok?i need help asap with this thing im going crazy it is OBD1 by the way and this hasnt happened b4 any inputs will be helpful ...

 

5 volts in the input voltage, what is the output, EXACTLY, it should be around 1 volt at a fully warmed up idle.

On a cold start, I think the ECT and IAT should be about 5 degrees of each other but I dont think its super critical, now for a silly question, is there any way for ANY TWO connectors to get swapped, sometimes there are two connectors that look the same and they will fit on the wrong part.

I wont swear to it but OBDI mostly checks for continuity of the sensor circuits, like broken wires or a bad sensor, yes there is also logic checks too, of course. Reset the codes, do they come back before you start the engine or after you start, immedietly upon start or several seconds after you start, more info please.

 

On the same plug theory your correct but i have the manual and the plugs are in there correct locations im trying to find the out put of the map sensor but i dont know how to do that since i dont have the vaccum guage maybe you can help me on that...

Now on that CEL..if i move my ecu in a manner that the cables are straight,not bent,just laying it on the floor the CEL will spark with the car off..now if i bring it back to its location on the passengers kick panel it will NOT throw a CEL so im leaning its the connection.. but either way with it laying on the floor or in its compartment when i turn the car on it will throw those codes and act like if it had a bad MAP sensor when its brand new..but then i DISCONNECT the sensor and the car remains on but idles very low wanting to turn off if i release gas...so thats why im leaning to the ecu ...

ohh by the way when finished rebuilding this motor it did not have this sputtering problem but was very hard to turn on but then it got easier then it got worse again..

please help me on this if you have any idea of whatever i should check feel free to tell me im all ears

 

Map sensor voltage reading on one of the wires will be around 1 volt DC, use a digital multimeter to test it. Wiggle testing the harness is step number one, you have a problem there, maybe a bad ground.

Look at the female pins and see if you can tell if any of them are opened too far, look for corrosion, blue or green stuff in there, open up the computer, it may be full of mold and water.

 

can you explain how to check the voltage more espicificaly?

opened the ecu and its all good.. this is driving me crazy

 

by the way do u think and can it be possible a vaccum leak? where should i look? because i installed a new blox competition series intake mani ..plz help