Can part of an ecu malfunctin and the rest works?
06-20-08, 04:26 PM
#1
Can part of an ecu malfunctin and the rest works?
I think I have some sort of problem with my start map on map on my ecu. I'm fairly sure the car isnt running the start map, makes the car kind of hard to start. I backprobed pin 3B with a paperclip and ran a wire from the starter cut relay so it would get the 10+ volt signal. The car was starting easy (just cranked it I didn't have to pump the gas while starting like i do now). So i decided to make it permanent and i soldered it into the harness. Well as soon as I got done it tried to start it and it wouldn't start unless i pumped the gas. I also reinstalled my turbo timer, could that have anything to do with it? It is also worth mentioning that i didnt cut the wire going to 3B i just tied into it. Also i checked for voltage at the solder joint and i was getting 10.5 volts.
Any ideas?
Any ideas?
06-20-08, 08:35 PM
#4
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IF the ECU sees the Start signal at 3B, when the key is turned to Start, and your having problems during cold engine starts, then maybe the water thermo sensor isn't plugged up or has a pin pushed back in that plug.
The Start map is used when the rpms are under 500rpm, 3B sees voltage and the water thermosensor is outputting. Acutally if it does not output, I'd bet the Start map is used anyway. But the ECU depends on the water thermo sensor outputing to the ECU during Start to get the right fuel delivery during Start. An open water thermosensor equals a default of 180* which means too little fuel during cold engine starts.
By going to the FSM Fuel and Emissions section, CONTROL UNIT pages, you will see what each pin on the ECU should be outputing with the key to ON and engine running. It takes only about thirty minutes to check the wires/plugs at the ECU and compare what you get to the figures in the CONTROL UNIT pages.
You don't have constant voltage going to 3B ALL the time, do you? Shouldn't.
Hard to start ALL the time or just with a cold engine or just with a hot engine?
The Start map is used when the rpms are under 500rpm, 3B sees voltage and the water thermosensor is outputting. Acutally if it does not output, I'd bet the Start map is used anyway. But the ECU depends on the water thermo sensor outputing to the ECU during Start to get the right fuel delivery during Start. An open water thermosensor equals a default of 180* which means too little fuel during cold engine starts.
By going to the FSM Fuel and Emissions section, CONTROL UNIT pages, you will see what each pin on the ECU should be outputing with the key to ON and engine running. It takes only about thirty minutes to check the wires/plugs at the ECU and compare what you get to the figures in the CONTROL UNIT pages.
You don't have constant voltage going to 3B ALL the time, do you? Shouldn't.
Hard to start ALL the time or just with a cold engine or just with a hot engine?
06-22-08, 03:56 AM
#5
sometimes it starts easy sometimes it starts hard, doesn't really matter too much if it is cold or hot. I'm going to unplug the turbo timer and see if it makes a difference, because the only thing i changed from when it was working fine to when it wasn't was soldering the wire and installing the turbo timer. I just recently put a new thermo sensor in the car.
I only have 10 + volts when cranking
As far as the FSM is concerned, i just about have the ecu pin out memorized.
I only have 10 + volts when cranking
As far as the FSM is concerned, i just about have the ecu pin out memorized.
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