View Full Version : MAF cause engine to not start?
Will my missing MAF sensor cause ls2 to not start? I have good grounds, fuel pump cycles, throttle moves with the pedal. I have no spark at the plugs.
Should the MIL light light up when the key is put to ignition for a sec or two ?
2ABodies1FBody
08-29-2015, 10:32 AM
Typically, the engine will start and idle without the MAF Sensor, but will stumble when the throttle is opened. Of you have no spark, I'd look at the cam or crank sensors first. If the ECM doesn't have a cam position signal it won't fire the coils. The MIL should come on when the key is turned on for bulb check.
andrewb70
08-29-2015, 03:43 PM
Also make sure that the ECU is getting power from a source that is hot during cranking.
Andrew
Thanks, how can I tell if I'm getting a cam and crank signal? Can I check voltage somewhere?
2ABodies1FBody
09-01-2015, 01:40 PM
When I worked at the dealership, we just plugged in the scan tool, and looked to see if there was an rpm signal when cranking. Do you have access to a scan tool?
Clint
I can probably get one. Looking at it deeper it looks like when I was trying to get oil pressure in the motor I didn't have enough grounds hooked up and the starter used the harness main ground through the computer. My main ground wire at the computer (bk-red wire) looks like it got hot. Hoping I didn't fry the ECU! Anyway to check?
andrewb70
09-01-2015, 04:30 PM
I can probably get one. Looking at it deeper it looks like when I was trying to get oil pressure in the motor I didn't have enough grounds hooked up and the starter used the harness main ground through the computer. My main ground wire at the computer (bk-red wire) looks like it got hot. Hoping I didn't fry the ECU! Anyway to check?
Again, scanner. If it commucates with the ECU, then it's not fried.
Didn't get a scanner yet but, I checked and I am getting a crank signal back to the ECM. It is ranging ~8-9 volts. Only weird thing that is occurring now is the fuel pump is running constantly. I am getting ~6.5 volts from the ECM to the fuel pump relay? The other day when I was messing with it I was getting a MIL light, now nothing.
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