Truck cranks but will not start [Solved].

I did check the resistance on the new crank sensor before installing and it read 2220 ohms which should be good.

 

Well you could test the circuit with an ohm meter, check between E6 Pin 20 (White) and E6 Pin 21 (Black) and see if the resistance is the same as the spec for the crank sensor which is 1850-2450 ohms
Also check between Pin 21 and ground, you should see an open circuit.

 

I was thinking the same thing. Checking pins 20 and 21 would tell me if the connector is 100% engaged to the Crank sensor or not.

Having an open circuit would mean a break somewhere in the wire?

Another issue discussed here was maybe the sensor isn't 100% seated inside the housing leaving a gap where it is inserted inside the engine.

 

Yes the test's I posted above will tell us whether or not the circuit is intact and if it's shorted to ground or not.
If those test's are good then the next step is gona be scan tool and see if we have an RPM signal.

 

Perfect, sounds like a plan. Thanks again, ill tell you what I find tomorrow.

 

Hang in there, we'll get it going

 

After last night, I'm pretty confident we'll get her back to running. Check engine light is back, power to the ECM is back, power to the EFI 10a fuse, and hearing the fuel pump made me see the light at the end of the tunnel. Lol

 

There is a very slim chance that the tach signal isn’t making it to the tachometer in the dash.
But that is highly unlikely, since the truck doesn’t start. The ECU provides the tach signal to the tach.
So, it is likely the crank sensor, or the crank sensor circuit.

What I’m saying is “technically, yes” the tach can not work, with a good crank sensor/signal. Again, in your situation, this isn’t likely.

 

Okay, there seems to be an open circuit with my crank sensor.

My new sensor before installation read 2.20 on the 20k setting so that should be 2200 ohms

Pins 21 and 20 reads 2.12 on the 20k setting so that should be 2120 ohms

Pin 21 to the ground does infinite 18.35 on the 20k setting so that should be 18350 and OL at 20k

 

Accounting for resistance changes due to temeperature it looks like a good reading and it's not shorted to ground so at this point the circuit looks good.
Next step scan for codes and see if we have an RPM reading.

 

The scanner should be in the mail within the next he or so.

Ahhh, so if it read zero ohms on 21 to ground that would mean an open Circuit?

 

0 ohms would be a short or complete circuit.

A complete open would be OL on the highest ohms scale (typically 2M to 20M depending on the meter).

Remember resistance is the measure of how hard it is for power to get from point A to point B, the lower the resistance the more current can flow.

OHM's law: Volts/Resistance=Current in Amps

So a circuit with say 1 Ohm of resistance can carry a maximum of 12 Amps at 12 Volts.
A circuit at 10 Ohms of resistance can carry maximum of 1.2 Amps at 12 Volts.

There are variables to this such as corrosion in a circuit can give a low resistance value but when current is applied resistance increases, this is known as Voltage Drop.

 

I got the scanner and I'm using TORQUE PRO. It found 10 faults. It has real-time data with RPMs, do I crank it over while using that feature?

 

First clear all the codes, alot of them were probably set from all our fiddling then yes watch RPM while cranking.

 

Okay, how long should I crank it for?

 

5-10 secs should be enough to see if you have an RPM reading.

 

2 faults now and RPM maxed at 190 RPM

 

So we have RPM, did you plug the APP and throttle body back in?

 

Damn, forgot about the throttle body. It's connected and NO codes now. Still does not start......

 

The emissions monitors aren't useful to look at, they are mainly there for inspection places to determine if they have all ran before passing the vehicle for inspection in areas with emissions testing.

Well let's revisit things do we have spark and fuel?