Im racking my brain on this one, and would like some CF input.

Short cliff notes:
Tues nite, driving home- car looses power, wont accel. Pull over and shuts off. Wont start. After 45 mins or so, I get a p0336 crank code. Call Tow man.

Wednse nite- replace crank sensor, inspect wiring as best as possible for melted cracked or broken wires. none. Car still wont start. No codes.

Tonite (Thurs)- Get HPtuners to perform crank relearn. Cant perform due to coolant temp not high enough. Still no codes, no start.



Ok, I have checked a few things and I am getting a p1637 & p1638 codes for Terminal L, but I think that is because the car wont start, maybe not?

I am getting spark, fuel pump is priming, and I have airflow. No start. I can spray a shot of starter fluid in the maf and it will start for a few seconds. I checked and I am not getting injector pulse, but I am getting power to them. (ecu not grounding the circuit) Which leads me back to the crankshaft relearn (maybe obvious)

How do I get the relearn performed if the coolant temp threshold is too low?

What else could be possibly causing a no start no code situation? Car was running beautifully then nothing. (no flashing lights, no check eng light, just the loss of accleration with the pedal)

 

A few items:

1) What is the ECT reading static?

2) I'm concerned that you are receiving alternator circuit codes, and have a possible ECT problem. Both harness are in the same location. Have you inspected them for damage, shorting, etc?

3) With HP tuners, can you read an RPM when cranking? You should read something. If you are getting spark, it suggests the PCM is seeing a crank sensor output.

4) Please check all codes again with the DIC.....NOT HP Tuners.

5) Also, if the PCM does not read a crank sensor output, it will drop out the latching voltage to the fuel pump relay......just another data point.

 

Well then ect was replaced three and half months ago, broke it during a prior repair. The connector on the sensor got broken, connector was unplugged. (edit. connector was unplug when the sensor got broken when removing the header.)

I will recheck the rpm signal when cranking.

 

Ok. If the connector is not plugged in on the ECT, the PCM thinks it's below zero degrees F, because the resistance is infinite.

 

the hptuners is reading rpm signal. The ECT is at 79 degrees.

p1637 h c PCM
p1638 h c PCM
U1064 h Radio & AO-LDCM & A1-RDCM

are the codes when pulled from the DIC


the ect is pluged in

 

So, the ECT is not too low. You are getting an RPM output, and spark, so you know the crank sensor output is getting to the PCM.

 

Yes that's correct. No injector pulse to fire appears to be the issue. I have ohm checked the fuses to make sure none were blown, also switched gin relays incase of failure. Nothing changed. Oil psi sensor is three months old and reads pressure

 

The only issues I'm aware of, that will prevent an injector pulse are:

1) No crank sensor output
2) No 12 volts to injectors
3) Security problem(in correct password from BCM).

 

How would I check the password? I deselected vats in hp tuners to not require it without change too

 

If I'm not mistaken, that only affects the PCM, not the BCM. Is your security light on solid? Are you absolutely sure, no fuel is getting in the cylinders? What is your fuel pressure?

 

No security light. I need to get the fuel psi pressure kit from work and check that. I'm fairly confident no fuel is being injected, no substantial raw fuel stench from exhaust.

 

I'm still not understanding the coolant temp issue, with HP tuners.

 

Neither am I. I see the box that needs clicked to do the relear, but it isn't clickable. It is connected and reading the ECU.

 

I seem to recall the wiring for the injectors can get chaffed on the back of the heads (causing them to not function) -do a search on it, there were pics in some of the threads.

 

interesting, i will search for that info and look into it tonight or tomorrow morning

 

Here is one of the many posts:
http://forums.corvetteforum.com/c5-t...e-harness.html
If the wire is/was chaffed-one/both of the injector fuses may have popped too-check to see what state the fuses are in.

 

All fuses are good, checked multiple times

 

True, but that would only make sense for the 12 volt supply. Each injector is provided a ground from the PCM to pulse, so all 8 wires would have to be damaged.

 

At this point I am still going to look into the possible chaffing. I am even going as far as putting 5 gallons of fuel in even tho it says there is 1/4+ of a tank. [baffeled]

 

.....and your fuel pressure?