2G No Start / P0335, P0340, P01113 / EVO 8 ECU

[wing3r09]

Gonna try and make this long story, short...

Car ran last year.

Attempted a start this summer and was getting a stumbling start up to about 1200-1500 rpm, then the car would die.

BLT checked good. Suspected bad fuel. Drained tank and lines, fresh fuel, still no start. Sent injectors out to get cleaned and found they were junk.

Upgraded from 950 low z to 1300 High Impedance. Installed an FIC resistor jumper pigtail to bypass resistor. Updated ROM for injector scaling and latency. Still getting the stumbling start and die.

Found that Omni 4bar MAP was reading around .7bar at KOIO. Changed to GM 4 Bar and is now reading 1.06bar at KOIO.

Realized the DTC light was pulled and that why I wasn't seeing a DTC on the dash. Pulled the codes and I'm getting P0335 (No crank signal reference at ECU), P0340 (No Camshaft signal at ECU), and P0113 Intake air temp sensor high output.

Checked Crank Sensor KOIO Battery voltage on power wire, .1-.2ohm on ground wire. Back probed signal wire and spun crank with 1/2 ratchet and got a good square wave of 11mv-5v. Checked signal wire and ground from crank connector to ecu and getting .4ohms.

Checked Cam Position sensor KOIO and found the same as above.

Clear the codes, crank engine with no fuel (pump switched off and injectors unplugged), check again, and the codes are back. Any combination of fuel on cranked or anything, and codes come back after clearing. Evo Scan is logging RPM during cranking and attempted starts.

Checked ECU connectors and found all to be secured. No apparent damage to any wiring. Battery Cables secured and clean.

This all leads me to believe the ECU may be the culprit. I opened the case and checked for anything obvious. Im not sure but it appears there may be some oxidation. Ill attach photos.

My only other though would be some kind of signal interference from other wiring, such as injectors? I unplugged the resistor jumper (killing power to injectors) and got the same results and codes during a dry crank attempt.

Is there any way to confirm ECU is the issue before I shell out $300 for another EVO8 ECU. Or maybe something else that I have not checked yet.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[wing3r09]

Evo 8 ECU In 2g Works!!

I wasnt really having "phantom knock" problems..mine would knock from 3 to 7 counts when I stabbed the throttle at 3000-3500rpm. I have seen that described as "tip-in" knock. I have raised the low multiplier from 13 to 15. The mid is still 18 and the hi is untouched at 21.. I have seen no knock...

www.dsmtuners.com

Wondering if this is the reason for my P0335 and P0340 codes. However, the post indicates that it should still run. This is the same setup that ran last year.. but for 30$ from STM to get rid of these codes and try.. might be worth it.

 

[Galant665]

Been running an Evo 8 ECU in my 94 for 15 years. I’d try that ECU in an Evo. Flash in their map. Make sure the ECU itself is good. But the codes coming back like that. Have seen it with sensor grounds or one of the main grounds of the ECU to the chassis as being intermittent. If that temp circuit isn’t reading. Have also seen the ECU not want to start or be very inconsistent starting.

 

[wing3r09]

If I had someone to swap the ECU into, I would definitely give it a go. However, at the moment that is not an option for me.

I did some more testing and troubleshooting, trying to find the cause of the IAT code, P0113.

IAT sensor unplugged w/ KOEO, IAT connector is getting 4.7v. Sensor unplugged, and ground is getting 0.1ohm. Signal from connector back to ECU .01ohm.

Sensor plugged back in and back-probed, KOEO sensor is reading 2.2v with a multimeter. A heat gun causes the voltage to drop. However, EvoScan shows airtemp as -65c, and MAF airtemp scaled as 25c. EvoScan says to use MAF airtemp scaled for vehicles newer than 1996. When heat gun is applied, neither value changes in the logger.

So I'm assuming sensor is working as it changes voltage with heat. Im leaning toward ECU is faulty and not reading the value correctly. But without swapping it into another or getting a loaner, I’m not 100%. But I feel I’ve exhausted all other options here.