engine diagnostic

Discuss which Sensors work best with these ECUs and share how you are using inputs and outputs
Post Reply
Cpur
Posts: 51
Joined: Wed Dec 06, 2017 1:55 pm
ECU Model: S100 Pro

engine diagnostic

Post by Cpur »

Hi all,
Today we had time to log some runs in the 1/4 mile raceway.

Had some misfires, we logged a lot of things but nothing seemed to be the start of this misfire.

I also noticed that the Stack rpm was falling when the misfire occurs, so it was definitely an input problem.
Later we saw the engine diagnostic display.

I had 3 concerens here

cam sensor 10
rejected crack pulses 8
synthetic tooth errors 4

Does the Cam sensor effect anything after the engine is in sync and running?
Do rejected crank cause misfire?
Do synthetic tooth errors cause misfire?


Thanks and Regards
Attachments
halfar errors.jpg
halfar crank scope.jpg
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: engine diagnostic

Post by Alex DTA »

If the RPM is dropping, then it's a signal issue from the crank or cam sensor.
However, you don't have enough of either error to have had more than two misfires, unless the diagnostics have been reset? The number of wheel pulses would suggest not.

The ECU will reset if the there are more than 4 cam/crank sensor errors. If you've had a number of misfires, then this is not the problem.
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: engine diagnostic

Post by Rob Stevens »

To add to what Alex says you have had 15 resets since last cleared, does that sound right? as in you turned the engine on and off 15 times.
Cpur
Posts: 51
Joined: Wed Dec 06, 2017 1:55 pm
ECU Model: S100 Pro

Re: engine diagnostic

Post by Cpur »

If i have misfires next sunday should i try it in wasted not sequential.
Will this eliminated the chance of the cam sensor errors interfering?

Regards
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: engine diagnostic

Post by Alex DTA »

Yes.
Make sure injectors are not in sequential, and coils are in wasted spark mode, and cam control is off

Send me a copy of the map if you want me to check it for you
Cpur
Posts: 51
Joined: Wed Dec 06, 2017 1:55 pm
ECU Model: S100 Pro

Re: engine diagnostic

Post by Cpur »

Hi All,

The missfires were probably coming from over boost cut. I need to check how does any cut work.
I saw that there are different cut patterns but i still didn't read this part.

Thanks guys
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: engine diagnostic

Post by Rob Stevens »

The overboost is a full cut and has nothing to do with the cut patterns, the overboost cut maintains cut to all sparks until the boost has dropped below its set point again. It's pretty brutal in its operation,
Alex DTA
Posts: 1622
Joined: Fri Feb 28, 2014 1:03 pm
ECU Model: S40 Pro
Distributor: DTA
Firmware Version: 79

Re: engine diagnostic

Post by Alex DTA »

I really need to make the overboost cuts clearer, as the answer to your question was there, and we all missed it.

As Rob says, it's a simple hard cut to the engine. It's to protect against failed waste gates/valves, which is why we don't use a PWM modification.
Post Reply