Found out my AP1 isn't making power when Dynotuning
05-10-2017, 04:06 PM
#11
Thread Starter
Based on the abnormal spike at 6300rpm and what Evans tuning said, i think there is a problem that needs further exploration. Unfortunately when you ditch the stock for a full EMS you lose your CEL function, which can be crucial to effectively troubleshooting issues with the engine. You might consider putting that back in and see if one gets triggers now or down the road.;$:
Just throwing this out there, but vtec dropping in/out could cause a dyno graph that looks like this. The peak power being lower then expected is hard to gauge if an issue or not.
A clogged cat or exhaust obstruction in the cat back would be the other possibility that could cause this.
I would assume its not a fuel or timing issue since Evans went through those parameters when tuning the car.
Other then a engine mechanical issue, I dont know what else would cause this. How confident your valves are adjusted correctly and didn't over tighten/cook a valve recently?
Just throwing this out there, but vtec dropping in/out could cause a dyno graph that looks like this. The peak power being lower then expected is hard to gauge if an issue or not.
A clogged cat or exhaust obstruction in the cat back would be the other possibility that could cause this.
I would assume its not a fuel or timing issue since Evans went through those parameters when tuning the car.
Other then a engine mechanical issue, I dont know what else would cause this. How confident your valves are adjusted correctly and didn't over tighten/cook a valve recently?
the valves were adjusted to factory spec by a mechanic that does this all day long. Before I installed the Haltech I was running my stock ecu for years and the car felt the same and never gave me a code. If need be I can always plug it back in.
Evans did say he didn't think it is a fuel issue because the car runs great up until the higher rpm. For now I'm going to swap the exhaust and see if that makes it better.
can it be a bad vtec seleniod or something ?
05-10-2017, 04:25 PM
#12
the valves were adjusted to factory spec by a mechanic that does this all day long. Before I installed the Haltech I was running my stock ecu for years and the car felt the same and never gave me a code. If need be I can always plug it back in.
Evans did say he didn't think it is a fuel issue because the car runs great up until the higher rpm. For now I'm going to swap the exhaust and see if that makes it better.
can it be a bad vtec seleniod or something ?
Evans did say he didn't think it is a fuel issue because the car runs great up until the higher rpm. For now I'm going to swap the exhaust and see if that makes it better.
can it be a bad vtec seleniod or something ?
Well that was my first inclination with regard to vtec. The unit is comprised of 2 circuits to make it function properly, the pressure switch and the solenoid. Each one has its own code and will trigger if either one of these circuits malfunctions. Ive encounter this issue myself. But with a CEL in general there seems to be some kind of threshold in frequency(how often) or some other factor before the problem gets triggered, which can make things confusing/annoying. Could be your situation, may not. Low engine oil pressure can effect vtec function. I assume you keep your oil level closely monitored. Oil pumps can go out though. But again usually a flickering or solid oil light comes up but not before you usually have enough miles on the motor to wear something else out first. It may be worthwhile to go ahead and pop the vtec unit off though and check the screen for any shavings/blockage to help rule out some form of mechanical stresses with the engine that could be effecting its performance and vtec function.
Last edited by s2000Junky; 05-10-2017 at 04:29 PM.
05-11-2017, 01:20 AM
#14
How do the spark plugs look? Maybe engine is running too lean or rich?
05-11-2017, 03:38 AM
#15
Thread Starter
Wouldn't I get a CEL if the car was running too rich or lean? I never had any codes with my stock ECU ...
im going to make some full throttle pulls and then check the plugs maybe that will show something.
im going to make some full throttle pulls and then check the plugs maybe that will show something.
05-11-2017, 10:48 AM
#18
The inability to lower VTEC is more likely restated: Jeff (Evans Tuning) lowered VTEC but the car didn't respond favorably. Jeff knows his shit, especially with the s2000. I've had my car tuned by Jeff twice and will be going back a 3rd time in early June.
Anyway, I'd look into whether the VTEC solenoid is working as expected. Could also be that the rocker arms aren't working properly (meaning it cannot reliably get pressure to transition to the high cam lobe). Basically it'd be a good idea to take the valve cover off and inspect it. Turn the crank through top-dead-center (TDC) for all 4 cylinders. Look for any signs of missing pins or wear in the rocker assembly, etc.
Anyway, I'd look into whether the VTEC solenoid is working as expected. Could also be that the rocker arms aren't working properly (meaning it cannot reliably get pressure to transition to the high cam lobe). Basically it'd be a good idea to take the valve cover off and inspect it. Turn the crank through top-dead-center (TDC) for all 4 cylinders. Look for any signs of missing pins or wear in the rocker assembly, etc.
