duratec downgraded to 3-cyl

[ralph]

AIUI, those numbers should correlate only in that they are two slices of the 5.0v available; they shouldn't be remotely similar.  If your Easimap numbers are more in the 0.30-0.50v range, this is starting to look like the smoking gun -- maybe I do have some sort of mapping/config issue with the ECU, but it's probably not the voltage inversion...that appears to be by design and I'll confirm with a MM on the TPS.  Will update here when I've had a chance to push the TPS back to site=0.0 at idle and re-do the aperture and flow meter checks.

[KnifeySpoony]

Your ecu is fully unlocked right? Take the car for a proper dyno tune/mapping session? Costs money but You'll probably end up with a better map overall anyways. 

[sltous]

At idle:

Easimap: 0.41 volts, throttle site 0.3

Throttle Position Sensor: 4.61 volts

 

At approximately full throttle:

Easimap: 3.58 volts, throttle site 14.3

Throttle Position Sensor: 1.438 volts

 

9a4 Unlocked ECU, TPS Ford part number 988F-9B989-BB

Measured from TPS as shown in picture below, connected one test lead to signal wire and second test lead directly to the battery's negative terminal.

[ashyers]

Have you tried watching your Throttle Index Map live? This may give you some insight. On the earlier ECU's this map determined the voltage/throttle site relationship. Maybe in the later ECU's you could configure it as a rising or falling setup????

 

Andy

[ralph]

ECU is locked (stock Caterham -- so I don't even think I can view what map is loaded).

 

CC just told me that I should see 4.62v/site=0.0 (descending toward WOT) on Easimap.  I'm unconvinced.  What makes the most sense with what I've read an observed on the car is that the software is inverting the the voltage (5v system, TPS will read a high value at idle, Easimap will show 5v minus that value); as @sltous showed above, a MM probe on the middle wire of my TPS (with the other to ground) reads 4.60v - the inversion is real.  Not to mention, if my TPS voltage was aimed the wrong way, I would not expect the motor to behave well under load at higher rpms, where it is happily hoovering fuel and melting the rear tires.

 

I've gotten some great insights from Andy at PGM, and will likely be rewarding him with the purchase of an unlocked 9M4 with a slightly tweaked version of the RBTB config Caterham uses.  Really don't like the element of suspense/mystery in this story, and, besides, what could possibly go wrong if I have more access and control?!!

 

On the tach subplot, I may look at raising to 1PPR, since my tach now reads high, by roughly 2x -- still no rational explanation for why this would be necessary, still draws suspicion to the ECU config....

 

@KnifeySpoony (et al.) any recommendations for bay area local dyno tuning shops?

[KnifeySpoony]

I know of some reputable tuners but they mostly do Honda stuff, and most don't use easimap (hondata and emerald I think), though I don't know if that really matters tbh. The ultimate duratec engine builder/tuner (nationally AFAIK) is Hasselgren up in Berkeley (builds for formula Atlantic), but I dunno if he does "lower end" tuning or has a chassis dyno. And his rate might be insane. I would reach out to him though. 

[MV8]

A three terminal tps can be wired to ascend or descend with opening depending on where the leads are connected, just like any three lead potentiometer. It depends on the wiper versus the reference. Obviously CAT flipped the input and their software (to be proprietary/different I suppose) is made for that. I'd start with setting the warm idle bleed and timing, then adjust the sensor for the necessary voltage at idle. I know nothing about your idle air circuit system, software or any instruction but this is basic.