13-11-2013
VEMS 1.2.18 install to standard Volvo 960 B230FT with camsync (sequential) and Crane HI6 CD ignition.
Original Volvo 60-2 VR flywheel sensor
Volvo 740 Hall distributor on camshaft for camsync
AW71 auto gearbox.
Running firmware 1.2.17 for 1 month, and now 1.2.18
Try to improve fuel economy, which is lousy (8,1 km/l mixed) with original ECU.
With VEMS, now running 9,5 km/l mixed driving, but still tuning it.
EGR : exhaust gas recirculation
Many factory engines recirculate a small amount of somewhat cooled exhaust gases into the intake at part load (cruise).
- might help a bit with emissions
- increases MAP somewhat, and decreases "pumping losses" (==drawing in air through a significant pressure drop across the almost closed throttle) and therefore slightly improves fuel economy
Does this engine have EGR valve ? (looks like an oversized IAC valve).
- if yes, is it PWM or stepper type ? (how many pins, what resistance ?)
- Do you plan to use it ?
- relying on EGO correction only (less fuel despite the higher MAP), or also some anytrim ?
- if you find that under some static cruise (perhaps in a temporary setup) the injector pulsewidth can be reduced significantly (eg from 4 msec to 3.6 msec) by some EGR-valve setting, than it might worth to apply some fw-mod for that strategy (in some ways similar to the tank-evaporator-canister purge valve, which is also enabled at certain part-load situations, enabled gradually, and dumps to the intake manifold).
Thanks for the EGR tip. Have not thought about that.
My engine has no EGR, but a 2 wire PWM valve operating at 100Hz (Volvo 940 standard freq).
I have no plans for a EGR valve, (have not seen any 940 in DK with EGR) but right now I am experimenting with hot air inlet at cruise speeds to try improve economy. At cruise I bypass the intercooler letting hot air (35-45 degrees) into the intake. I don't know if this will improve economy, only time will tell.