K20 A2 with PRB ECU in Lotus Elise, MAP values negative

kamannolli · Post by **kamannolli** » Mon Jun 09, 2008 8:10 am

Engine is a european K20 A2 from 2005 with JR supercharger, 3.4" pulley and Siemens 630cc injectors in a Lotus Elise. I have installed a PRB ECU with wideband O2, following the Hondata instructions depending the modifications of wiring. Uploaded calibration is "k20a2-rsx-650cc-jrsc-10-psi.kal" as proposed by the european distributor. Modifications: Injector size 630cc, TPS was calibrated at 0% and 100%, lean protection at 14.2 over 0.4 bar boost. The engine starts without any problems and idles constant, but it is not possible to drive it over 2.500 - 3.000 rpm. The MAP value is negative and there is no speed signal (see attached datalog). What is wrong?

magnEsium · Post by **magnEsium** » Mon Jun 09, 2008 11:12 am

what engine is the K20A2 out of? A civic?

I believe you have to relocate the MAP sensor with a S/C

but that might only be needed on a K20Z1 engine

and btw, you are seeing boost but not alot, like .4psi lol

Post by **Spunkster** » Mon Jun 09, 2008 1:45 pm

You problem is you have a doughterboard communication error. This is most likely caused by low battery voltage. Your battery may need to be replaced. THe cranking voltage canot drop too low or it will cause this.

kamannolli · Post by **kamannolli** » Mon Jun 09, 2008 2:39 pm

I remarked that in that datalog which i attached. After charging the battery i made a second try and didn?t got the daughterboard communication error. But the syptoms when driving the car where the same. Is it possible that the daughterboard communication error caused the faults like negative MAP values? Should I load the calibration once again?

kamannolli · Post by **kamannolli** » Mon Jun 09, 2008 2:47 pm

magnEsium wrote:what engine is the K20A2 out of? A civic?

I believe you have to relocate the MAP sensor with a S/C

but that might only be needed on a K20Z1 engine

and btw, you are seeing boost but not alot, like .4psi lol

Engine is out of a Civic Type R ?05. It was just running with a KPro PRA ECU and the MAP sensor at the same place.

Post by **Spunkster** » Tue Jun 10, 2008 9:28 am

I'm not sure what you mean by negative map values. When reading vacuum the numbers will be negative...this denotes that you are not in boost. It also depends on what units you are using.