Closed loop MAP cutoff not working...

hackish · Post by **hackish** » Mon May 21, 2007 11:06 am

Last night I tuned a customer's ITB setup. He was using the TWM units on an ITR engine. I was not able to get the fuel cut to work properly. At really low throttle positions it kept cutting so I tried to adjust the maximum MAP value for the cut but I believe it's not working as described. I think this value is either the TPS is below that set value OR the MAP is below the value. You may need to check what you've found in the ROM but it is also possible that the units are just screwed up. On cruise I was seeing about 400-500mbar. On run-down I was seeing MAP values of 600-700mbar. The default value was 128 so I tried raising or lowering it but neither stopped the engine from cutting during cruise. I tried values as low as 0 and as high as 999. -Michael

Post by **calvin** » Tue May 22, 2007 9:58 am

try changing the tps value.

Post by **calvin** » Sun May 27, 2007 8:13 pm

gaskleppie can explain. it works. Because his kept going out of Fuel cut.. He had to raise the mbar

Post by **Gaskleppie** » Mon May 28, 2007 7:54 am

On cruise I was seeing about 400-500mbar. On run-down I was seeing MAP values of 600-700mbar.

So that engine pulls more vacuum at cruising than on run-down? What do you mean by run-down? Running down a hill or just letting it roll out off throttle? I had some issues with fuel cut but that was about the opposite. Off throttle my B16 pulled only 170mbar so the stock 128mbar was'nt enough to keep it in fuel cut. Setting the mbar to 175 solved my problem. Your problem seems the other way around. It never goes in fuel cut because of the high mbar at run-down. I think the fuel cut only works when both variables are ok. So below 3% throttle AND more vacuum than 128mbar. maybe if Calvin can make it so that you can choose to work with throttle position only your problem would be solved.

Post by **nate** » Wed Jun 20, 2007 12:29 pm

Michael, What is the status on this?