clt an iat temps.

For discussing how to choose sensors and create a wiring harness for all Bowling and Grippo versions of the MegaSquirt® EFI controller.
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snake
MegaSquirt Newbie
Posts: 12
Joined: Sat May 02, 2009 4:16 am

clt an iat temps.

Post by snake »

ok here goes the story. i switched code on my ms2 v3 to extra had bad luck with it, went back to regular code. 2.89. ever since i switched the code i started to get funny readings on the temps. i have re calibrated the therm tables an all that jazz. even tried a new sensor to see what would happen. i am gettin a extreamly weird signal. it maybe 30 outside the gauge will read 70 now as the engine wars up it jumps temp rapidly. within less than 3 minits it will go all the way up too 240. engines inst even warm yet. if i hit the lights an blower fan it will make the gauge even more inaccurate. the iat sensor also climbes way to fast and i think what it is reading is compleatly unreasonable. another thing is how do i set the cranking advance to nothin? i get mad kickbacks. and im only runnning 2deg advance in the spark table. this is the main starting problem being as it is getting colder out. any an all info would be appreciated.
Matt Cramer
Super Squirter
Posts: 2951
Joined: Sat Jul 03, 2004 11:35 am

Re: clt an iat temps.

Post by Matt Cramer »

About the kickbacks: What sort of ignition are you using?

For the temperature readings, does this problem happen on the Stim too, or just the car? What calibration settings are you using?
snake
MegaSquirt Newbie
Posts: 12
Joined: Sat May 02, 2009 4:16 am

Re: clt an iat temps.

Post by snake »

i am using direct coil control. last time it was on the stim it seemed normal. went up an down like it should have with the pots.
when i look at the logs it goes from regular temps to just wild swinging. hold 180.1 then jump to 300+. then swing back. it usually reads insanly high all the time for some reason. i have tried a couple sensors, with no avail. they are just a standard nail head single wire(bosh). the settings i used were for the bosh sensors in tuner studio. it also seems the colder it gets the worse the kicking back is. i did move the distro 20 degrees in retard and added 20 degrees to the spark table. this was in an attemp to try and cure the kickbacks which it did for a short time.
Matt Cramer
Super Squirter
Posts: 2951
Joined: Sat Jul 03, 2004 11:35 am

Re: clt an iat temps.

Post by Matt Cramer »

What's your trigger angle? Using a wheel decoder?

Single wire sensors are notoriously noisy. There are a couple different Bosch sensor types with different calibrations. I'd double check them with ice water and boiling water to make sure the Bosch defaults are right for your Bosch sensors.
snake
MegaSquirt Newbie
Posts: 12
Joined: Sat May 02, 2009 4:16 am

Re: clt an iat temps.

Post by snake »

well this sensor type did work ok at one time not to long ago. i have already used the ice water and the boiling water trick and i have the right resistance scale. i am using a distributor. an trigger angle is at 60
Matt Cramer
Super Squirter
Posts: 2951
Joined: Sat Jul 03, 2004 11:35 am

Re: clt an iat temps.

Post by Matt Cramer »

Measure the voltage at the sensor when it's reading around 70 and around 240 - let me know what voltage you see there. Also, exactly what resistance values did you put in for the calibration curve?
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