fiestaturbo.com

[sparkyt]

Hi i have running issues with my rebuilt engine, have checked or changed all sensors but it still judders up to turbo coming on song.

My question is how do i check the signal for the CO pot and map sensor is getting to the ecu pin numbers etc.

What voltage, or resistance should be at which pins
I am a sparky so have necessary test equipment just not the knowledge of which pins do what etc
Pls any help greatly appreciated thanks in advance Tim

[4992jk1]

the co pot signal should go to pin 27 on OFAC and pin 8 on OFAB
the map signal is an oscillating signal (on and off at about 160hz i think) to pin 45 OFAC and 27 OFAB

[sparkyt]

hi what should i be checking for on pin 27 as mine OFAC. Is it a change in voltage ? Only askin as my car juddering off boost but adjustment of the CO pot doesn't make any difference therfore making me think the CO signal not getting to ecu. Any help pls . many thanks in advance for any info. TIM

[4992jk1]

the co pot is a fixed voltage, it basically takes the place of exhaust sensors on later cars, it tells the ecu how rich to make it

[sparkyt]

If the Co pot signal is a fixed voltage what changes is it the resistance? Also are the other two pins 12v and ground ? thanks tim

[4992jk1]

one pin of the copot goes to ground, the other to a 5v reference voltage from the ecu, the ecu is preprogrammed with a map, the copot signal basically acts as a multiplier for that map, it doesnt change in normal running, it should be set once and then left, but it must be set by someone who knows what they are doing else the engine will be forced to run rich/lean, either way not a good prospect

[sparkyt]

thanks just what i needed to know, co pot has been messed with and car now jerks when i ran it for all of 20 feet down road then parked it up as dont want to damage my newly rebuilt engine. Just wanted to check that the signals getting to ecu before it gets trailered off for a tune. So cheers for info can now test wiring before she gets tuned. Many thanks Tim