Hello all,
I have an 89 vette and craig's software which is great, is telling me that I am never getting into open loop. I have a 160 thermostat and was wondering if there is something to change in the ECM to enable the car to go into open loop at WOT. I would greatly appreciate any help anyone could provide. The car usually operates around 180-190 temp range. Thanks for the help in advance.

 

That variable is only stating that all of the ECM's requirements for closed loop operation have been met. You sort-of go into open loop at WOT (BruceP can explain it better), but the computer won't say so since the conditions for closed loop are still being met (coolant temp, engine run timer, and O2 swing).

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Greg Westphal
'87 IROC 355TPI/A4

 

Need more info...I think what your saying is that I am going into open loop, but the computer is saying to craig's software that I am still in closed loop because all the criteria for open loop has not been met, i.e. coolant temp. Will this hurt the performance of the car? And how do I change the parameters for the coolant, ect. THanks

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White 89 Corvette....
Open Air box
Relocated MAT
Air foil
160 Stat
Lower Coolant Sensor
13.6 1/4 mile Total Stock

 

While in PE(power enrichment mode) or WOT usually, you'll notice that the BLM and INT are locked at 128, which is normal, and you notice that while in open loop the same BLM/INT situation is occuring. Like you said the CTS is saying that your still in closed loop. But in a "sense" your really in open loop. The car doesn't need to be in open loop while in WOT.

 

Let me reword that, the car doesn't have to "say" openloop while in WOT/PE mode.

 

OK let me get this straight. Its OK then for the car to report in closed loop, so long as the BLM values returned are at 128 (which they are) during WOT. Thanks for the help.

 

Yep, or at least close to 128. I can't remember which way it goes, but if the BLM in cell 15 was either high or low, then it uses that correction in addition to the PE fuel tables. To sort-of answer your ealier question, you don't need to change the coolant value for entering closed loop since it's already lower than the temps your engine normally operates at (usually around 100 to 122 degrees F for TPI engines).

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Greg Westphal
'87 IROC 355TPI/A4