Eliminating Cold Start Valce and ECM upgrade
 

Hi All,

I'm confused. I want to eliminate the cold start valve/switch setup on my 86 and I read that I have to upgrade my ecm to a 1989 ecm ???

The FAQ says that my 86 and an 89 are the same part number or model . So do I look for a 1227165 specifically from a 1989 vette? That might be tough since most used ones are of unknown origin. How can you tell if a 1227165 is from a 1989?

1985 – 1226870
1986-1989 - 1227165
1990-1991 – 1227727

Thanks
Lee

I would think you would have to change the chip to an 89 program. I just unplugged mine though. Can't tell the difference.:thumbs:

All that is really needed is to reprogram the values in the crank fuel pw vs. coolant temp table and also double the crank fuel pw scalar so that they are equal to the 89 values for rapid cold starts at low temperatures.

If the car isn't driven at extremely cold temps, it will probably be fine even without ecm tuning, with slightly increased cranking time. 0F to -40 F will likely be a problem, however.

An auto trans car may also benefit by upgrading to an 89 bin to take advantage of the 8192 diagnostics/scan capability, but you have to be careful with the spark advance since the heads are different between 86 and 89. Iron heads won't tolerate as much spark as the 113s. 128s should be similar and may be ok with an 89 tune.

Great. I sorta thought it would be something like that wih only values in the chip to be changed. My 86 has aluminum heads so I should be ok. Thanks a lot for the answer guys! Will do it soon.