est problem

[eddie20875]

on my 90 vette-L98 have had a code 42 show up. after going thru a lot of bs got the car running again and it pops on code 42 occassionnally. the timing is set to 6 btdc. everything has been replaced. i did put a new ecm and the code came up. if i put a used one that i got it doesn't. is there any kind of sensor that controls the est besides the ecm that i should check?. thanks for any help.

 

[wishuwerehere82]

The MAP sensor is the unit that senses manifold pressure and tells the ECM to advance or retard the EST control. You might just have a bad EST module.

 

[eddie20875]

thanks for the help. i would assume the est module is on the distributor?

 

[wishuwerehere82]

In the distributor, under the rotor.

 

[vetteboy86]

Could also be a connection problem. There is a one wire connector that is unplugged when setting the base timing. I would check through that connector.

 

[geekinavette]

In the distributor, under the rotor.

That is the solid state ignition module (electronic version of "points")...not the EST module?

I'm sure it's different on a '90....but in '84 they stuck the EST module over on the pass. side of the engine bay, right by the heater blower motor.

If we're talking about the same thing....