Chrysler Repair: altitude, port fuel injection, cadillac seville

Question
Hello Roland;

We just moved from Ontario to Alberta...from 500 feet above sea level to 3500 ASL.  Our vehicles  run like crap now!  Even the lawn mower sputters with the same 87 octane gas!  It just seems like the ignition timing has been retarded a few degrees!  Is there anything that can be done to correct this problem?  We have a 96 Dodge Caravan 3 litre, and a 78 Cadillac Seville 350 with multi port fuel injection.  They were both running perfectly at the lower altitude.

Thanks in advance for your input.
Paul  

Answer
Hi Paul,
In theory things related to altitude ought to be less of a problem with fuel injection compared to carbureted engine like the lawn mower. The Manifold Absolute Pressure sensor should recognize the new thinner air and thus adjust the fuel so as to get the proper mixture. I am not familiar with why the MAP should not take into account your new altitude. It is programmed to sense that situation when you turn 'on' the key but before you start the car. It could be a learning period is needed?
I would suggest waiting a few moments between the "on" and the cranking position of you ignition key. Also, I suspect your cars are not unique in Alberta. Local shops probably have dealt with this sort of situation among newcomers. So why not inquire at Chrysler and at Cadillac dealerships, or independent tune-up specialists to see what they know. It may be possible to reprogram the engine control computer to modify the range of operation of the sensor or the logic part of the system.
If you learn something worth sharing I would be very happy to know of it.
Roland