Cold Start UP- Erratic Behavior
My 1999 146ti (alloy top, 100000 miles) has developed a strange fault lately. It happens when it’s cold at start up. First, as usual it climbs up to 1500 rpm then drops suddenly to 900-1000 for a fraction of a second then goes back up to 1500. This was the first symptom something was wrong.
Now along with the erratic behavior it miss fires for about 1-2 minutes. Once it warms up it runs fine. This only happens at cold start-up, the rest of the day it’s fine and starts with no miss fires.
I know for sure that the lambda probe is dead cause I got the ECU scanned a few months ago. I am now suspecting that the MAF is on its way out. It doesn’t kangaroo but is does shutter a little below 2000rpm. I drove it a whole day with the MAF unplugged and it did seem to run a little better, but not much different.
I am hoping the problem is just the lambda probe; the MAF for the alloy top engine is very expensive…
The car was purchased used with no service history other than talking to the mechanic that changed the belt & tensioners. I suspect the sparkplugs have never been replaced.
Any opinions are appreciated.