Reroute surgery saves Geo Metro

Get the jumper cables; this Geo is flat lining! Three technicians rush to the stall where a little blue 1993 Metro is barely clinging to existence. The shop’s top drivability technician works feverishly to bring the engine to life.

“It’s got spark and the fuel pressure looks good,” shouts the tech. “Hit the key again!” …Still, no life. Had “Old Man Winter” claimed yet another victim?

After a quick consultation through their ALLDATA automotive information database, one of the techs rushes to the stall with a factory technical service bulletin that mirrored the Metro’s symptoms exactly.

According to the bulletin, some 1993-94 Geo Metros may exhibit no start, hard start, low power and poor drivability conditions during cold (less than 0 Celsius) weather. In addition, diagnostic trouble codes 31 or 32 may be set. The Vehicle Identification Numbers are as follows:

1993 Vehicle Identification Numbers:

Metro XFi P67O8773 (CAMI)

Metro LSi P672431O (CAMI) or PK2O3427 (Kosai)

1994 Vehicle Identification Numbers prior to:

Metro XFi R674787O

Metro LSi R6747847

The bulletin further stated that moisture, trapped in the engine vacuum line between the Throttle Body Injection unit and the Manifold Absolute Pressure (MAP) sensor might freeze, resulting in a loss of signal from the sensor. If left uncorrected, the moisture may eventually migrate to the MAP sensor, resulting in possible sensor failure.

The correction is to utilize revised engine vacuum hose assemblies with an improved routing, which is designed to eliminate the possibility of future moisture accumulation. Additionally, check for the presence of any engine diagnostic trouble codes and take appropriate corrective action. Upon completion, install the new hose routing overlay, which is supplied with each kit, under the hood.

Following the procedures described in the bulletin, the technicians inspect the MAP sensor vacuum lines and sure enough, water is trapped inside. They quickly replace and reroute the lines with new ones supplied in the kit.

“Try to start it again,” yells the drivability tech. The engine roars to life – high fives and handshakes all around. This shop’s well-informed staff of professional technicians has saved another vehicle from winter’s deadly grasp.