Friday, October 5, 2012

Fuel Running Lean

Engine Running Lean and Also check engine light is ON.

The Vehicle is 1999 Ford Explorer

Common problem noticed on fords and other vehicles too.

At our repair garage many customer visits with same types of issues like ...........

  • Lean running engine runs hotter
  • Running Lean
  • Fuel Bank 1 and 2 running lean
  • Fuel running rich lean
  • Car running lean fuel
  • Fuel injection running too lean
And many such other similar types of problems are noticed by customers.

In most of such cases the check engine light comes ON.
In that case the vehicle needs to be scanned for error codes which are stored in its engine control module.

On most of cases the error codes retrieved are 
C1230,C1102, P0443,P0171,P0174.

As for 1999 ford explorer vehicle. These problem is very common.On 1999 Ford Explorer it had known issues with leaking upper intake gasket and due to this lean codes get set. 
For this problem,as per our garage repair experience I would suggest you to start with installing a fuel pressure gauge to the fuel rail service port and make sure you have 32 to 45 PSI and if so, remove and replace the upper intake along with the mounting bolts and this should resolve the problem you having.If the fuel pressure is less then its required PSI,then i suggest you to get the fuel pump and fuel filter inspected and replaced.

This is what the error codes tell and explains.
The codes P0171 and P0174 are lean codes and are mostly set because the upper intake gasket is leaking and needs to be replaced.
Also because many other ford explorer 4.0 users have noticed same issue like yours and had complained about this ,so for these reason Ford has released a redesigned gasket set to correct this concern. 


  • The OBD code P0443 is usually a canister purge control issue but also low vacuum can effect this as well so the better place to start is correcting the intake leak and clear all code and see if any reset.
  • The codes C1230 and C1102 are in most cases set due to a bad rear speed sensor or the connection to it. The speed sensor is located in the top of the rear differential housing for ford explorer vehicle.
On most of such cases the OBD codes retrieved are P0171 and OBD code P0174.

These details will help.

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