Sorry about the earlier post. For some odd reason, all your posts where not loading.
Lets start with the obvious. All fuel system require a working fuel filter to prevent clogging/contamination. If you bought the vehicle used and the previous owner bypassed the fuel filter, you can expect fuel system contamination. Is there a functioning fuel filter on the vehicle now? Are all the fuel lines ok? (No kinks or physical damage.) With a functioning fuel filter is the fuel pressure and supply ok? Does the fuel system maintain fuel pressure after the vehicle is turned off? (Is the fuel pump bleeding back?) If yes, then you can concentrate on the eng. Area fuel components.
Note: sometimes fuel pumps may have an internal failure that only shows up under load (climbing hill ) conditions. If everything checks out and problem only occurs under load, expect the pump to be the failure.
The fuel pressure regulator does not tend to clog. It will however leak or stick. Inspect it for external leaks and remove its vacuum line for signs of internal leakage.
The fuel rails should appear undamaged and show no signs of cracks or external leaks.
The history of the vehicle and your problem description is most likely caused by restricted injector(s). You can pay to have them cleaned. This is not always possible, especially if the vehicle was run for an extended period of time without a fuel filter. The injector(s) restriction is just too great. You may have to have them replaced. In your case, make sure the fuel system/lines are flushed to prevent the new injector(s) from being damaged by dirt from the lack of a fuel filter.
Note: intake/exhaust gasket problems will usually show up during a eng. Vacuum test. If the problem turns out to be injectors. The injector job time overlaps with intake gasket replacement time.
Lastly, your repairing facility/tech is not helping you out by not picking up on something so obvious. If they know all the info that appears in this posting and still can't pinpoint the problem. Its time to look for a new repair facility/tech.
Sunday, December 6th, 2009 AT 12:08 PM