2000 Ford Ranger Please help

DELTAM2

MEMBER
2000 FORD RANGER
6 CYL
4WD
AUTOMATIC
120,000 MILES

Truck sat idle (run 1/mo) during 18 month tour to Iraq (JAN 05 - JUN 06). Ran fine 1st month. Ck engine light and rough running. Replaced plugs & better for month or so. Rough and chk eng light again. Mechanic checked heads, compression, replaced 3X O2 sensors, plugs etc. Ran slightly better, but not 100%. Nursed for months due to $. Fuel mileage still poor, and fuel odor from exhaust still there. Changed eng with used in JULY 2008. Heads now cracked when checked. Truck ran very good for the last 5 months. Check eng lt came on 1 week ago. #4 misfire (same as on original eng). Ck'd fuel injectors, fuel rail, ignition quality/advance. Driver side O2 sensor not reading normal. FUEL PRESSURE reading 62 psi ! (First time we've checked this). Can this be the root cause? Could the long idle period have hurt the fuel pressure control? New PCV / Fuel filter. Injectors looked okay. More relavent info, but already seems longwinded. Thoughts?

1 Reply

JAMES W.

MECHANIC
2,394 POSTS

As a rule, a vehicle sitting for a length of time won't affect the FP regulator. Pressure specs for your truck are 30 to 45 lbs. At 62 psi, you're way over pressure by about 50%. What this means is, every time an injector fires you're shooting in about 50% more fuel than normal and the air/fuel ratio control can only operate correctly within a certain pressure range. You may want to change the regulator and retest your pressure. Also, you may want see if you have good vacuum to the FP regulator at an idle. Let me know.