Fuel Injection problem - 87 Ranger
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Joined: Jun 2001
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Fuel Injection problem - 87 Ranger
HELP!! This is driving me crazy! My 2.9 V-6, fuel-injected '87 Ranger started doing this on a long trip last week:
When cruising or decelerating the engine starts running very rich, blowing black smoke out of the exhaust. This continues for maybe 5 seconds, then suddenly it starts running fine, then bad, then fine, etc.
It first started this after climbing several long hills. After cresting the hill and letting off the gas, the problem started. There is no problem when the throttle is wide open. It only occurs when I am cruising or decelerating, and will also continue to run bad for a few seconds after coming down to an idle, however within a few seconds it clears up and will then idle normally for an indefinite period.
Just to eliminate them as possibilities, I have replaced the following parts, however the problem continues:
Plugs, wires, rotor, distributor cap, fuel filter, air filter. The fuel pressure regulator is about one year old, and is not leaking fuel through the diaphram (at least it isn't blowing out the vacuum hose). Any ideas? I'm desperate!!! I have to pass smog next month!!
Gary
When cruising or decelerating the engine starts running very rich, blowing black smoke out of the exhaust. This continues for maybe 5 seconds, then suddenly it starts running fine, then bad, then fine, etc.
It first started this after climbing several long hills. After cresting the hill and letting off the gas, the problem started. There is no problem when the throttle is wide open. It only occurs when I am cruising or decelerating, and will also continue to run bad for a few seconds after coming down to an idle, however within a few seconds it clears up and will then idle normally for an indefinite period.
Just to eliminate them as possibilities, I have replaced the following parts, however the problem continues:
Plugs, wires, rotor, distributor cap, fuel filter, air filter. The fuel pressure regulator is about one year old, and is not leaking fuel through the diaphram (at least it isn't blowing out the vacuum hose). Any ideas? I'm desperate!!! I have to pass smog next month!!
Gary
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Joined: Aug 2000
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Fuel Injection problem - 87 Ranger
Gary, since it only does this at partial throttle, and not at wide open or idle, it sounds like a bad TPS (throttle position sensor) to me. There is a procedure for testing these in Haynes or Chiltons manuals. It might be worthwhile to test it before buying a new one.
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Joined: Apr 2000
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Fuel Injection problem - 87 Ranger
The TPS is a very good possibility, especially if you do a lot of cruising in the same speed range with cruise control. The constant fluctuation of the speed control wears the one spot out on the sensor, but everywhere else is still good. Disconnect the TPS and put an Ohm-meter on the sensor signal and the ground terminals of the sensor, and slowly push down on the gas pedal while watching the Ohm-meter. If it doesn't move in a smooth transition (if it jumps around), replace it.
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88 F-150 4X4 XLT Lariat w/5.0 EFI 5 spd (DAILY DRIVER)
86 Ranger 2WD w/2.3L EFI 5 spd to be 351W 4bbl C4 (NEW TOY- DETAILS WHEN FINISHED)
85 Old Cutlass Supreme 350/TH350 Holley 4160,Edelbrock Performer intake, el-cheapo headers, General Kinetics 270H series cam, 15.588 best 1/4 mile with original 10 bolt 2.41 gears (OLD TOY)
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