Running Rich

[pottsg]

Hi All,
My 1990 Ram 50 is running rich. What should I do. Lot of black soot coming from exhaust. I am going to run some sea foam thru the gas the truck has been sitting for 2 yrs. It has a new head, radiator, fuel pump, and computer. Thanks for your help.

[recian]

computer.. i can assume it's a 2.4L? The engine would be useful because a 2.0L is carb'd and a 2.4L is fuel injected and both have different reasons for running super rich. If it's fuel injected I'd look into a leaking fuel injector or maybe a bad ignition system like worn wires/plugs/distributor. Odds are low it's mechanical since it's got a new head. That eliminates valve issues.

[pottsg]

sorry, it is a 2.4 i have already replaced cap, rotor, plugs and wires. the resistance on the coil reads 12.89 so it should be good too. also the resistance on the throttle position sensor is good both at acceleration and without.

[pottsg]

plugs are gapped @ .044 per specs.

[LSR Mike]

o2 Sensor is probably bad, ECU is running in limp mode to avoid damage to the engine.

[recian]

Yep. 02 is what controls the mixture for fuel and if the vehicle sat up it's possible it's gone bad. Older ones dont last long and most of them are supposed to be changed at 30k.

[ikeepzitclean]

I'd have to agree..since its fuel injected and u already changed the sparks, plugs, and dizzy it has to be ur O2 sensor. try this: http://www.bmaautoparts.com i've used them for a lot of parts for my german cars, but they carry a wide selection of parts for other makes/models too. i bought an O2 sensor (along w/ many parts) for my ram50 too. anything ovr $50 is free shipping. hope this helps

[sleeps]

When is it running super rich? All the time, before or after it warms up? More info would help.

[LSR Mike]

When is it running super rich? All the time, before or after it warms up? More info would help.

This question brings into play the water temp sensor.

[ikeepzitclean]

im confused.. how does the water temp. sensor affect air/fuel mixture, hence the rich running?

[LSR Mike]

The water temp sensor is in the the loop for warm-up enrichment, kinda like a choke on a carburetor system. If it's bad, the ECU thinks the engine is cold and keeps the choke on. The ECU sending unit is a different one from the gauge sending unit.

[sleeps]

^ Exactly.

[ikeepzitclean]

The water temp sensor is in the the loop for warm-up enrichment, kinda like a choke on a carburetor system. If it's bad, the ECU thinks the engine is cold and keeps the choke on. The ECU sending unit is a different one from the gauge sending unit.

ohh that makes sense! thanks for explaining it...i confused myself, i was thinking of a carb'd, not FI (ECU). He did mention above he had a 2.4L :bang: lol


any luck pottsg?