I've got an 88 ford ranger, 6-cyl. with fuel injection and it seems to be running very rich. does anyone know how to adjust the fuel air mixture or know of any webpage that describes how to do this? I've got the Haynes repair manual but that doesn't tell you anything about how this is done. Thanks for any help you can give.
I'm not an expert, but I thought the furl mixture was set by the ECU based on what the oxygen sensor (in the exhaust pipe) reports. I would wonder if the O2 sensor is working -- Most vehicles need it replaced every so often, like every 60,000 miles.
--Mort
The only time it should run rich is when you first start the truck. The computer runs in an open loop mode for a little bit while the engine warms (typically only a few seconds to a few minutes), then the computer puts the O2 sensors in the loop and leans the mixture to a 14.7:1 ratio.
I'd definitely check the O2 sensors first and the associated wiring. Then the fuel pressure, regulator, pump, and injectors.
Also, the temp sensors...If the truck thinks it's cold all the time, it will run rich all the time, as it doesn't go to closed loop. I'd check the whole system out. In general, for an over rich, the temp sensors, O2, MAP, etc, would be the first places I'd look. Also make sure the filter isn't clogged.
Can't be done. The computer adjusts mixture using all the input signals it gets . You need a through system checkout to find out what input device went kaput. Have you pulled up any possible error codes? Check engine light on? MK
On Fri, 14 May 2004 17:16:33 -0700, Adam rearranged some electrons to form:
You can't adjust the mixture. It is controlled by the computer. You should read out any codes that may be set, this will tell you if you have any defective sensors. Your Haynes manual will tell you how to do this.
truck. The
engine warms
wiring. Then
Don't forget that the catalytic converter could also be bad. I went thru 4 shops with a similar problem on a 2.9L '88 Bronco II . )nobody had a clue( Ford shop did the usual O2 sensor;
I almost gave up and was ready to scrap it; but it was due for a muffler and the rest of the exhaust . I figured '' what ta hay"; ; had a good muffler shop "pull the cat" ; cut it open and there wasn't much left except a baffle that would "swing in the breeze" and damned near choke off the flow and "poison" the O2 sensor. .
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