Running Too Rich For My Blood

[VegasBronco]

I've got a problem with my '89. I have to smog it to register it, yet it runs way too rich to pass. I've tried everything I can think of - new plugs/wires, new distributor, new MAP sensor, new O2 sensor, new diverter valve, new fuel pressure regulator, I can't think of what else I've done, but I can't think of what else to even try. Someone once suggested that I had a clogged injector, but they were changed in the Spring of '03 (to pass smog) and last time I changed the plugs, they were ALL fouled. Plus, sometimes when it idles, it's really rough and begins to smoke out the exhaust. If you've had similar problems or any ideas on what to try, please, feel free to add your input.


Thanks

 

[hawk2100n]

water temp sensor? it can cause it to run ritch because a broken sensor will always register as cold. there for the engine adds more fuel to compensate.

 

[1987moose]

I had a similar problem. Mine was the cat. Thing was pretty well clogged. If you can't get air out, you can't get air in, this will give you a rich condition. Good luck.

 

[Shadow_D]

I am sure you have already checked this but is the air filter new?
Are there any blockages between the outside air and intake?
Mice can get into anything and make a nest that will restrict the airflow if not block it completely. I have seen this problem, it's not that common but it does happen.

 

[Lou85bronco]

I had a problem similar to that on my efi before I converted.. Two problems caused it to run lean.. one was the egr valve itself.. check it make sure it is opening and closing correctly, and check the tube that runs to it. I had a hole in mine that was hidden (in the space through the upperintake ) that was causing the egr not to work correctly.

pull your air tubes off your tbi and start it.. this will tell you if its an air restriction problem...I would also try intake cleaner, cats, egr, smog system, I've found that a vacuum leak cause cause similar problems with the efi system on bronx try checking all that over. Gonna be a long trouble shootingprocess but youll hit it eventually.

 

[VegasBronco]

Yeah, I changed the coolant temp sensor, thermostat, had the cat tested by the same guys who installed my exhaust, changed the EGR valve and EVP sensor, my smog pump has good pressure, changed the PCV valve, fuel filter, air filter, breather element, like I said, I can't think of anything else. Could the timing be throwing it off this bad? When the shop checked my cat, they said that the timing was within spec, but if it isn't dead on, could that be it?

 

[Windchaser]

I wouldn't think so...I set my timing by hand and do just fine. I wish I knew what to tell ya there man, but you have tried everything that I could think of...I do know this, when I had mechanics trying to time my Bronx with the gun, my truck runs like shittocki mushrooms; too rich, doggy when idleing, and blowing black stuff out of the tailpipe. Try to time it by hand...hell you've tried everything else. Good luck >-

 

[tveronee]

A couple of other things to try would be the idle air control valve of the throttle position sensor. both of these along with the map sensor or mass air meter control how rich or how lean the engine runs. If it is the mass air system check all of the connections where it plugs in and clean it if necessary, I use Brake Cleaner
just be careful not to damage the sample tube. On the Map setup check the vacuum line going to it. Finally the idle air control valve can build up carbon deposits inside and not function properly. That can generaly be cleaned but its best to replace it. The throttle position sensor tells the computer how far the throttle plate is open but if it has a dead spot or a short it can cause either condition. I have seen the opposite with the t.p.s. on several occations but i would imagine it could go either way. Good Luck!