running rich need help

[hondakilla98]

My car runs really rich and my gas mileage is about 12 mpg. It runs especially rich at idle. It was modified when i bought it so I think it has a bigger than stock cam. It is still speed density. I'm not sure where to start, any help would be great. Also it doesn't seem to have a rev limiter because I have hit 6k on the tach and it didn't hit limiter. Maybe it has a chip too?

 

[HISSIN50]

the stock tach is notorious for reading optimistically high.
some hit 7K before hitting the limiter.

have you pulled codes yet? that is where i would start. good luck.

 

[hondakilla98]

how do you pull codes?

 

[hondakilla98]

i was looking on another site and it sounds like my iac valve may need cleaned or replaced. Does this sound like a possible solution to anyone?

 

[HISSIN50]

i was looking on another site and it sounds like my iac valve may need cleaned or replaced. Does this sound like a possible solution to anyone?

if it idles alright, it would not be the first thing i do.

Jrichker has posted sites for pulling codes. a quick search will reveal them.

FYI, with no other info to go on, i would be lookin at stuff like: check ECT and ACT values (even if no code is tossed, they can be out of calibration), lambda sensors, etc. how much vac do you have at idle (you mention cam)? SD heavily relies on vacuum to help determine fuel/air mapping. if you have diminished vac from too big a cam, you might be messing the puter up. make sense?

that is what comes to mind right now. good luck.

 

[onpoint]

Check your fuel pressure. It should be between 36-40lbs depending on how you have your motor is set up.

 

[Daggar]

if it idles alright, it would not be the first thing i do.

Jrichker has posted sites for pulling codes. a quick search will reveal them.

FYI, with no other info to go on, i would be lookin at stuff like: check ECT and ACT values (even if no code is tossed, they can be out of calibration), lambda sensors, etc. how much vac do you have at idle (you mention cam)? SD heavily relies on vacuum to help determine fuel/air mapping. if you have diminished vac from too big a cam, you might be messing the puter up. make sense?

that is what comes to mind right now. good luck.

Yep, yep, yep, yep, yep. Those sensors out of range can cause your computer to remain in open loop mode. If those all check out then I'd go right to checking out what your vac is reading at idle. SD computers are by nature, "stupid" (makes SD cars more tunable by mechanical means). Low vac on an SD car will make the stock computer think you are accelerating and dump more gas in anticipation of makeing more HP an RPM. Nothing short of getting a custom chip burned with new fuel tables will fix a low vac condition caused by the cam. Fuel pressure is not even a concern at this point as the computer will either lengthen or shorten the duty cycle of the injectors at all power settings other than WOT based on what it thinks you're doing with the accelerator. In other words: lowering your fuel pressure to compensate for a rich condition at idle or part power won't get you anywhere. Don't be suprised if you don't get any codes at all. If the computer thinks that you're accelerating (due to what it sees your vac pressure at) then it will not consider a richer fuel mixture as a problem. Your other option at that point would be to convert to mass air. IT doesn't rely on vac pressure to make fuel mixture adjustments.

 

[DMAN302]

Too big a cam with SD can cause all kinds of problems especially if you have a vac leak..IAC will only affect idle not fuel curve.