Is there a way to lean fuel mixture?

[thewishkah]

Ok I heard that If your exhaust smells strong your running rich which kills gas mileage, now I know with a carb you can change the fule mixture , Im wondering If this is possible with my X since it doesnt have a carb. Im thinking I may be running rich since with my new exhaust it still smells really strong. thanks in advance for any help

 

[Glacier991]

There is no way to similarly adjust your A/F mixture on a computer controlled injection system. An overly rich condition mixture can be related to a fuel pressure regulator problem.

 

[Robb]

Physically leaning the mixture is a temporary fix to a REAL problem.

You need to determine what is enriching your mixture and fix it.

 

[MrShorty]

Does the check engine light come on while driving? If you pull codes from the computer (see "tests" at www.dalidesign.com/hbook/eectest.html), do you get any codes other than 111?

 

[thewishkah]

Nah my check engine light doesnt come on the truck just seems slugish, and wiith a new exhaust makes a very strong exhuast smell, but my idle rpm is kind of high which would make me think its lean? maybe? Im not really great when it comes to the fuel system and I get kind of weary of working on it cause I dont feel like killing my self and others around lol.

 

[performancenut]

Simply "leaning" the mixture based on smell could result in overall lean conditions and a resultant cracked piston, "burnt" valve, etc. To do business correctly, place it on a full diagnostic machine and measure parameters. Lots of possible causes exist; as previously mentioned you have to find the cause; right now you have simply identified a possible symptom. Might want to look at the fuel and intake system for starters: clean MAF sensor, check fuel pressures, etc.

 

[thewishkah]

See im not NEW to the car/truck world but I still dont know alot and living in NYC I dont have all the room I want to work (I wish I did) and being that I hardly have any room in my garage I dont have all the requierd tools/testers I would like to have so I guess id have to bring it in for these checks? thanks alot for your replies everyone Im just trying to figure out the reason for such bad gas mileage. I have done these steps to try and correct:
1)changed-air and fuel filters, and the PCV
2)new plugs and wires
3)sea foam
4)cleaned MAF
5)air pressure st 35 psi in wrangler rt/s
6) changed driving style- only gaind 2mpg from 8-10 mpg

Im stumped and I know running rich could lower mileage. So I figured I would ask thanks for any help again everyone

 

[00sport4x4]

speaking of rich/lean condition tell me this, why is it I can run my fingure around the inside of my exhaust tip and get no black carbon on it at all? I have changed the plugs, wires, kkm, t/b and change the oil like a period every 2,500 miles. I've owned it for 2 years, drive it daily and still no carbon. every other vehicle I own still has some carbon in its exhaust? Or is this a sign of things (very very BAD) things to come?

 

[MrShorty]

See im not NEW to the car/truck world but I still dont know alot and living in NYC I dont have all the room I want to work (I wish I did) and being that I hardly have any room in my garage I dont have all the requierd tools/testers I would like to have so I guess id have to bring it in for these checks?

You wouldn't have to take it in to a shop. The link I posted above has instructions for pulling codes using a paper clip and a test light (check engine light also flashes). Not all faults will turn the cehck engine light on, I think it would be worth the ten minutes it would require to run both the KOEO and KOER tests and see which tests it passes and which it doesn't. beyond that the sensors/actuators can be tested with a good DVOM. Actron (www.actron.com) makes a "sensor tester" that's essentially a glorified DVOM and has placed a copy of the user's manual on their website. I find it can be a useful resource for figuring out how to test EEC-IV sensors.

thanks alot for your replies everyone Im just trying to figure out the reason for such bad gas mileage. I have done these steps to try and correct:
1)changed-air and fuel filters, and the PCV
2)new plugs and wires
3)sea foam
4)cleaned MAF
5)air pressure st 35 psi in wrangler rt/s
6) changed driving style- only gaind 2mpg from 8-10 mpg

Im stumped and I know running rich could lower mileage. So I figured I would ask thanks for any help again everyone

It hasn't been mentioned, but a common cause of running rich is bad fuel pressure regulator. Check the vacuum line that goes to the FPR. If there's any gas in that vacuum line, the FPR is bad and needs to be replaced. If that's ok, get a fuel pressure gauge and see if the fuel pressure is where it should be.

 

[thewishkah]

thanks alot just one question what the FRP? thanks again

 

[MrShorty]

FPR=Fuel Pressure Regulator. Attached to the forward end of the fuel rail.

 

[thewishkah]

does anyone have a pic of a 94 push rod engine of the FPR? is it visible? cause i noticed something pretty rusty to under the hood today to the (right side) when lookin at it head on its round and has little holes in it? if not that anyone know what it is?

 

[Glacier991]

Shorty... check out post number 2 (grin). FPR was suggested.

 

[MrShorty]

My apologies. I didn't pick up on it. Likely, I either had a 2 mo. old on my lap with a bottle in her mouth, and/or one in the other room crying to have a bottle put into her mouth. I'll do better

 

[performancenut]

Dang; no mercy.

 

[Glacier991]

Hey if he can do all he does AND take care of babies, he gets MY vote for mechanic/Dad of the year ! (He's probably one of the very best guys to help others on here - and really knows his stuff! - I was teezin him)