Thought It Was Fixed Still Runnin Rich Code 91 Only

[joedirt76]

I don't think this is a normal problem ,this is gonna be long but please read and help , after lots of electrical test part swapping and replacing I am still running rich . as of now I am not using the pms it is on the bench stock computer only (a9p) , 36 # injectors replaced with 30# , correct calibration tube being used, maf properly cleaned , spark plugs are autolite 3924 gapped at .054 , base idle correct and tps at .99 , timing 14 degrees,o2 sensors replaced, o2 sensor harness completely continuity checked, all grounds checked and good , maf,map,and tps sensor checked and good . after all that I am pulling (code 91 only) and it just wont go away , ive cleared codes in ever fashion including battery disconnect to clear kam redrove reran test and 91 just wont go away , car starts and runs ok but is runnin rich enough the smell bothers u at idle , heres the kicker after parts replacement injectors , computer, plugs, and bypass pms ,the car ran so perfect I couldn't believe it !! but only lasted for that one run the next time I cranked 2 days later it was right back to runnin rich , please please help I am at total lost at this point , thanku in advance

 

[84Ttop]

Are you using a C&L Meter?

 

[joedirt76]

I am currently, I know everyone says there junk and pro-m supposed to be the way to go , due to lack of funds I haven't purchased one yet. I certainly don't know it all and hope to not offend anyboby in my lack of knowledge on some of this , but how can the meter alone throw that code , theres nothing electrical about it I would think maf sensor before the meter but then why not code 41 with it ?

 

[joedirt76]

just to be clear my mass air flow is a 76mm c&l with tube 099 for 30# injectors , the meter itself that plugs into harness is a stock meter

 

[Grabbin' Asphalt]

IMO the meter is critical in the amount of air/fuel mixture, .....so it is the BIG part on the air side to determine the Fuel side, any screw up in that dept and problems abound.

 

[Bullitt347]

The reason C&L meters have this issue is that they are trying to "trick" the stock MAF sensor into reading a certain amount of air flow. The stock sensor was calibrated for 19 lb/hr injectors, with the C&L meter, the sensor is still calibrated for 19 lb/hr injectors, but C&L is using a different sampling tube to get a different air flow across the sensor to offset the larger fuel injectors. Sometimes it is close enough, sometimes not so much.

 

[joedirt76]

good explanation that makes sense , but how is a pro-m gonna solve the problem if im still using 30# injectors and the sensor is still calibrated for 19#

 

[Bullitt347]

good explanation that makes sense , but how is a pro-m gonna solve the problem if im still using 30# injectors and the sensor is still calibrated for 19#

Because the Pro-M does not use a MAF sensor calibrated for 19 lb/hr injectors. They actually calibrate the sensor to the size injector you are using so there is no "tricking" of the sensor. The electronics inside the sensor have been changed (the air/fuel map or table is recalibrated) instead of changing how the air flows past the sensor.

 

[joedirt76]

ahhhhh haa, 10/4 guess ima have to invest your the first one who has explained it in a way that I understand , makes total sense now especially being it has always ran rich since the build , I will get one, and I will reply with a update to this thread as soon as installed !! thanks a bunch

 

[Bullitt347]

Glad I could help, keep us posted.

 

[joedirt76]

was gonna wait till weekend to give better update , but bought pro-m 80 installed last night , put computer back in that I let sit on bench and decay in codes hookup up scanner cleared codes again and turned the key , right away running completely different and as much as I hate to say its worst after meter change,still running rich I didn't mess with it long only long enough to warm up and run a koer to pull codes , 91 is gone for now only pulled 3 others and that's the stuff unplugged egr,thermatic etc. but still running rich , im starting to wonder if im just overfueling somehow ,too much fuel pump,or jacked up regulator maybe ?

 

[jrichker]

What were the numeric codes?

 

[joedirt76]

was in a hurry didn't write them down ,but I do remember 94, I will have better update and info this weekend ! work has me tied down till then

 

[madspeed]

to clarify, you now have a pro m meter calibrated for 30# injectors along with 30# injectors?

 

[joedirt76]

Yes sir

 

[madspeed]

do ou have a wideband o2 sensor and an afr gauge?

 

[joedirt76]

No , just replaced o2's with new stock Bosch ones

 

[joedirt76]

Was gonna try next checking my fuel pressure with different gauge just to confirm if pressure is correct or not , right now I have small gauge tapped right into pressure regulator but want to rule out if that gauge is defective or not

 

[madspeed]

If no wideband how are you sure its rich?

 

[joedirt76]

FUMES, bout died lastnite just letting it warm up lol