Rich at idle after cam
06-30-2003, 10:20 AM
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Rich at idle after cam After installing my TR224 cam I am really rich at idle. I'm talking burn your eyes rich, but when I checked my LTFTs they are great (0 and .8). What should I mess with to get it together at idle?
06-30-2003, 11:33 AM
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Re: Rich at idle after cam Not exactly sure on this one, but I believe "burn your eyes rich" is actually lean!
Check your O2's and see if they are white'ish color=lean. Or Plugs.
Check your O2's and see if they are white'ish color=lean. Or Plugs.
07-31-2003, 01:29 AM
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Re: Rich at idle after cam Are you in closed loop?
I fixed my rich problem with a twist of the idle screw. I got my IAC's down to 50 from 120. Didn't have to do anything in EDIT except to raise the idle to 775
I fixed my rich problem with a twist of the idle screw. I got my IAC's down to 50 from 120. Didn't have to do anything in EDIT except to raise the idle to 775
07-31-2003, 10:56 AM
#6
Re: Rich at idle after cam I had this problem after my TR224 install and have been trying a few different things to correct it. Mine has been doing that for both hot and cold idling, and in both closed and open loop. I've had the most success by changing the Main VE table from 400 to 1200 rpm. People say to scale it 60% to 80%. Well, 80% wasn't enough, still idled rich but better, so I went with 60%. That cleaned it up but caused a bog or hesitation. Nic00Z28M6 on this board progressively scaled his with good results, so I tried that and it seems to be working well so far: 1200 rpm = 80%, 800 rpm =70%, and 400 rpm =60%. You can also mess around with Open Loop F/A table if it only does it before you go into closed loop. I may go back to this table and make some changes once the weather gets cooler. I've also changed the idle speed to 950 with edit which cleans it up a bit.
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08-01-2003, 07:14 AM
#9
Re: Rich at idle after cam [quote]
Nic00Z28M6 on this board progressively scaled his with good results, so I tried that and it seems to be working well so far: 1200 rpm = 80%, 800 rpm =70%, and 400 rpm =60%. [/qoute]
Good advice, I think I might play around with that a bit.
So this would apply mainly to cold starts then? 
Nic00Z28M6 on this board progressively scaled his with good results, so I tried that and it seems to be working well so far: 1200 rpm = 80%, 800 rpm =70%, and 400 rpm =60%. [/qoute]
Good advice, I think I might play around with that a bit.
You can also mess around with Open Loop F/A table if it only does it before you go into closed loop.
08-01-2003, 10:27 AM
#10
Re: Rich at idle after cam
So this would apply mainly to cold starts then?
08-01-2003, 03:09 PM
#11
Re: Rich at idle after cam There are several solutions to your problem. If one doesn't work, try another.
1) The VE table solution. Described by CAL. I'm not a big fan of this solution for idle problems. The VE table determines your base PW for your injector fueling. If it is too small, you will get the hesitation as descibed above. The VE solution will fix your problem, but there are better solutions in my opinion.
2) Raise your idle. Idling a large cam too low will generate many drivability problems. Your cam should idle between 800 and 1000 rpm.
3) Partial open loop solution. You can directly control your fueling by forcing your car to open loop for idle operation.
Cams and aftermarket exhausts have a tendecy to confuse O2 sensors. Meaning, they can cause your car to unecessarily dump fuel. Your LTerms may say that every thing is fine, but common sense (rich gas smell, smoke) should tell you its not.
To kick your car to open loop partially, change all points in the WOT Hot and Cold tables for all RPM up to 1600 to zero. Now, you can directly use your PE table (at these RPM points) to control fueling.
This solution works fine, but can cause surging if your PE table has too much of a step change (ie 1.5 at 1600 rpm to 1.24 at 2000 rpm)
4) Full Open Loop. Personally, I can't stand oxygen sensors. On a near stock car, they are great. They improve your fuel economy, make you emmissions compliant, and provide a reliable a/f ratio. On highly modded cars, they can be a different story. Many of the modifications that we do to our cars confuse the oxygen sensors. So instead of providing reliable a/f ratios and good gas mileage they acutally do just the opposite. They have a tendency to drag your a/f ratio either too rich or too lean (usually too rich) because of false readings. You don't find O2 sensors on cars that do not have to meet federal emmissions regulations (like the middle east). Our cars run just fine without oxygen sensors, and from a tuners perspective, usually better.
To kick your car to full open loop change all values in the Open Loop Enable Temp table to 300. To control vehicle fueling hook up a wideband and use the Injector Flow Rate table to dial in an a/f ratio of ~14:1.
Good Luck,
Kevin
1) The VE table solution. Described by CAL. I'm not a big fan of this solution for idle problems. The VE table determines your base PW for your injector fueling. If it is too small, you will get the hesitation as descibed above. The VE solution will fix your problem, but there are better solutions in my opinion.
2) Raise your idle. Idling a large cam too low will generate many drivability problems. Your cam should idle between 800 and 1000 rpm.
3) Partial open loop solution. You can directly control your fueling by forcing your car to open loop for idle operation.
Cams and aftermarket exhausts have a tendecy to confuse O2 sensors. Meaning, they can cause your car to unecessarily dump fuel. Your LTerms may say that every thing is fine, but common sense (rich gas smell, smoke) should tell you its not.
To kick your car to open loop partially, change all points in the WOT Hot and Cold tables for all RPM up to 1600 to zero. Now, you can directly use your PE table (at these RPM points) to control fueling.
This solution works fine, but can cause surging if your PE table has too much of a step change (ie 1.5 at 1600 rpm to 1.24 at 2000 rpm)
4) Full Open Loop. Personally, I can't stand oxygen sensors. On a near stock car, they are great. They improve your fuel economy, make you emmissions compliant, and provide a reliable a/f ratio. On highly modded cars, they can be a different story. Many of the modifications that we do to our cars confuse the oxygen sensors. So instead of providing reliable a/f ratios and good gas mileage they acutally do just the opposite. They have a tendency to drag your a/f ratio either too rich or too lean (usually too rich) because of false readings. You don't find O2 sensors on cars that do not have to meet federal emmissions regulations (like the middle east). Our cars run just fine without oxygen sensors, and from a tuners perspective, usually better.
To kick your car to full open loop change all values in the Open Loop Enable Temp table to 300. To control vehicle fueling hook up a wideband and use the Injector Flow Rate table to dial in an a/f ratio of ~14:1.
Good Luck,
Kevin
05-09-2004, 01:32 PM
#12
NoGo-
I tried to do #3, Partial Open Loop. However scaling the lower rpm ranges in the PE vs RPM table has almost no effect on the idle AFR, even after I set TPS to WOT at 0 from 0-1200rpm. Any ideas? My idle is really rich (11.5:1) and I want it to be around 13:1.
I tried to do #3, Partial Open Loop. However scaling the lower rpm ranges in the PE vs RPM table has almost no effect on the idle AFR, even after I set TPS to WOT at 0 from 0-1200rpm. Any ideas? My idle is really rich (11.5:1) and I want it to be around 13:1.
05-11-2004, 11:58 PM
#14
WOW this is an old thread! I never saw that response from NoGo. That solution #3 sounds interesting, I think I may try that. There certainly is problems with using the VE table.
Sorry bomax, I'm no help . . . we'll just have to wait for NoGo on this one. How do you know your AFR is that? I don't think you can trust your O2 readings at idle.
Sorry bomax, I'm no help . . . we'll just have to wait for NoGo on this one. How do you know your AFR is that? I don't think you can trust your O2 readings at idle.
Last edited by Cal; 05-12-2004 at 12:07 AM.
05-12-2004, 12:31 AM
#20
Hmmm, maybe, but it was my understanding O2's simply did not light-up at idle. I know for sure this was the case before they started using O2's with heaters built in. I could be wrong, however; if an O2 sensor really can be used to tun idle AFR, that would be great. My wideband says 14.7 at idle all the time, and I KNOW that's not right. I'll be re-doing the Y pipe soon, so I'll find out if there was an exhaust leak.