Suddenly rich :(

tinygiants

tinygiants

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I have a roe with a VEC III controller.

Lately I have noticed that while ideling, it will occassionaly dip in idle speed for a second. It acts like it is about to choke off. I also noticed that at that moment it got suddenly rich. Second problem happens under throttle tip in. If I gently apply throttle, the first instant is a slight hessitation. Then as the throttle is applied more it acts normal.

I do not remember it doing this when I got the VEC installed. And I believe that the VEC does nothing to the signal under idle conditions. Is this two seperate issues? Could I be developing a bad O2 sensor causing the blip at idle (un-noticed when driving due to RPM). What does the throttle position sensor do for the way the engine runs? Would it affect throttle tip in? Could it affect idle (by definition - this makes no sense to me as the throttle is motionless at idle).

All of this became noticeable over the last month, but it was masked by a persistent tranny problem. The truck was eating govenor pressure swiches like candy (bad adjustment in tranny). Now that the tranny is sorted out, this problem is more evident.

TIA
 
tinygiants said:
I have a roe with a VEC III controller.

Lately I have noticed that while ideling, it will occassionaly dip in idle speed for a second. It acts like it is about to choke off. I also noticed that at that moment it got suddenly rich. Second problem happens under throttle tip in. If I gently apply throttle, the first instant is a slight hessitation. Then as the throttle is applied more it acts normal.

I do not remember it doing this when I got the VEC installed. And I believe that the VEC does nothing to the signal under idle conditions. Is this two seperate issues? Could I be developing a bad O2 sensor causing the blip at idle (un-noticed when driving due to RPM). What does the throttle position sensor do for the way the engine runs? Would it affect throttle tip in? Could it affect idle (by definition - this makes no sense to me as the throttle is motionless at idle).

All of this became noticeable over the last month, but it was masked by a persistent tranny problem. The truck was eating govenor pressure swiches like candy (bad adjustment in tranny). Now that the tranny is sorted out, this problem is more evident.

TIA
Click to expand...
mine stumbles a little bit too. figured it was in the tune. roe sets them rich. my tranny linkage needs adjusting also. who looked at your transmission for you. was it the dealer? im installing meth next week hoping that will help the richness. gonna have it dyno tuned here shortly also.
 
Mine does exactly the same thing. You can even smell the fuel at idle with the ac on if you do not have the recirculation on. I will be at Roe next week for fine tuning.
 
Could be TPS, or flaky (out of tolerance) O2 sensor....OEM's are known to have unreliable reference voltages. You can replace them with a Bosch part.

In regards to the VEC3 tune....if it just started doing this in the summer then the IAT settings may need to be tweaked.
 
my truck does it at start up, but once it's warmed up completely it runs great.

Also I have had the Vec III lose it's tune once, so I now plug in the card every time I drive it just for extra insurance!!:dontknow:
 
I want to further clarify. Mine only does that when it is cold. After warm up, it runs great.
 
Hi Everyone,
As you guys are describing this, I hear a couple different causes / scenarios.

1. We use a shorter reach and colder spark plug in the SC kit. These plugs are ideal for load / boost and work well when the motor is warm, but you do have to give them a half mile or so to warm up. You could use the stock hot / longer reach plugs, but that will NOT be the right plug for boost. When increasing the power output of an engine, you use colder plugs accordingly.

2. The VEC isn’t in the idle circuit and it’s completely controlled by the stock PCM. If the idle seems low or rougher than earlier in the year, this is probably the result of the lower timing advance the stock PCM uses as the air temperature is hotter. Dodge aggressively removes timing as the IAT increases. At an idle with a couple degrees less advance, the motor will run rougher. We can do something about this with the VEC though. We generally don’t mess with idle and low RPM timing, but we can advance it a couple (maybe 4) degrees to help smooth it.

2. The rich smelling exhaust (if occurring during closed loop conditions where the PCM is reading oxygen sensor voltage, adjusting the injector pulse, reading the voltage again, adjusting the pulse and so on to keep the target 14.7:1 AF in sight) could be either an O2 sensor, exhaust leak, using no ctas or the result of the decreased timing advance in hotter conditions (lighting the fuel later will leave more of it in the exhaust).

Speaking of how the OE ignition timing strategy is written as a relative to IAT, we just did a bunch of diagnostic work on a truck without a VEC or blower, but with a built motor, to see why it made less power than a completely stock truck. It took a while to diagnose, but a $1.00 resistor picked it up 80 RWHP.....
Let me know if I can assist any of you further.
Direct e-mail is the best way to reach me.

Regards,
Sean
[email protected]
 
Last edited:
what mine does is this. warmed up and at highway speeds. i try to ease into itand if i donw make it downshift out of overdrive it starts to load up and sputter pouring black smoke out the back. if i go on and get all the way in it and make it downshift it will do right. wondering if this was normal or needed tuning some more. ordered the meth injection kit friday should ship out today and ill have it installed by friday so we will see if that helps.
 
Do you have the VEC software? If so, log while driving the truck and trying to get it to have the problem and e-mail it to me. Sounds like I need to raise the voltage being output to the PCM on the Analog 2 circuit. We use that function to handle part throttle boost. One quick change should take care of it.
If yours needs an adjustment, it will be the second automatic (out of about 20 automatics we've supplied kits to) that I've seen react that way.
If you don't have the software, let me know what program cards you have, your name and we'll mail you a new card.
I'll take a look and see who we're sending out a WM card today and try to track you down that way also.
Regards,
Sean
 
i dont have the software. i do have a laptop dont know what all i need to do this. if you can tell me what all i need to do this ill get it done. the cards ive got are a 8 and a 5 talke dwith a guy at your place that said he would send the card for meth when he mailed out the kit to me
Eddie Whitehead. mailing it to 3265 s eufaula ave. Eufaula,AL. 36027 my cell is 334-695-1202 if you have any questions.
 
Sean Roe:rock: :rock: :rock: :rock: :rock: :rock: :rock: :rock:
 
I dont run a Roe,but I can say that past dealings with Sean,proved to me
that he is Always there for you when you need him!!!!!!!!!
There are some venders out that could learn from him!!!:rock: :rock:
 
Roe Racing said:
Hi Everyone,
As you guys are describing this, I hear a couple different causes / scenarios.

1. We use a shorter reach and colder spark plug in the SC kit. These plugs are ideal for load / boost and work well when the motor is warm, but you do have to give them a half mile or so to warm up. You could use the stock hot / longer reach plugs, but that will NOT be the right plug for boost. When increasing the power output of an engine, you use colder plugs accordingly.

2. The VEC isn’t in the idle circuit and it’s completely controlled by the stock PCM. If the idle seems low or rougher than earlier in the year, this is probably the result of the lower timing advance the stock PCM uses as the air temperature is hotter. Dodge aggressively removes timing as the IAT increases. At an idle with a couple degrees less advance, the motor will run rougher. We can do something about this with the VEC though. We generally don’t mess with idle and low RPM timing, but we can advance it a couple (maybe 4) degrees to help smooth it.

2. The rich smelling exhaust (if occurring during closed loop conditions where the PCM is reading oxygen sensor voltage, adjusting the injector pulse, reading the voltage again, adjusting the pulse and so on to keep the target 14.7:1 AF in sight) could be either an O2 sensor, exhaust leak, using no ctas or the result of the decreased timing advance in hotter conditions (lighting the fuel later will leave more of it in the exhaust).

Speaking of how the OE ignition timing strategy is written as a relative to IAT, we just did a bunch of diagnostic work on a truck without a VEC or blower, but with a built motor, to see why it made less power than a completely stock truck. It took a while to diagnose, but a $1.00 resistor picked it up 80 RWHP.....
Let me know if I can assist any of you further.
Direct e-mail is the best way to reach me.

Regards,
Sean
[email protected]
Click to expand...

This place rules........... You too, Sean.........

D
 
Prof said:
Sean Roe:rock: :rock: :rock: :rock: :rock: :rock: :rock: :rock:
Click to expand...
Admit it, it's really Amy you like ;) ;) :p :p :D :rock:
 
The whole crew is wonderful...Amy has a few characteristics that have some appeal that sets her apart...

Small town girl, cute, nice, about as tall as the fuel filler cap on a Viper. Truth be told, all women have redeeming values in my mind. I have never been one to cull.
 
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