10's at idle rich enough to smoke?
06-06-09, 11:29 PM
#1
10's at idle rich enough to smoke?
I have a light smoking problem at idle thats not affected by engine temp. It has a 500-700RPM surge and pulls 9s to 11s on the wideband mostly staying in the 10s. Its so light that I can't tell if its white or black...looks grayish. Fuel or oil/coolant?
06-07-09, 08:29 AM
#4
Yeah AFRS in the 10s and 9s will give the exhaust a tint if black for sure. I had to trim the fuel maps once I rewired my Walboro fuel pump, it was in the 10s at idle and reeked like gasoline.
Has your car always smoked a bit od did it just start? any recent fuel mods?
Has your car always smoked a bit od did it just start? any recent fuel mods?
06-07-09, 10:54 AM
#6
Recent fuel mod was the rewired FD pump with the resistor relay removed. I just got the car running after a rebuild though so it could be a lot of other things.
If I go anywhere near the exhaust it'll burn my eyes and I'll start coughing...lol. I thought that was expected with no emissions equipment though.
If I go anywhere near the exhaust it'll burn my eyes and I'll start coughing...lol. I thought that was expected with no emissions equipment though.
06-07-09, 11:46 AM
#7
Recent fuel mod was the rewired FD pump with the resistor relay removed. I just got the car running after a rebuild though so it could be a lot of other things.
If I go anywhere near the exhaust it'll burn my eyes and I'll start coughing...lol. I thought that was expected with no emissions equipment though.
If I go anywhere near the exhaust it'll burn my eyes and I'll start coughing...lol. I thought that was expected with no emissions equipment though.
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06-09-09, 07:15 PM
#13
10s under boost on a stock TII map is very rich too. With the stock S4 map, I was seeing AFRs around 11.5-12.0 at the richest. And under any load, the pump voltage would have been 12V with the resistor/relay still there, so that can't be to blame for this condition at least. You're running the stock FPR too, right?
06-09-09, 07:52 PM
#14
You were seeing those with the stock map/injectors and FD pump? Weird. I guess the fact that its a 6 port block changes everything. My understanding was the stock FPR being unable to bypass the increased fuel flow from the FD pump (+20psi IIRC) and resulting in pressure spikes. It becomes richer as the engine speed increases.
All I'm worried about is whether the AFRs are achieved at safe duty cycles. It boost creeps to 7-8 in 3rd gear although the AFRs are still in the 10s I'm not sure how hard the injectors are working. With the 6 ports and streetport I might be pushing my fuel setup.
If you don't have enough fuel will the ECU increase duty cycle to compensate (until you overheat and have a lean spike) or will you just have a lean mixture indicated by the wideband?
All I'm worried about is whether the AFRs are achieved at safe duty cycles. It boost creeps to 7-8 in 3rd gear although the AFRs are still in the 10s I'm not sure how hard the injectors are working. With the 6 ports and streetport I might be pushing my fuel setup.
If you don't have enough fuel will the ECU increase duty cycle to compensate (until you overheat and have a lean spike) or will you just have a lean mixture indicated by the wideband?
06-09-09, 08:39 PM
#15
The FD pump doesn't overwhelm the FPR. I tested it recently, and had 34 psi at idle, 41 at 0 manifold pressure, and 51 psi with 10psi of air pumped into the FPR line. That's roughly stock pressure all around. Now with a walbro, I had about 40 psi at idle, and it ran like ****.
The ECU has no way of knowing if you're getting enough fuel, so if your system can't supply enough, you'll just run lean. Duty cycles only increase with airflow and boost, as the map specifies. And the cap on the stock ECU should be 80% D/C.
The ECU has no way of knowing if you're getting enough fuel, so if your system can't supply enough, you'll just run lean. Duty cycles only increase with airflow and boost, as the map specifies. And the cap on the stock ECU should be 80% D/C.
06-10-09, 07:52 PM
#20
For some reason when I tested my fuel pressure with the pump on and key ON it shot up to 40psi as soon as I turned the key. I did it to confirm since I had 0psi before because of an O ring restricting the fuel pump inlet. I'll have to wait for the RTEK 2.0 to come out for the S5 TII.
06-10-09, 08:13 PM
#21
Sounds like rotaryrocket might have more info on this than me. I was thinking the FD pump would increase the pressure in a similar fashion the the walbro. You might just have to deal with it for now. I know you'll like the Rtek 2.1 once you get it, you can even watch the duty cycles of your injectors.
06-10-09, 10:52 PM
#22
For some reason when I tested my fuel pressure with the pump on and key ON it shot up to 40psi as soon as I turned the key. I did it to confirm since I had 0psi before because of an O ring restricting the fuel pump inlet. I'll have to wait for the RTEK 2.0 to come out for the S5 TII.
06-18-09, 08:33 PM
#23
Yeah, duh. 
So I did some "logging" today, it looks the the map has a lean spot. Redlining first gear the AFRs are OK but as soon as I shift into 2nd gear, from ~5k-6kRPM the AFRs stay in the mid 12s even though its at full boost (5psi).
Is this lean condition enough to do any damage? What are your AFRs like in the described condition?
So I did some "logging" today, it looks the the map has a lean spot. Redlining first gear the AFRs are OK but as soon as I shift into 2nd gear, from ~5k-6kRPM the AFRs stay in the mid 12s even though its at full boost (5psi).
Is this lean condition enough to do any damage? What are your AFRs like in the described condition?
06-19-09, 10:01 AM
#24
Mid 12s should be fine for low boost around 5 psi. Or at least it is with lower compression rotors.
It's hard for me to say exactly what AFRs I show at 5 psi in the upper RPM range, since I normally see around 10 psi in the 5-6k range at WOT. I can only build 5psi, if I'm at partial throttle. I would expect it to be in the 12s though. I'll post an Rtek log tomorrow (when I'm home again), so you can see the numbers throughout the range. I've been targeting 11.5 AFR with my adjustments.
It's hard for me to say exactly what AFRs I show at 5 psi in the upper RPM range, since I normally see around 10 psi in the 5-6k range at WOT. I can only build 5psi, if I'm at partial throttle. I would expect it to be in the 12s though. I'll post an Rtek log tomorrow (when I'm home again), so you can see the numbers throughout the range. I've been targeting 11.5 AFR with my adjustments.