SARX7

I'm looking at all the maps again and most all of them seem to have 121 for the values in the N02/P05-PO7 cells.

With my car setup like this I cannot get it to idle correctly anymore. Tthe idle is lumpy and it smells very rich, but the O2 readings never go past .80 (usually .74). I've pulled a lot of fuel out of these cells as well as N03/PO5-PO7 and now they are all down to the 100-101 range and the idle has improved greatly, and the O2 voltage hovers around .74-.82 range. I've tried to reset the values to 121 and then pull the battery cable and let the car "re-learn" it's idle but the idle remains lumpy even after sitting for ~40min.
The only thing that cures it is to remove fuel from these map points.

This all started when put my freshend motor in with its new 1300 secondaries and brand new O2 sensor. When I fired it up and the idle settled down it was really lumpy and the O2 readings were around the .89-.92 range. I pulled a lot of fuel out and to the aformentioned cells down to the 100 range and the idle was rock solid, but O2 readings were not, they fluctuated between .64-.82 (more bias towards .74-.80).

So I've been trying to track down why the O2 readings are so wierd and the idle changed so greatly with the addition of larger injectors that shouldn't even affect the idle.


What is everyones opinion on the O2 feedback and idle ignition control?

I've noticed that my leading and trailing ignition settings are pretty much ignored at idle and the computer hunts around a lot, and that the O2 readings will slowly fall while I have the offending cells set to 121. they have gone down to as low as .5 and hover there for a while, it never goes up though. I usually kill the car and reset all the values a bit lower and try again. It seems to me that the car is pulling fuel out to compensate for the rough idle, but that doesn't seem to solve anything.


I'm at a loss here since the engine isn't broken in yet I can't take it to a dyno and run through the normal tuning process, so I'm doing this all in the meantime.


Any sugestions?




Also of further note acording to Wayne at RC engineering there shouldn't be much of a difference between a 850cc and a 1300cc injector as far a lag time is concerned, but he does recomend between .1 - .2 lag time setting to be used as a precaution.

cewrx7r1

iTrader: (2)

New motor and PFC changes, thus the chance for many things to go wrong. Since the O2 has an output, I doubt it is the problem.

Even though I have an air pump, if I disconnect it; my engine still idles very smooth but with a .8v O2 output.

Check the PFC setup where you enter the injector size and correction factors and post it here.

SARX7

Injector Data


Front Primary 100% +0.00ms
Front Secondary +0.20ms
Rear Primary 100% +0.00ms
Rear Secondary +0.20ms

Q - Pr 550cc
Q - Sc 1300cc


I have no airpump or any other emmisions equipment for that matter.

The only changes made to the PFC prior to me messing with the fuel map was to set the injector size in the PFC. Then when I started it up and let it learn the idle I had to pull out fuel. I did it first by changing the 1000 RPM PIM value to 70%, then when I found that worked I worked on the individual cells (all before driving the car). The PIM is now back to 100% and the cells are set to ~101.

cewrx7r1

iTrader: (2)

Your injector data is good!

My friend Kyle had a similar problem with his large port single turbo engine. He had to play around with it like you but he did finally get it to idle correctly. I think he had to adjust his TPS voltages a little higher even though they were in the standard limits. The porting had changed the idle requirements such that the TPS was not in-sync with reality anymore.

Check your TPS voltages with the PFC and try upping them a little.
I found that removing the air hose to the primary injector air bleed pipe
degrades the idle also. If yours is removed or plugged, connect it back up.

SARX7

Hmm good idea, I'lll check all that.

Where do you adjust the TPS voltages in the PFC, is that the PIM options or the PIM % adjustments.

I'm also going to check the wiring for my O2 sensor, I noticed last night that my PFC displays higher than my autometer gauge. I've also noticed that the car never goes into closed loop durring cruising.

cewrx7r1

iTrader: (2)

The TPS voltages only can be read on the ETC function page. The TPS has to be physically moved to change the voltage.

SARX7

Ah gotcha that makes sense then.

cewrx7r1

iTrader: (2)

I gave the wrong screen. It is the ETC sensor screen.

SARX7

Yup, I can't belive I didn't think about that.
I'm going ot to check it now.

Wargasm

I just got my car fired up with these mods:

Rebuilt the engine
My own street port setup
T04S (XS Eng Kit)
PFC
Full exhaust
No emissions ****
850 cc primary, 1300 cc secondary

And the idle REALLY sucked bad the first time I started it. If I held it at 1000 RPM it smoothed out a lot.

I let it run for about 20 min... Then I had to mess with some stuff so I ended up killing the power and starting over.

Idle was still not good, but much much better. I'm going to try fiddling with some of the things mentioned in here to see about fixing that.

My only concern is that if I suddenly open the throttle (with load or even in neutral), the car hesitates pretty badly sometimes. Could this be fixed with the "injector lag time" or something?

Brian

87 TII
93 R1

7-sins

When was the last time you replaced your plugs? I did the PFC & Full Exhaust not too long ago. Since I have had a idle that likes to stall on me, it starts to stumble above 6k, and likes to blow out black smoke. I am hoping new plugs & wires will fix this.

SARX7

My TPS was ust barely out of spec, when the car was idling the TPS was telling the computer that the throttle was completely closed.

I adjusted the TPS to be right on the edge between fully closed and partially open and this solved a lot of hesitation on jerky acceleration since I don't have an air pump.

I also removed a lot of fuel from the idle area of my map also since I don't have an air pump.

I've come to the conclusion that my O2 sensor is bad since I can add in 149.6% more fuel at any RPM point using the PIM Voltage menu and the sensor won't read past ~.76v. Its really rather annoying.

suganuma

would these lag time values also be somewhat accurate for the 1200cc injectors?? i would assume so - but it never hurts to check...

thanks,

cewrx7r1

iTrader: (2)

Someone had posted .10 to .20 lag for 1300s.
Ray put .04 in a friends PFC for 850s bored to 1200s.

Try different settings with short boost runs. It will affect smoothness if too far off. Do not try this way off test at high boost and high rpms. If way off(roughness), it will cause puddling of fuel in the intake and rotor chambers and thus will not evaporate completely. Might cause a lean burn(booom!).

You can see this roughness at idle by adjusting the primaries way off.

I have tried both .04 and .10 with my 1200s with no noticeably differences.

suganuma

thanks chuck,

anyone else have anything to add??

SARX7

I was the one who posted about the 1300's being between .1-.2 ms, I got this info from RC Engineering.

The guy I talked to, Wayne, said with that large of an injector the difference between .1-.2 is miniscule.