TrackRunner

Hey all. I've been tuning my 4Runner and noticed that during WOT runs, my ECU will stay in closed loop all the way through 1st, 2nd, and 3rd gear. The TPS looked fine when hooked up to an Ohm meter. When the throttle was wide open the voltage was about 3.2. I have replaced the plugs, wires, front 02, and cleaned the TB. Any suggestions on what to do next?

rimpainter.com

It would help to know your mods.

What do you mean by "tuning" it? Are you running a piggyback?

TrackRunner

Sorry, I thought I had it in my sig

I have a 2000 4Runner SR5 with the TRD supercharger, URD Fuel Upgrade Kit, and a 2.2" pulley. I am tuning the FTC-1.

Greedy

What scan tool are you using to monitor open/closed loop operation??

TrackRunner

The BR-3 Scan tool.

Greedy

The screen that shows all you diagnostic data (rpm, load, temp, timing, fuel trims, open/closed loop) has buttons next to the numeric value. When you click on that button, it updates the value in the cell. You can also get it to auto update while you are driving. You can tell it is doing this as the cursor "flashes" on each button successivley and updates the values. However, it does not update the closed loop/open loop operation for some reason. Try hooking up your scan tool, flooring it, and then click on the button closest to the open/closed loop display area. It should update to show that you are in open loop. Once you get off the gas, click it again and it should show closed loop again.

mt_goat

Your's doesn't? Mine does What about the fuel trims, does it update those? If so, you should be able to tell when it goes into open loop when the trims go to zero.

mt_goat

You might try updating your BR3 software, they have new versions available from time to time.

Greedy

Looks like it! Yeah, I have always wondered why it would update all the cells except for that one. I will go to thier site and check it out. Thanks!

mt_goat

Yeah here's the lastest, v 4.1:
http://www.obddiagnostics.com/ProgWin.html

TrackRunner

When I floor it and monitor my fuel trims, they continue to change throughout the rev band (never going to zero). My LM-1 reports 14.7 AFR the entire time as well.

Also, I've noticed almost all of my fuel cells in the vacuum region of my fuel map are around 9.9, and in the 10+'s for the boosted portion. I'm not sure how out of the ordinary that is, but it seems like I should be running rich. Anyone else have 10's in the boosted portion of the your map?

Thank you for the help.

mt_goat

Wow, that's strange What URD kit do you have?

TRDatVT

When your O2 final ☺☺☺☺s the bed and doesnt work anymore, your computer is forced to stay in open loop and use only the MAF to tune (check engine light is lit)... I can only assume that if there was bad readings from the MAF that it might be resillient to enter open loop and is trying to tune more based on the O2 readings... is your front a wide-band or standard 0-1V o2 sensor?

TrackRunner

Dale: I have the 6 larger injectors fuel kit.

TRDatVT: I have the 0-1V O2 sensor in front.

mt_goat

It sounds like he's stuck in closed loop, but I'm clueless as to what would cause that, unless it's a bad ECU. Are you getting the throttle plate to open all the way?

By the way, my FTC came pretuned with the higher boost regions at 10 or very close to 10 (like 9.9) and I ran too rich with it like that, like about 9-10 A/F ratio at WOT (open loop of course).

mt_goat

Oh... I see what you're saying now.

shabbo

I have similar issues on my 2001 4runner with the URD 255 walbro pump and the 315 injectors.

The URD FTC solved the ping problem. with the preconfigured trim table all my pre-boost cells were around 9.9 and the boost cells were 10. I know for sure that I was running too rich and I had to bring the boost cells down to a smoothed 9.6 average. Any more would turn on the Check Engine light. but its better as long as I don't WOT.

But anyways, it's running too rich even with my 2.0 inch pully and 11 PSI air. on WOT I lose power and engine has pulsing surges and my Air/Fuel meter is showing very rich. Spark plugs get carbonized too.

I'm thinking about installing a Vortech Super FMU to reduce the fuel supply pressure and smooth the output and give more room for the ECU to play. What do you suggest?

mt_goat

Interesting... are you running WI?

shabbo

I have the 7th injector installed but have not connected it to anything since the whole system runs rich over 75% throttle. However with the TRD headers and exhaust with Over-drive off there's lots of power over in the 75mph-120mph band, it's a screamer when overtaking.

I disconnected the TRD aux ECU as the URD FTC seems better tuned.

Trouble is that I have to gradually ease into WOT else the system gets confused. I don't know exactly what's going on except that my A/F meter reads very rich as I approach WOT.

I have the Level 10 hydrosystem upgrade which feels tight and accurate. This helps the ECU since the gears shift precisely in tune to the power and manifold pressure changes.

I'm keeping this smog test proof so I'm not using any alternate fuel injection.

my last resort is to use a tunable FMU to reduce fuel pressure to allow better ECU calibration. I can then also incorporate the existing 7th injector to pulse more fuel with the intercooling effect in demanding areas for more power.

In my sleep I'm dreaming of bizzare ways to a achieve a perfectly tuned state!! it's bugging me If this was a Supra they'd be so many options to work with. But I love the 5VZFE!

mt_goat

Like how rich is very rich?

So there is no fuel going through the 7th inj at all?

Yeah that would be an interesting test, did you by any chance run bigger wires to your fuel pump? That is a large fuel pump, I'm running too rich in open loop too and I only have the Walbro 190 and 318 cc injectors. I've tried dropping my FTC fuel map values down from 9.9 all the way down to 8.9 with some improvement, but still a little too rich at WOT (A/F around low 10s, sometimes I see a 9.x pop up)