Installed Digital WUR - AFR problem

[930_noob]

Hello fellow Pelicans! I am a new member of the Pelican forum. My mechanic just installed a UTCIS-PT digital WUR last weekend and I am still tuning it with my car 87 930. I used the base map of the new digital WUR. It was OK on the warm up cycle wherein my car started and idled good. After the warm up cycle is done, I see that my AFR is a rich at 13.2-13.5 and I am reading my computer (UTCIS software) that the manifold pressure is 0.9, current pressure is 3.0, target pressure is 3.0. After a couple of minutes, my AFR is getting richer and richer. It started from 13.2-13.5 gradually going down to 10.1-10.2 which looks like the engine will die. I adjusted the fuel mixture in the fuel distributor and leaned it until I get 14.2-14.7 AFR. Now the engine is running better. I tried to run the car and pulls ok, but as soon as I reached the stoplight, my AFR was getting rich again down to 9.9-10.2. The car ran terrible. I stopped for a few minutes and started the car again, now the AFR is a little lean 15.2-15.7. I went back home to adjust my digital WUR on the idle side. Going back home, the AFR on idle is between 15.2-15.7, manifold pressure of 0.9, current control pressure is 3.0 and target control pressure is 3.0 at 1000rpm. I adjusted the control pressure on 0.9 bar (manifold pressure) from 3.0 to 2.6 and now my AFR is 14.2-14.7 which I wanted on idle. I turned off the car. After 10 minutes I started it again, it’s back again to being rich from 12.9-13.2. Then Adjusted the control pressure form 2.6 back to 3.0 again getting my desired AFR 14.2-14.7. Then after a few minutes, it would go very rich to 9.9.-10.2 which the engine is about to die again. It’s been going like this back and forth. I just don’t why that it would sometimes go very rich on idle that the engine is about to die. This was not happening when the stock WUR was on. I hope you could help me with this problem on what to do. I don’t know if it is a fuel distributor problem, injector problem or the digital WUR not tuned correctly. I hope you could advise me on this problem.

[964 T #304]

You need to ck. and see if you have a good hot wire going to the harness that plugs into the wur. If you loose power to it it will go into a fat mode like you are saying 9-10 or so on the afr. If you unplud the power to the utcis and asart it you will see what I mean . It will be hard to start because it will be so rich . If you have an intermitten power failure to it, it will fluctuate like that. That could have contributed to your problem with the stock wur. If that is of no help I would call Steve and ask his advice as he is a car guy himself and can probably point you in the right direction .Good luck,when you get it lined out you will love it.

[mark houghton]

I have no experience with the digital WURs, but assuming it's installed and programmed correctly, perhaps there are other areas you should investigate which might cause the same problems you're experiencing regardless of the type of WUR you're using.

One thing comes to mind: Are you still running with all your emmissions stuff connected...specifically the Lambda controls (O2 sensor and the frequency valve it controls)? May be a malfunction there somewhere. Logic would tell you to suspect the newest addition (the WUR), but don't ignore other potential causes. Just my 2 cents....

[930_noob]

Thank you 964 T and Mark for the advises. After I got home, I tried to start the car again. It was reading 14.7 on the warm up cycle, then going down to 14.2. After maybe 5 minutes, it went up to 15.7-15.9. It didn't become so rich like 9-10 like last night. I don't know if it is the intermittent power failure because last night, while the AFR was going down from 13.5 to 10, the display on the UTCIS software did not change values nor did not flicker if there was intermittent power failure. But I 'm not sure.
Since I was reading a little leaner a while ago, I remembered what Mark said to check all other stuff like O2 Sensor, I unplugged the stock oxygen sensor and the AFR went rich like 12.8-13. I adjusted the fuel distributor and got the 14.2-14.5. The AFR became stable even after 5-10 minutes. I ran the car on boost and the car pulled stronger than last night. I just need some more adjustment on the MAP on my digital WUR coz I am running rich on boost like 10.4. Went back home and let the car rest for 10 minutes. I started the car again and the AFR was 14.3-14.7 and a couple of minutes later settled to 14.2-14.3.
I would say the car ran better and more stable with the stock oxygen sensor unplugged. Will it be better this way unplugged or will it do bad effect to the car's performance in the long run?

What would be the normal AFR if you are cruising in the 2nd gear on 3000 rpm and 40 mph? My AFR is 13.6. Is this lean or rich?

Thank you again for all the help!

[mark houghton]

Originally Posted by 930_noob

I would say the car ran better and more stable with the stock oxygen sensor unplugged. Will it be better this way unplugged or will it do bad effect to the car's performance in the long run?

What would be the normal AFR if you are cruising in the 2nd gear on 3000 rpm and 40 mph? My AFR is 13.6. Is this lean or rich?

I haven't run with my O2 sensor since the day I bought the car, unplugged it and tuned around it. It's primary purpose is to keep emmissions in line to keep the feds happy. Running without will allow you to tune to the best AFR for your particular engine by taking one more thing out of the loop that constantly wants to adjust your mixture for you. The only issue might be if you live in an area that requires emissions testing, in which case you might have a problem passing as your idle CO would probably be too high without the Lambda system leaning things out for you.

AFR's at 3000 rpm/2nd gear is kinda up for grabs, depending on you car and current mods. Ideal from an emmissions and complete fuel burning standpoint is 14.7, but many people find that to be too lean. I have mine set to where at idle I'm at around 14.2 fully warmed up, and about 13.8-14.0 at cruise. Your 13.6 should not be a concern if the car likes it there.

[9dreizig]

930,, it would help if we knew your year and mods of your car.
13's are a little rich at no boost and cruise in my opinion
Where are you located ??

[JBL930]

Originally Posted by tj930

Since I've just been suffering these problems myself, I think I know what's wrong with your Mapping!

I'll email you.

Tom, copy your email on here mate so everyone can see. Or failing that send me an email as well, i'm morbidly curious.... Oh, i may actually be buying one to stick on my 930 engine at some point so that's good enough reason

[911st]

Is your vacuum at idle correct and is your D-WUR vac/boost tube hooked up correctly?

Check your car for proper vac at idle (leaks). If you are not maintaining a proper vacuum level the D-WUR will think you are accelerating.

The D-WUR only knows you are accelerating or from the Vac/boost signal it receives. I takes intake maniflod pressure and the RPM to determine how much to adjust control pressure and thus your AFR. If it is not getting the right signal, it can not work as intended.

I would suspect that at idle you want to be around 14.5-15/1 AFR.

With accel off idle go instantly to about 13-13.2/1 (max pre boost TQ) and then start to become richer as boost starts to build.

Than at cruse go back to about 14.5/1.

It could also be that you are not getting any signal to the MAP circuit at all as if the vac line is not hooked up. In this case it will think you are accelerating at all times but not to the point where it is getting boost and thus run lean on boost.

Lastly, if the D-WUR vac/boost line is hooked up to the wrong place, it could get really wacky as many of the ports off the throttle body are ported and the signal changes at different throttle angle .


Just a thought.

[930_noob]

Thanks for ALL the replies and all the suggestions!

I am running a lot better now with a little adjustment on the MAP but still a little rich 13.3-13.8on cruise. On idle, it's 14.2-14.7.
Just need more tweaking on the MAP. I haven't tried my AFR's yet on boost on my new MAP. I tried to call Unwired Tools several times already but no call back.
I think it would be better to post some screen pics here of the MAP and some AFR, boost and RPM pics so you could help me fine tune the digital WUR.


Last night, I tried to hook up again the stock oxygen sensor, still good afr's on idle. I tried to run the car and after a couple of minutes, then the AFR's went down to 9.5-10. I pulled over and unhook the stock oxygen sensor and went back to normal. It is acting up when the stock O2 sensor is on. The O2 sensor is only 6 months old.

911st, it's my mechanic who did the install. I can see that there is a T-connector wherein 1 hose (black) comes from the digi WUR, the orange hose was cut and the ends were plugged into the two ends of the T connector. I'll take some pics later and post it here to verify if it was done correctly. On idle, UTCIS software is displaying these data:

Current Control Pressure: 3.5
Target Control Pressure: 3.5
Manifold Air Pressure: 0.9
RPM: 1000

My AFR is reading 14.2-14.7

930dreizig and TJ930, my car is an 87 930 with minor mods like K27s, Tial Wastegate with 1 bar spring, Fabspeed dual exhaust and Evo air intake. I am from North Las Vegas.

TJ930, thanks for the email. I'll send you my current MAP later. It's running better now but still a little rich off idle and cruise. By the way, the green wire is not connected to the O2 sensor.

Thanks again!

[WERK I]

I do not recommend having the stock 930 lambda system running simultaneously with the DWUR. What you have is two systems with different mapping attempting to adjust lambda at idle at the same time. My $0.02, can the narrow-band O2 sensor and put in a wide-band to tune, remove the WB sensor, plug the bung and enjoy!

[964 T #304]

Where and with what are you getting your readings for afr,tail pipe or welded in Bung. Just wonder if you could be getting false readings.

[964 T #304]

This might help for a starting point . It works on mine ,but I have a Turbonetics turbo that might flow more @ idle also,don't know but it gives me an adv. AFR of about 14.50-14.80 @ 900-1000 rpm. I have the early mod. with 1/2 as many set points as the latest version ,but it should work for either. On the map .4-2.8, .5-2.9 ,.6-2.9 ,.7-2.9 ,.8-3.0 ,.9-3.0.

[930_noob]

964T#304,

The bung is welded in the tail pipe where the wideband O2 is placed. I am using Zeitronix for my wideband controller. I read that some had problems with O2 placed in between the turbo and muffler due to excessive heat that is why I opted to place it in the tail pipe. Will it be higher AFR if placed in the tail pipe compared to placed in between the turbo and muffler?

[930_noob]

911st,
this is the picture of the hoses. It's hard to take pictures in there. I hope you can figure it out. Label #3 is the hose from the UTCIS, #1 goes to the manifold and #2 goes in behind and under the Fuel head but don't know where it is connected.
Did my mechanic do it right?

[JBL930]

Don't understand why that would be "T"'d to anything? Unless it runs to a boost gauge in the car?

[930_noob]

I read this from Unwired Tools website and I conclude that 911st analysis is the most logical to what is happening to my car.

This is for the UTCIS-V but probably applicable to UTCIS-PT
http://unwiredtools.com/manuals/UTCIS_Application_Guide_A2.pdf
pages 8-11

The correct manifold pressure for the digiWUR should be 0.4-0.5 bar at idle and mine is 0.9 bar at idle. It says that if it is 0.6 and greater, it could have a weak vacuum or could be what they call "performance camshafts."

When I put a small load on the engine, the manifold pressure should go up from 0.4 to 0.6 or0.7. With mine, it is the other way around from 0.9 down to 0.6 or 0.7 then goes back again to 0.9 on idle. This is probably the reason why I am always on the rich side eventhough my control pressure is on 3.8 already.

911st, basing on the picture I posted, do you think it is hooked up correctly? Or is there a better vaccum line for the digiWUR to be hooked up?

[beepbeep]

Originally Posted by 930_noob

I
The correct manifold pressure for the digiWUR should be 0.4-0.5 bar at idle and mine is 0.9 bar at idle. It says that if it is 0.6 and greater, it could have a weak vacuum or could be what they call "performance camshafts."

When I put a small load on the engine, the manifold pressure should go up from 0.4 to 0.6 or0.7. With mine, it is the other way around from 0.9 down to 0.6 or 0.7 then goes back again to 0.9 on idle. This is probably the reason why I am always on the rich side eventhough my control pressure is on 3.8 already.

911st, basing on the picture I posted, do you think it is hooked up correctly? Or is there a better vaccum line for the digiWUR to be hooked up?

You did connect boost signal line after the throttle, did you? Otherwise, you will never get the vacuum. If you pick signal between filter and throttle, you will never get vacuum and your gadget will believe you are always running on medium-load throttle.

[964 T #304]

If you have the bung welded to close to the end of the tail pipe you will have air sucked back in tail pipe @ idle and get all kind of false readings. I have a NGK wide band o2 sensor and meter and in thier directions they say to install the bung 10 dia. of the size of the exhaust from the end ie." 3" exhaust =30 in." from end. Most folks say to mount it at about 6" from exhaust outlet of the turbo. I don't know what is best but mine works fine. I have 14.50-14.80 on idle. and with it set at about that it elimated the lean popping on deacceleration. Good luck

[930_noob]

Beepbeep,
honestly I don't know. It's my mechanic who did the install. Based on the picture, the #1 hose is connected directly from the Manifold and #2 hose goes behind the Fuel Head but a little further (throttle ???). Is this a correct install? If not, where can I see the right vacuum hose?
And I see another hose (same kind of hose but longer) from behind the fuel head going to the front (vacuum filter??).

964T#304, my O2 sensor is bosch same sensor innovate is using, and says that it should be placed 6 inches after the turbo before the muffler but that specific space is only like 3 inches that is why some including me did not put it there due to excessive heat being so close to the turbo. I put the sensor right after the muffler and about 6-7 inches before the tip. Hopefully I am getting quite accurate readings.

[WERK I]

Originally Posted by tj930

You know, I feel well within my rights to be p!ssed off with your behaviour, Arlon!

There's only 1 other person on here with (a) a pre-1989 3.3 930, and (b) a Mk2 UTCIS DWUR - and he ASKED YOU POLITELY to email him... But, oh no, can't do that!..Far too easy!.. Let's solicit the opinions and conjecture of those who have similar equipment (but not the same) and may not quite know what they're talking about... Let's get this simple thread to run now into 21 replies and 2 pages!.. Let's mimic the other, over-long DWUR thread (which has now stretched into something like its 37th page! ).

First off, who the %$@# is Arlon?! What is the point of having a forum where information (good or bad) is free for the taking if is nothing more than posters exchanging emails to get info? You mention that in the future someone may want to use this topic for reference. Are you available to answer every email that may come your way on the subject for the next umpteen years?

You're complaining about two pages of posts? Good grief, I've seen more than that concerning Porsche's placement of the ignition switch.