Long time to spool,Can't get WB/O2 to match A/R

UR50SLO

The Reaper
Joined
Jun 12, 2001
Lance or anyone who can help. We are trying to tune this car for the first time. We have a problem with long spool up time and the Wide band won't match what is on the A/R table.
For example: anything above 2500rpm is set at 11.8 a/r
When we data record it says that actual a/r is 12.5
Timing we set at 19.5 anything above 3500 that works fine
Drivability just crusing around is very excellent. good throttle responce after playing with the tps/map adjusments.

Seems like the motor is not quite winding up as fast as normal.
We've only put 16lb boost to it. No popping/weird stuff.. clean passses. Any help with suggestions on how to get the actual to match what's on the a/r table and spool up time would be great!

86 Camaro. 237Cid buick, GN1 heads,.72mmPTE,THDP,Precision's Camshaft(non roller)CAS front mount,ACufb.70throttle body) Art car 3500stall and preped trans(200r) 9"Ford/3:89gears) approx 3200lbs.
 
Well my slow 5.0 has no problems spooling so I may not be much help. But have you changed any VE values to get closer to target a/f? Closed loop is on at those lower rpms?
 
A/R ratio

By spooling I mean it's just not as responcive as I had hoped with a 3500stall. Maby I need to adjust my timing to make the motor more responcive? The wideband should start making corrections in closed loop at anything over..humm... I think I just talked my self through what I might be doing wrong. Closed loop low should be where it"stops" being in closed loop or the TOP of the rpm scale. Closed limit high states it should be the place where closed loop STARTS. humm.. I'll change the Closed loop loop Low to 7500rpm... seems backwards to me.
About spool time.. Any suggestions? anyone? Thanks~Scott.
 
Mine is something like this:

Closed Loop High ~ 500 rpm
Closed Loop Low ~ 450 rpm

Art

9.61 / 141.9
 
DOh.. looked at the book..

Yep.. Your right.. boy is this manual a little on the confusing side.
I have the HI limit at 1400rpm and the low at 1300rpm. Idle is great. NOW, having that figured out and said. The VE table, what numbers have worked for you.. We had set them up at the low 100's but working down to the 95 range... the lower we go the faster the car seems to go. Why in the hell are we not getting any o2 correction? I mean that line when we data log is a flat liner! but we are not meeting our target A/F ratio at 11.8 its 12.5(actual) Any Ideas> Thanks again for your help. New to system.. don't want to hurt the Engine.~Scott:eek:
 
The VE numbers should be adjusted so that the target a/f matches the actual a/f ratio... there are no "right" or "wrong" numbers. In closed loop terms, set the VE numbers so that the correction is as close to zero as you can get it.

Check the following things to figure out why closed loop isn't happening for you:

1. HI and LOW RPM settings as discussed above.

2. Minimum temp for closed loop operation.

3. Make sure the "Closed Loop Enable" check box IS checked.

4. And now for the undocumented part... closed loop won't happen until all after start fuel enrichment is gone. Look at one of the after start screens while the car is running and make sure that the "Aft. Correction" sensor works its way down to zero after a little bit. It is possible that the after start decay rate could be set so that it takes FOREVER to decay all the after start fuel out, and closed loop is but a distant dream. :(

If the O2 sensor is displaying a/f ratios, everything is fine. It is not possible for a system to correctly display an a/f ratio but not be able to go into closed loop.

The after start fuel settings in the demo calibration file on your C-Com disk should be a good model for you to use in your own calibration.

Craig
 
Guessing it's the Wide band.

:rolleyes: Well.. We ended up going to the track on friday.
Made one pass. From the data log, the most TPS% was 43%.
Paul(owner) was at 94% for the part where he was staged to leave then it went right back down to 43-39% the rest of the pass. The car went a 12.5@110mph with under half throttle. He said the trans was acting strange so he just crused down the track the rest of the way after launching. We got it back to the shop where I went out for a solo pass with the car on the street. The 200R is totaly dependent on the TV cable for shift points and firmness like the 700r is. It was shifting late and hard. We've backed it off but still seems to have a long late shift. It hit the rev limiter at 6500rpm when I drove it on the first pass, On the second pass it stayed below 6500 and kept right on motivating. I don't think from the o2 numbers we are getting on the(actual A/R) that it's anywhere near correct after making a few trips down the road. This is a new sensor that came with a complete setup from Precision.. is there any warranty on widebands? we have never had a correction% Since startup. less than 150mi on entire setup. :confused: I'll check the O2 as per Craig voltage before assuming it's the WB sensor.. thanks again guys, Scott~
 
UEGOS numbers

:( I think we found a problem houston.

The UEGOS (there are two readings)
one reads in red .96-.92V

The other reads 3.14-3.40 V

What do you think we should do now?
Craig said that the sensor should read .45 no higher or lower.
I'll Mail you directly too Craig/Lance. Thanks, Scott
 
Are those V readings from the O2? There are 2 seperate readings from the O2? How do you check that? Need to be under load or just have the motor running? I assume your reading tell you that you have an O2 problem? Thanks.
BTW, do you use a trans brake? What is your luanch rpm? I have a 5500 converter in mine, I'm gonna take it out cause I think it's too much with my T76. I'm thinking 4000-4500 for me, I'd guess you'd need around 4000 or so, but keep in mind I am NO expert :D
 
U numbers

Lance and Craig said that the UEGOS numbers on a speed pro system are indicators of how the Wide Band O2 Sensor is doing. Normal perameters are.45V or so. We have a reading of .96volts.

The Heating element in the O2 works fine. It's somthing else in the sensor. We also checked the sensor unpluged and had a reading of 1.02V. I guess that means the ECM is ok. We are probably going to send the Sensor in for testing/replacement because it's new.

We have a 3,500stall in the car. It's realy not bad spool time just not quite as responcive as I'd hoped...
Take care, Scott~
 
O2 Fixed!

:D Well.. New O2 is in and working great..... The closer we make the A/F map to the O2 correction the better the car runs.

Question on Down pipes... Anyone had a larger DP work MUCH better with large turbos like the PTE.72mm? Just wondering ..
Thanks again for all your help everyone!~Scott
 
Top