Welcome Guest [Log In] [Register]
Posted ImageWelcome to the all new Geo Metro Forum. We hope you enjoy your visit.

You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are features you can't use and images you can't see. Registration is simple, fast, and completely free. If you're already a member please log in to your account to access all of our features:

Join our community!




Username:   Password:
Add Reply
code 13 (O2) and WOT stumble at altitude; trying to figure this one out - SOLVED
Topic Started: Feb 17 2013, 06:53 PM (1,554 Views)
rjsdotorg
Member Avatar
R E Member

Took a drive today to over 6,000' (from 4k) for the first time in the Metro. Steep mountain road, spent a lot of time at WOT in 3rd, 30 seconds or more at times. Recall that I have the Spectrum air cleaner, with hot idle air and cold ram air from the bumper otherwise. I also don't have a WOT switch at the pedal, but I thought that was only for A/C cut-out.
Temps were ~50F.
Somewhere over 5000' the CEL comes on - I stop in a bit and pop in the CEL fuse; code 13. I drive up to 6100 at the top, and notice along the way that WOT is actually putting out less power than 80-90% throttle. When I let off the pedal 1/2" reasonable power resumes; floor at 6000' and it actually stumbles.
Stopped at the top, reset the codes, removed the IAT resistor and put the ERG modulator back in the loop. Still stumbled at brief WOT testing, but no codes on the way down - which is mostly engine braking.
Back at 4000' I tried some WOT runs; I noticed that there isn't much difference in power at the last 1/2" of pedal, but no actual stumble, just kind of flat power curve there.

From the FSM: "After the sensor is hot, if the voltage stays above 450 mV for rnore than 10 seconds, this indicates a rich condition. If voltage remains below 450 mV for more than 10 seconds, a lean condition is indicated."
In older carb cars altitude causes a rich mixture, but the ECU should be compensating; I didn't see any black smoke behind, so I assume for now it was too lean.

Any thoughts?

I'll try to do it again this week with TunerPro saving data and see.
Edited by rjsdotorg, Mar 10 2013, 10:05 PM.
Offline Profile Quote Post Goto Top
 
rjsdotorg
Member Avatar
R E Member

Well, after seeing a few folks have done the fuel heat mod from the other thread, I suppose I can eliminate that as a concern.

Still, are there no other high altitude driver out there?
Offline Profile Quote Post Goto Top
 
Wolf
Member
[ *  *  * ]
I don't have any good ideas about what the problem may be, but I've taken Geos over 9000ft roads more than once without issues. The catalytic converter could have fused and be partially blocked- that can cause a dead power curve near wide-open throttle. The code 13 may be exactly what it says; your O2 sensor may have died. Sorry, but nothing else comes to mind :(
Offline Profile Quote Post Goto Top
 
rjsdotorg
Member Avatar
R E Member

Thanks Wolf, I did check that O2 code 13 did not reset, after another 1/2 hour of driving. It was not long WOT at 6000 though, only 5-10 seconds at WOT on occasion.
When I rebuilt ~1k ago I had the cat off, back flushed it with water, blew air through without resistance and had it Cal. smogged.
I do have the XFI grind cam and ~8 degree cam advance, but no reports from others that it causes any such issue.
Offline Profile Quote Post Goto Top
 
Rhinoman
Advanced Member
[ *  *  *  * ]
On the early models I don't think the baro reading updates while driving so it may be an idea to stop halfway up, switch off and restart to see what difference that makes. The 1996 on models usually update it based on max. and min readings from the MAP sensor.
As well as the AFR adjustment at some point the EGR should be disabled but if the baro hasn't updated then that won't happen.
Edited by Rhinoman, Feb 19 2013, 05:16 PM.
Offline Profile Quote Post Goto Top
 
Metroman1991
Member Avatar
Metroman1991
[ *  * ]
Just replaced the O2 sensor on my Geo Metro LSI 3 cylinder and exhaust donut type gasket from manifold and noticed a hell of a difference ! Cheap fix O2 censor was 17 bucks from Napa and a few dollars for the donut exhaust gasket ! Chaep fix before you get into all the other ( Might Be Issues )
Offline Profile Quote Post Goto Top
 
sphenicie


note to self: NTK o2 sensor, p/n 21002, pre95 metro, $17.95..........
Offline Profile Quote Post Goto Top
 
rjsdotorg
Member Avatar
R E Member

The baro reading thing is interesting. We'll see if the stop-change shows up in the data.

I'll keep O2 in mind when I look at the data. The one I have is ~1k miles old, and was showing good readings with Rhinoview last week.
Offline Profile Quote Post Goto Top
 
Rhinoman
Advanced Member
[ *  *  *  * ]
I had a look in the 95 FSM and it does state that the Baro updates at WOT, the 94 may do as well.
What do your fuel trims look like?
Edited by Rhinoman, Feb 20 2013, 05:55 PM.
Offline Profile Quote Post Goto Top
 
rjsdotorg
Member Avatar
R E Member

Rhinoman
Feb 20 2013, 05:54 PM
I had a look in the 95 FSM and it does state that the Baro updates at WOT, the 94 may do as well.
What do your fuel trims look like?
Which page of the FSM has the Baro info?

I did some screen caps with RhinoView; I think I now have TunerPro figured out, so I'll capture an XDL file later.
Sitting still, idled, and revved to 2500rpm in neutral.
O2 seems to fluctuate as it should with update set to 50ms.

idle - parameter page 1
Posted Image
idle - parameter page 2
Posted Image
2500rpm - parameter page 1
Posted Image
2500 - parameter page 2
Posted Image

Oddly, I've noticed some occasional serious power loss yesterday and today, and near sea level. Once climbing a hill in 2nd it almost died losing power; a few seconds later it came back.
Today, I was doing the runs with RV, and once at 2500rpm power just fell off and the engine died. It started right back up and ran OK! I was concerned that the TPS might have a bad spot, but the TPS position data showed smooth from 2deg at idle to 83deg at WOT, key on engine off.
I'm still concerned that the fuel heater is causing vapor lock or something - the inlet line is hot (not measured yet, but too hot to hold) with CTS at 202F.

I had a loose EGR vacuum hose yesterday that threw code 51 which I fixed: The hose wants to slip off the diaphragm bib easily - I need to clamp/glue that.
Edited by rjsdotorg, Feb 21 2013, 12:48 PM.
Offline Profile Quote Post Goto Top
 
Rhinoman
Advanced Member
[ *  *  *  * ]
A TP log would be good to look at. The TP definition works a little differently to RV, RV scans each of the addresses in turn, like a Tech1. When I wrote the TP definition I set it up to capture the faster moving data more often than the slower data. The TP data can also be replayed through the dashboard so you can replay it at various speeds and set up different graphs.
Offline Profile Quote Post Goto Top
 
rjsdotorg
Member Avatar
R E Member

I just got home and saved a TP log from Citgo stop to my exit ramp, climbing 2500 feet
http://rjs.org/cars/Metro/misc/warm%20up.xdl

In this cap (near the exit ramp ~7% grade, VSS is 11% low with new tires) I was in third and intentionally on/off the throttle 50% to capture the behavior. At WOT at this point the motor had a slight ping, so it was over-advanced (or lean?); I read where some ECUs drop out of closed loop at WOT and reduce mixture to 9.5/1, does the G10?
Posted Image
(BTW, can one change the scale? The O2 voltage and pulse width scales are way to big for the data values.)
You can see I'm on and off the gas, and RPM/speed barely changes.
I'm not sure how to interpret the short/long fuel trim S/LTFT numbers, and what then is TFT?

In this cap
Posted Image
I was at high cruise, then WOT when the road ramped up.
The TPS goes open, but O2, fuel trims and manifold pressure have not changed.

I also saved the log from the warm up, but it was done with the EGR diaphragm vacuum hose off (not intentional)
http://rjs.org/cars/Metro/misc/warm%20up.xdl
Offline Profile Quote Post Goto Top
 
rjsdotorg
Member Avatar
R E Member

Looking at my log, I noticed a few more things:
-The barometric pressure does not change.

- At around 14:00 I went from a gentle grade (where the O2 seems OK and is fluctuating) to 6%, and then the O2 went low when I let off the gas at 14:21 and was at .039 for a long time, with occasional .058 readings. Injector pulse width was always ~4.3ms even after O2 went low. I was climbing mostly at WOT in 4th. So nothing else changed at that point, fuel trims, manifold pressure, nada; the engine just went lean.

- I down-shifted to 3rd at 16:14 and O2 started fluctuating again, after IPW jumped to 6.3.

- Timing advance: around the 16:40 mark I was alternating TPS of 40°/WOT for ~5 seconds up/down; timing decreased at WOT from 31° to 29°. (And then, the second time I went WOT the O2 stuck at .058 again. )

This was a 6%-7% grade from 15:30 to 16:50.

I'm now suspecting an erratic fuel delivery issue, either clogged injector or weak pump. I can test static fuel pressure KOEO, and I'll look at the spray pattern again, maybe pull the injector, again...
Offline Profile Quote Post Goto Top
 
rjsdotorg
Member Avatar
R E Member

Well, just tested the fuel delivery.
25psi KOEO, .6gal/min free flow
I attached a hose to the pipe and jumpered the pink wires on the relay connector with KOEO, as suggested at
http://www.jeffsgeometro.com/geo-metro-fuel-pump-replacement--filter.html
(Be sure to release the gas cap first before pulling hoses.)
You have to pull the connector out the bottom of the fuse box. Probably could have just turned the key and measured how long the relay stayed on as well.
Posted Image

5 cups in 30 seconds. I was hoping the filter was plugged or pump shot.
Now I don't know what to test...

Could the O2, pump, or injector be intermittently poor?
Looking back at the TunerPro log, at 14:22 I was heading uphill in 4th, backed off the gas some, and the mixture went lean until I downshifted to 3rd. Nothing else changed in that time, injector pulse width, fuel trim, nothing...
Then the mix oscillated as normal, both sides of .45V, until the second time I pumped the throttle at 16:44.

Offline Profile Quote Post Goto Top
 
Rhinoman
Advanced Member
[ *  *  *  * ]
I'll have a look through the logs to se if I can spot something. One thing that I have noticed on the 95 is that the inj PW remains at its calculated value even when fuel cut is activated so when you are decelerating or otherwise on a closed throttle you will see the log go lean without PW changing.
Offline Profile Quote Post Goto Top
 
1 user reading this topic (1 Guest and 0 Anonymous)
Go to Next Page
« Previous Topic · Engine Tech & Diagnostics · Next Topic »
Add Reply