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Timing being retarded
Posted: Fri Aug 11, 2006 3:14 pm
by Threshld1
So this has been an issue ive been having on and off for a long time now. I also believe it is directly related to my hessitation (hickups) that i get.
Yesterday i installed a new o2 sensor in hopes of curing my extra rich state. It helped but with no cats the sensor is still scanning its range at idle. I am getting a solid reading under load though.
Anyways im showing a 15 deg BTDC at idle and my timing light shows the same. I start giving it gas and it will go up to 50-55 with no load just fine. If im cruising on the highway with a constant speed i get a 40-45 deg btdc. Once i start loading the motor and going above 5psi of boost it will advance to 55 like it should but then start retarding. It does it in direct relation to my throttle increasing, and it will retard all the way back to 20 or less sometimes. Obviously it starts running like crap and missing with the timing that far off. The strange thing is im showing no correction from the knock sensor according to the scan tool.
Ive replaced my water temp sensor and last time i looked the knock sensor was a white connector. I also just replaced my timing belt pulleys as they were nearly shot and it helped the issue a lot but it is still present.
Anyone have any ideas?
Posted: Fri Aug 11, 2006 6:35 pm
by Legacy777
The O2 sensor is working correctly. It's supposed to scan back and forth at idle and light cruise. Only under acceleration or med-heavy load does it stay at a steady number.
I haven't watched the timing too closely, but have you checked/replaced your plugs & wires?
Posted: Fri Aug 11, 2006 7:17 pm
by Threshld1
Its scanning from .03v to .94v. Is this normal?
Just put in some V power 6 temp range gapped at .038 with magnecor wires. I am concerned about the fact that the new wires all have a resistance of ~15.3kohms. The service manual says 4-15k.
Posted: Fri Aug 11, 2006 7:20 pm
by Legacy777
That's what it's supposed to do
Posted: Fri Aug 11, 2006 7:40 pm
by quicklook
first , how the heck do you check timing at cruising highway speeds?
second, the computer constantly changes the timing for different conditions.
third, are you sure you installed the timing belt properly.
try using a vacuum gauge.
what codes do you get?
Posted: Fri Aug 11, 2006 8:22 pm
by Threshld1
Scantool shows live timing and correct and all that other good stuff.
Yes it should be changing but it shouldnt be going down to 20 or less as i approach WOT
Timing belt ive checked more than once to make sure i put it on right when i did my water pump. I marked it when i took it off and checked all 3 notches (not the arrows) after rotating the crank multiple cycles and it checks out all 12 o clock TDC. Timing light also confirms ~15 at idle and advance with more throttle. Im going to pull it again today and count the teeth according to the FSM just to be sure.
Vacuum gauge to check for leaks or what are you saying? Ive replaced more or less all the vac lines and am showing ~19.xx mmhg at idle
No trouble codes at all, ive put it in test mode and ran it also and still nothing. I had an o2 light coming on and off over the last month but that was because it wasnt hooked up.
Posted: Fri Aug 11, 2006 9:38 pm
by quicklook
a vacuum gauge tells a lot more about you engine than just leaks.
kind of old school but it tell if exhaust is clogged, head gasket bad, among other things.
a manual comes with them.
Posted: Sat Aug 12, 2006 7:08 am
by Legacy777
Agreed....engine vacuum is very valuable information.
I'd go drive mine with the select monitor to see what my timing is....but my damn car isn't running yet....and I'm in seattle.
Posted: Mon Aug 14, 2006 9:56 am
by bmxpunk
Have any of you tired "grounding type" mods. I did one like the usual engine block/starter/ strut towers. but I also ran one down to the 02 sensor. i fanned the wire out around it, then i held it to the 02 sensor with a hose clamp. granted i dont have a select monitor, the voltages that my perfect power was reading at the time smoothed out considerably and while it still scanned, it wasnt sush a huge deviation. My car idled and drove noticibly smoother. just a thought.
Posted: Tue Aug 15, 2006 6:39 pm
by Threshld1
Yeah ive upgraded my B- to block and chassis w/ 4 awg ontop of the stock wire. My o2 i got a 4 wire so i have a seperate ground wire instead of the exhaust.
Posted: Sat Aug 19, 2006 10:59 pm
by Josh Long
20 degrees of timing at full boost/ load is quite a bit of timing. I am not sure of the map values for this ECU but in turbo Mitsubishi stuff that would be not too shabby for a full pull. If it starts dropping down to in the area of 5 degrees you can really see the exhaust side of the turbo start glowing, as the combustion is being blown out the exhaust ports this is also seen with a marked rise in your EGT gauge.
You may want to start looking at some stand alone turbo maps and their high boost/ load timing values. To me it sounds like your ecu is working perfect.
Now if your car is NA that is something completely different.