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Hey everyone, i have been having problems with my car lately, it seems to be getting slower and slower and it is eating gas more than it ever did before. The gas issue could maybe be partially attributed to the changeover from winter to summer gas at the pumps, but i highly doubt it. Anyway, the only thing that really caught my attention while using the scan tool was that my ignition timing under high boost seems to go to 0 deg. BTDC or even lower for a few "frames" (times that the scan tool retrieves the readings from the ECU), then it goes back up a little. The last time i ran the tool I could have sworn that it wouldn't go below 15 BTDC. I reset the ECU this morning and the problem somewhat went away for a few hours, but then it was back. I know at least today it wasn't due to the weather as it was barely 70 with low humidity. I have been running 93 octane gas in it for the last month or so, and 92 before that. I will try 94, but i dont think it makes much of a difference. Has anyone else noted their ignition timing with the scan tool? I'd like to know what other people are seeing under boost. Also, if anyone has any ideas as to why my car is doing these things, please post your thoughts.

NemesisEJ22t wrote:Hey everyone, i have been having problems with my car lately, it seems to be getting slower and slower and it is eating gas more than it ever did before.

That sounds like it could be that your O2 sensor is gettin' funky. I can't add anything on the timing issue but what are your fuel trims and O2 sensor readings?

Woah. 0 degrees?! Can you even produce enough power to accelerate the engine with such a late spark?

It stays steadily at 0 degrees?

To add to what Matt asks, also, what are your timing correction values like?

The last time i looked at it, the timing correction value didn't deviate more than 2 from 0. The ignition timing wasn't steady at 0 deg. but it's not like it was just an error in the ECU or the tool. I could feel the power drop off and then come back on slightly. I'm gonna go hook it up right now and see what it gives me. Fuel trim is weird sometimes, it is usually 0 at idle and WOT, the only time i noticed something was at part (15-25%) throttle where the fuel trim will jump all over the place. The scan tool is giving me some decent values for the O2 sensor i think, but i'll check it again. I'll post up the results shortly.

incidently O2 sensors often test ok even if they're faulty, you have to check the values and see how quickly they change with throttle position.

I just thought of another thing --

The ECU sometimes stops sending values to the scantool. It seems like it happens mostly at high RPM; I haven't determined yet whether load has anything to do with it. In fact, it might all just be EMI, though the Select Monitor also fails to read under those conditions.

I should make the scantool tell you how stale the information it's showing you is somehow... I'll try to do that sometime soon.

Ok, sorry for such a long delay, i forgot all about it because i put the car back to stock boost due to gas consumption and to try to save whats left of the clutch. Anyway, the reading would go as low as 9 deg. at WOT, then increase to 13-14. That still seems a little low to me, but i could be wrong. About the scantool, i've only noticed it stop sending values (until it's restarted) when the cruise control is engaged. This only happens sometimes, and if you restart the comp. it will come back even if the CC is still engaged. It's just a little difficult to use DOS while on the highway, lol.

You don't need to restart the scantool to make it reinitialize its connection to the ECU; you just have to press Enter. (Actually, you can press any key other than the space bar, Backspace, and Escape.)

I was trying that, but what it was doing was different. It was acting like the car was turned off, there were no values showing up, and pressing enter wouldn't change it.

Huh. Weird. Are other people having the same difficulty?