| Author | Message | ||
     Ratchet |
Ever since I have owned my 2000 S3, one year, it has run rough below 3,000 rpm. At 3k and above it smoothes out and runs great. The bike has a Race ECM. I have zero history of the bike. Plugs are brand new. | ||
| Firemanjim |
Mileage on bike-- have the intake seals ever been changed?? Get yourself a copy of ECM-Spy so you can look and see how bike is running. | ||
| Hootowl |
It will always run rough below 3k rpm because of the cams. Keep it above that. | ||
| Ratchet |
The mileage is 5100. Not sure about intake seals. Do you have a part number for the intake seals? | ||
| Firemanjim |
HD uses same ones on Sportsters since EVO motor came out. Spray Brakleen or carb cleaner at manifold to head junction while engine running and see if idle changes. | ||
| Stevebee |
hey all, same horrible issue with my 99 - s3 plus the fact that the front cyl. is running very rich and the rear cyl. plug looks perfect. listing of whats been checked : * no error codes according to the engine dash lite / also ck'd by HD tech with scanalyzer, no error codes and afv 100%, tps approximately 0.5v - 1.2v. * no intake gasket leaks * injector leak test with engine not running * new ets * new plugs and wires * new 93 octane fuel and fuel filter next items to be changed (it's only money) will be the O2 sensor (test ride)then follow up with a new coil. without changing the exhaust manifold gaskets,(sucking in fresh air confusing the O2 sensor) i know of no test for that... comments: the O2 sens. communicates with the ecm at approx. 2500 rpm and 800F, the engine performance drops off between 2400 / 3000... fouling the front plug. thus, maybe O2 sens.? next, has anyone heard of a coil failing on one cyl. at low rpm ? this problem is becoming very pricey, frustrating, and dangerous. twisty country roads or in the city this loss of power gets a bit hairy. i'm struggling to come up with new test procedures. Any feedback will be appreciated and followed up on. lastly, what will the spyware do for me if in fact,the(race)ecm reverts to it's original factory mapping functions after 50 thirty second start / stop sequences ? | ||
| Stevebee |
hey guy's, follow up from my last posting. will someone post the aftermarket O2 sensor manufacturer name and part number ? hate having to go to HD..... thanks | ||
| Ebutch |
Bosch 12014  | ||
| Akbuell |
To Stevebee: Since you know what has not worked, time for a rethink of the issue. First, do a compression check. The actual numbers are not as important as the 2 cyls being within about 10% of each other. Eliminates bad rings/valves/ect. Since the AFV is in the 100 area, things like leaking intake seals can be eliminated. The ECM is not having to compensate for out of spec readings by skewing the entire fuel map. Also means the O2 sensor is probably OK. So a very rich indication for the front cyl can be caused by a Lot Of Fuel, or Really Poor Spark. I would re-check the front injector. Or replace it, or swap it with the rear injector and see if the problem follows. I have seen situations where a quick 'garage' check of an injector did not reveal that it was actually clogged or leaking. Carefully checking the coil with a ohm meter, following the procedures in the service manual, should be enough to be able to rule the coil out. Hope this helps, Dave | ||
| Stevebee |
thanks guys i will follow up and post am i stuck with buying injectors from HD or are there other replacements ? | ||
| Akbuell |
Check around the area for a speed shop or auto place that can calibrate/check/rebuild injectors, and see if yours are within spec. They also should be able to tell what other suppliers will cross over, if that becomes necessary. |
