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- #41
screamin_conure
Active member
You've just spent money for a new set of injectors you may not have needed. I may have suggested this before but, if I did not...you need to stop guessing and get a copy of the Factory Service Manual and troubleshoot with that.
Keep in mind that with 160 on the right side long term fuel trim, the system is adding fuel...a lot of it. With 140 on the left, it's adding fuel, though not as much.
Gven the past symptoms, that new injectors, new IAC and a clean TB did nothing and current symptoms are lack of idle stability and high fuel trims, you need to get back to basics....look for a vacuum leak.
Hib,
Perhaps my last post wasn't worded very clear. The new injectors DID improve my BLM readings, at least on one side. With the old injectors, at idle, my right bank reading was 160. With the Bosch IIIs, my right bank is now 128. It is with the left bank that I'm now seeing BLM at 140, whereas it was around 130 with the original Multecs. In addition, with the new injectors I have noticeably more power and the car runs perfectly throughout the RPM range, with the exception of at idle. All that I was stating in my previous post is that while the Bosch IIIs have produced a noticeable improvement, they didn't solve every last little issue as I thought they might. So, I have more troubleshooting to do to make it perfect.
I DO own a factory service manual and I HAVE been using it extensively to troubleshoot this. The engine was tested with a smoke machine last fall by a mechanic whom I trust and no vacuum leaks were found. He and I both have gone over all of the various vacuum lines, big and small, and checked them for proper condition and secure connections. The engine holds a steady 15" inches of vacuum at idle. If this were a traditional vacuum leak problem, I don't think that I would be experiencing an idle that is right on the money when the car is started cold, for a period climbs to 150-200 RPMs over the desired idle that the ECM is calling for after the engine gets hot, and then returns to normal RPM several stoplights later.
So far, every "guess" that I've made has resulted in improved driveability. When I first purchased the car last fall, it idled at 1,100 RPM in gear. We tried first to clean the IAC and its passageway, but that offered little improvement. After replacing the IAC, idle improved dramatically. Based on the right bank 160 BLM that I had before replacing the Multecs, my "guess" that a fouled injector was creating a lean condition proved to be right on the money. Believe me, I'm not just going out and replacing parts willy-nilly just based on a hunch, and every part that I've replaced has come after a significant amount of testing and research before plunking down cash. For instance, one might expect my symptoms to possibly be originating from the fuel pressure regulator. However, I have tested that component per the procedure in the FSM and the results show that it is working fine. Therefore, I will not be replacing the FPR. I was also suspicious of the cannister purge solenoid. After following the FSM test procedure, it showed that it was working normally as well. The original part remains.
We are talking about a nearly 19 year old car that was known to have been equipped from the factory with certain componenents of questionable quality. In addition, the car itself received very little mechanical care from its previous owner. The replacement of various parts is going to be expected, wouldn't you think?
Respectfully,
Ron