| I just replaced my DW 550s with Nismo 740s from SZ (using DW adapters). I also put in new plugs at the time. I got everything together, tested for vacuum leaks, and loaded a stock map with a k-value of 160 and latency of 830. I started it up and with those numbers my afr is around 12 and I can hear plenty of misses! I dropped the k-value to 145 and it was still just 13.8-14 which tells me something is wrong. When I revved the engine it seemed fine. The generally accepted k-value is 160-165 and I would have to go ~135 for a 14.7 afr (which would still have misses). I did a power balance using Nistune and each cyclinder had the same effect. When just pulling coil pack connectors, 1-4 barely had an effect and 5 and 6 had a substantial effect. This has me confused. I assumed that I must have a pinched o-ring resulting in a leaky injector. Pulled the plenum, pressurized the fuel rail, used paper towels under all injectors, and I cannot find any leaks. I'm not sure what to check next so I wanted to ask before I throw the plenum back on. My symptoms tell me a leak, is it possible that there is only a leak when the injector is firing? There is definitely a problem though because it had a fairly normal idle with the DWs that just had an occasional miss and now it is a really rich idle with lots of misses. Compression was tested a week ago and is in spec so I should be able to get a smooth idle. Big thanks in advance.
'91 TT |
