You said: "....I don't think my Frequency Valve is not functioning...I don't hear it buzzing while the engine is idling or when I rev the engine up...could this be what's causing my backfiring problem?" The engine will not provide satisfactory performance throughout its entire range if the frequency valve (acceleration enrichment circuit) is not functioning. DMC Joe www.dmc.tv "We're here to help you" DMC Help / De Lorean Services / <dmchelp@xxxx> ----- Original Message ----- From: srubano@xxxx To: dmcnews@xxxxxxxxxxxxxxx Sent: Tuesday, July 24, 2001 11:12 PM Subject: [DML] Back on track! Anyway here's the deal: I can start my engine with no problems but it does have a slight back firing problem in the high RPM's. I know it can be anything causing it but here's what's happening....I don't think my Frequency Valve is not functioning...I don't hear it buzzing while the engine is idling or when I rev the engine up...could this be what's causing my backfiring problem? Also...when I connect a DWELL meter to the diagnostic plug (to the same circuit that's for the Frequency Valve) I don't get any readings (as one website describes and a few Bosch K-Jet repair manuals say)...could I have a faulty computer?? Also another strange thing...I let my engine idle for a few minutes today....when I went to turn the ignition off the engine was still running after I turned the key to the off position and removed the key. I thought maybe there was something wrong with the ignition switch so I unplugged it....engine was still running. I next removed the RPM relay knowing that it would stop the fuel pump and kill the engine...that stopped the engine. This was the first time this had ever happened. Thanks, Steve [Non-text portions of this message have been removed]