I have an 88 testarossa euro and lately it has a lumpy idle, bounces from 500 to 14 hundred. Even when I touch the throttle to bring the rpm it still does it. Idles like a funnycar from the 70's. I tap the throttle and let my foot off and it stalls, once drive no problems. I can drive for an hour or more and sometimes it idles perfectly but most of the time it is lumpy. 113A. Problem is intermittant (Update) I bought a pair of vacuum gauges and did the work described as per the Testarossa manual. The engine is giving me a steady 14 inches of vacuum per bank, found a cracked hose off of the intake. I have been able to get the idle down to 1000rpm, anthing lower and it idles a little rough. I know I have to get an exhaust gas analyzer on it first to balance both sides out. It pull a lot stronger and black smoke from exhaust when I nail it has left. Any ideas on lowereing the idle rpm to 800? Before I take it in to a shop?
Don't see any reason to do this as the nominal TR spec is 1000 RPM warm idle. The F113A engine (K-Jet without Lambda) has almost no electrical components associated with the engine running, so initial troubleshooting becomes more a case of measuring the various CIS fuel pressures (control, supply, regulated supply) on both banks and seeing if any of those are misbehaving. Haven't had any prior reports here that I can recall for being "lumpy". If your symptom was that the idle sometimes is 500 RPM and sometimes is 1000+ RPM, I'd be suspicious that one of your fuel pumps is sometimes working and sometimes not (and it wouldn't hurt to confirm/deny if the contacts in the "y" white connector for the fuel pumps are toasted or not ), but, if it is repeatably changing from 500 to 1000+ every few seconds at warm idle, nothing obvious jumps out at me as what to do next -- sorry that I can't be more specific.
