Joe, My DeLorean has exactly the same starting problems that David's has. I suspect some sort of device has failed but I too am at a loss for "guessing" which one. My D has less than 10,000 on it and the engine has NEVER been worked on or tinkered with until only recently. The starting problem began years ago. I seriously doubt a wiring problem or a vacuum line problem. I have all the correct answers to the questions you posed to David. So, now it's beginning to sound like either the warm-up regulator or the frequency valve has failed. Although you state that neither has a high failure rate, which one do you think would be most likely to fail if that's the case? This is shotgunning, but perhaps I could change one and David could change the other one. If one or the other works, then we will know. If neither works......hmmmmmmm. Then what? BTW, how expensive are these two devices? And which one is easiest to replace? Could either or both be removed, disassembled, cleaned or repaired, and reinstalled? If so, would that be a reasonable alternative to replacement? If it works, it works. If not, we are back to square one, but nothing lost except for some time. What are the operational symptoms one might expect to encounter caused by the failure of each of these devices? If I had to describe the operational symptoms I'm experiencing, they would be identical to what David has written. I am beginning to get the distinct impression that the problem we are having is rare. Thanks for listening. Ed Thompson (#6419) Midlothian, VA DMC Joe wrote: > > David, > Close your wallet, no need spending that kind of money. > > Here are a couple of questions. > Are all vacuum lines properly connected ? > Has the CO mix ever been adjusted ? > Is the tamper proof plug still in place ? > Do you hear the frequency valve buzzing while the engine is idling ? > > BTW both the warm up regulator and frequency valve have an extremely low > failure rate, I seriously doubt that either one needs to be replaced. > ------------------------------------------------------------------------ eGroups.com home: http://www.egroups.com/group/dmcnews http://www.egroups.com - Simplifying group communications