Folks, I've got a 1990 760T that's just started running like crap. It runs well cold (New England kind of cold) and at idle hot or cold, but when it warms up it starts sputtering and choking and gasping and dropping cylinders under any kind of load. You stomp on it and it just chokes and shudders and tries to stall, back off on the gas and drive like a little old lady and it holds together pretty well. Fuel filter and air filter are new, vacuum lines are new, plugs and wires are relatively recent. Any ideas would be much appreciated.

If those pretty new plug wires are not Bougicords then they could be the problem. Wires w/ crimped ends don't make contact with the posts in the bottom of the distributor holes. This creates an extra gap the spark has to jump and weakens the plug spark. My turbo missed terribly when I jumped on the boost until I replaced my plug wires. Also like yours I could go easy and get as many rpms as I liked.

Have you checked the intake hoses for leaks on the underside? The oil lays up in them and causes the hose to soften from the inside bottom (usually). Run your hand under the intake hose at the manifold entry and see if it is wet or has a hole in it.

The problem could also be the ECT sensor under the third intake runner(good info in the 700/900 FAQs). When they fail the car either runs very rich or very lean when it warms up. It sounds like your air/fuel ratio is somehow getting screwed up after warmup.

Low fuel pressure at the rail could be a problem also. Check the pressure regulator function and check the fuel line pressure.

Regards,

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Will Dallas, www.willdallas.us, www.willdallas.org, www.willdallas.com, www.dallasprecision.com 86 245 DL 222K miles, 93 940 260K miles, 88 765 GLE 152K miles, 88 780 246K miles