Eddy,<P>Give me another week to battle this headache. A known functional carb is certainly interesting...<BR>The dist advance spring is another one I'll look at. I want to re-check the secondary vacuum levels again too, I'm thinking that the secondarymay not be operating at the slight vacuum required.<P>Further details...<BR>Refilled with highest octane rating, instead of mid-level. Now the chatter/ping/etc that would start before the onset of the "sticking valve" power loss is noticably reduced, though the back-fire afterwards is still there. WithOUT any carb cleaner added to the gas, the power loss hit hard this morning. Is it dirt after all? <BR>Talked with the mechanic by phone, and described all of the above writings from the past week. He seems to favour something electrical, possibly temp sensor. <BR>TPS problem would apparently always act at the same throttle POSITION, rather than any specific RPM. My problem is unrelated to throttle position, and occurs when trying to accel under load in higher gears, especially after a few minutes of cruising at the same speed.<BR>Checked the temp sensor with the volt meter this PM, and the resistances seem ok at hot and warm. Still need to check cool and cold. Then (as per other thread) noticed I may have a problem with the thermoswitch (the vertical one in the intake manifold), with both the wire looking bamaged, and the top of the switch looks corroded. I measured the resistance with the volt meter from the switch center post to ground, and saw no resistance. Then checked it again a few minutes later, and the resistance was infinite... Can this variable reading give me the variable apparent carb problem?<BR>I then added a bottle of STP carb cleaner to the new tank of gas, and went for another hiway run. Behaves better WITH the carb cleaner... But also noticed it wouldn't shift into OD for about 5 seconds on one test. This is getting stranger.<BR>For the most part the engine runs very well, and very smooth right up to 5,000 RPM. But still gives me problems under load, about 50% of the time.<P>More checking...<P>Thanks all,<P>Don<P><BR>(having a terrible time posting since yesterday...)
