I have been having an altercation with my car for over a month now. It starts easily, idles ok for minute or so, starts surging and missing, it doesn't die.
When I put in drive and start to accelerate it barely moves. If I open the throttle to a certain position it runs a little smoother but still not much power. Here is the fun part, if I
quickly switch the ignition off and on while still rolling. I get full power back and can go as fast as I dare. When I back off the throttle and the revs are around 2000 it lacks power again. I get no check engine light during all of this. Last night I ran my battery down trying to start it without gas in the tank . When I decided it might run better with gas in the tank, I added a few gallons and got a jump. When it started up I had the check engine light on, but it ran great. When I got home I checked for codes and it listed a 221 (oxygen sensor)
Here are the things I have done, replaced plugs,plug wires,distributor cap, rotor, oxygen sensor, fuel pump (the regina system only has one) fuel filter,air filter, timing belt. I checked the fuel pressure (43 psi with vac hose, 50 psi without) I installed a set of injectors from an 89 engine, no change in symptoms. The compression is right at 175lbs on all cylinders even after 270k. The vacuum reads 18 inches during the short time it is running smoothly at startup.
Has anyone got suggestions?javascript:add_smilie(":puzzled:")
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Thanks

you've done all the right things. your rough idling sounds like the idle control valve or something is going iffy. this would explain lack of power up until the engine is warm and runs without the need for extra fueling.

I would say it seems this because of your description of turning off and then back on with the ignition whilst running, which would imply that the cold start/idle system is a bit weird when it starts from cold.

I am not too sure about the regina system as i dont have it myself.

Matt

Did you check the catalytic converter to see if it collapsed and clogged? Leaking antifreeze into the exhaust will cause the CAT material inside to corrode and eventually collapse, causing the symptoms you mention.

Thanks for your responses, I found the problem ! I had replaced the oxygen sensor a month prior to this situation. I had been using the wrong type for 2 years ( the zircon type not the titania type. Thank you Autozone.) It was a Walker replacement sensor and it failed in a strange way, it was putting out a 5 volt signal instead of the .1 to 1.2 volt range. That was making the computer think the mixture was off the chart lean and it tried to send all the fuel it could. Walker replaced it under warranty.

I know this may be a little off topic but I feel it needs to be stated. I have quit purchasing what I call "mission critical" parts from Autozone and Advanced Auto because of the reliability and fit/form problems. They offer a warranty but what good is it when one is stuck on the side of the road? It won't cover towing bill or anything except for the part itself. I simply can't trust their stuff anymore.