The Chrysler K-Car Club

I'm running out of ideas and could use some help! My 1988 Reliant Wagon, 2.5L, AT, 140,000 miles has had some driveability issues which I've mostly solved. It only has two problems right now, which are probably related. At steady throttle at highway speed (60-65 mph) the engine will seem to have a slight power loss for a few seconds, then regain the power for a few seconds and then repeat constantly. It is a very regular cycle of about 3-4 seconds in each phase of low power and normal.The power loss is minor and does not feel like a miss or fuel interruption, but is noticeable enough that it is very annoying. The second issue is higher than usual fuel consumption. In the last few months I've replaced plugs, rotor and cap, plug wires, coolant sensor,PCV valve, fuel injector, IAC motor, air filter, most of the vacuum lines, and radiator cap. Compression is 120-125 on all cylinders. I've cleaned the EGR valve and it seems to be OK. I don't want to keep throwing parts at it. Any ideas? All input is appreciated!

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Thanks for the response. Yes, I originally had a code 25 indicating an IAC problem. That's why I replaced the IAC unit, which solved some drivability issues. When I submitted my post I had just cleared the codes and did a test drive and that's when the pulsing seemed to be the only remaining issue. I had only driven the car briefly at that point, not enough to set codes. I have since checked the codes again and I'm getting code 12 and code 21, which I had not gotten before. The car starts fouling plugs within 50 miles. I guess fixing one thing can cause the computer to see something else. I've ordered an oxygen sensor and should be able to put it in this week-end. I'll post the results, but it will be a few days to a week.

Success! My wife and I finally have driven the car enough that I can confidently say all symptoms are gone after replacing the oxygen sensor. There are no codes showing, either. I owe a lot to info I found on this site, and I'm sure I saved a lot of money by doing the analysis with help from this site and doing the repairs myself.

Very glad to hear it. Price of admission, could you please email me some pictures of your classic wagon at aries89@chryslerkcar.com?