Post 30K tune-up problems

[glenndeweirdt]

Just completed 30K service on my '83 911 SC w/28K miles. Car was running great except for annoying warm start difficulties so I decided to replace fuel accumulator and do 30K service. Adjusted valves, replaced air filter, fuel filter, distributor cap, rotor, plugs (did not check gap before installing), changed oil and filter, but did not replace oxygen sensor (trying to figure out a way to avoid purchasing slotted socket). Now the car idles a little slower but has very little power on acceleration. does not want to rev. Also backfires when accelerator is pushed. Also the muffler seems EXTREMELY hot but temp guage not above normal. Could I have screwed up the timing, adjusted the valves too tight, screwed up mixture (or all of the above?) Could incorrectly gapped plugs cause this problem? Should I just take it to a real mechanic with hat in hand and subject myself to humiliation and ridicule? Help

[Bill Douglas]

Oh don't bother to pay for humiliation and ridicule, we'll do it for free.

My guess is the distributor cap and/or rotor is the wrong part. How about swapping the old one back in just to test it as this is an easy test.

[dean]

I would say check the plug wiring. I would also check the CO. I am not sure but if your fuel filter was really plugged then you changed it, it might change the mixture. The backfiireing could be a lean mixture or retarded timing or the plug wires crossed

[toolman]

You can remove the O2 sensor by using a box end wrench, just cut the wire off at the sensor after all your going to replace it anyway. Don't spend the money for a OEM unit either, all O2 sensors are the same except for how many wires they have. I think yours has 3 wires so just get a universal fit from any auto parts store and wire the plug onto the end and put some shrink tube on the connections. Standard 3 wire sensor is about $40.

[glenndeweirdt]

Ok grabbed the old cap and rotor out of the garbage-good thing pickup is tomorrow! I'll try swapping back. Any easy way to check for crossed plug wires? I assume the pattern onthe distributor cap should be the firing order 1-6-etc. in a counterclockwise pattern statring at the TDC timing mark? I wonder if the dist might have moved slightly causing a timing change? Thanks

[glenndeweirdt]

Yep, bought the standard o2 sensor on Ebay for $29 bucks.
mine is an '83 so it's a single wire.

[Doug Zielke]

Do you have a timing light?
I think the timing is w-a-y out of spec.