77 Wont make power

[Guest Dans 77 Limited]

My 77 Electra has the 403 "corporate motor".Last year I changed the fuel filter for the 1st time, since I have owned it. At that time I discovered the cars original owner had wrapped teflon tape around the fitting where the filter goes into the carb. Some of that Teflon tape got into my fuel system and really screwed things up. I dont know if that has any bearing on where Im at now, but just to cover every base I threw this info in also.

My current problem is the car just wont make any power. If you hit passing gear at highway speeds its like throwing a boat anchor out the window. The motor sounds steady but the car slows down and starts surging. Coming home from Roy Schafers funeral last Saturday I could barely get up the hill by my house. I have had the following items checked by professionals.

*Transmission-OK

*Exhaust system including catalytic converter-No blockages.

I have replaced with original GM parts the following list.

Had original carb rebuilt

Replaced original carb with new Quadrajet- big$$$$$$

On my 3rd new fuel filter in less than a year

Have removed the belt to the A/C- thought maybe compressor was locking up or dragging

Replaced fuel pump

Replaced distributor cap

Replaced coil

Gapped & replaced plugs

Replaced wires

Replaced rotor

Replaced the electronic module under the rotor in the distributor

Replaced air filter

Replaced PCV valve

Replaced EGR valve

The car starts right up and idles glass smooth. There is no rhyme or reason to this . But it does seem to occur more often after the engine has been running for a while. But it also happens occasionally when the engine is cool.

I dont know what else to try , if you have any ideas please let me know.

Thanks

Dan

[Guest sixpack2639]

Detent cable out of adjustment? Could be not down shifting completely. Does it hesitate at all starting out? Hesitation could also show up when trying to shift into passing gear. Could be bad accelerator pump. (I have gotten brand new ones that were bad). When was the tranny serviced last? Could be clogged filter not allowing enough fluid flow. Hope that helps. Carl

[JohnD1956]

Have you inspected the vacuum hoses? I'd replace them all and try that before going any further. But then I'd start looking at the timing chain slack.

JohnD

[ted m]

I would look at the rubber fuel line hoses over the rear axle,coming from the fuel tank. After almost 30 years,they may be dry rotted . Ted