Vintage Cars: 1978 280 SLC Auto, timing belts, compression issues


Question
QUESTION: Hi Ron: I've been experiencing a lag between putting my foot on the gas pedal and the power being delivered to the car. i have exeperienced a drop in power, lousier mileage.  Help!

ANSWER: first thought would be injectors , how recently have they been serviced.  Fuel filters/screens - how recent the service

Timing /dwell - how recent has this been done

I need a little more info to help - how many miles , service history, how long has the problem been going on?

---------- FOLLOW-UP ----------

QUESTION: Thanks for your reply Ron.  I recently replaced the fuel filters and the timing was adjusted whe i took on the car 2 years ago.  The problem has been there since when i got the car.  its a 78' and has 200,000 miles behind it.  The car has been serviced by guys from the dealership who started out thier own auto shop several years ago.  i replaced the timing belts and fluids, shocks, did some extensive body work, tuned the engine, replaced the airconditioner to a modern one, and there is no overheating anymore.

the power engaging when i hit the gas - there is a lag.  even when the gears downshift, its pretty clunky.  the gear changes being clunky is when the lag is most prominent.

Does this help?

Answer
that is a lot of miles for that engine,it is possible, depending on its service history to have some compression issues, and therefor a lack of power.  The 2.8 should not be expected to rocket that car!  If the timing has not been touched for 2 years, its time to do that again, and perhaps renew the poitns and dwell.  If the injectors have not been pop tested and renewed , that is a possibilty as well
If you pull a plug , what color is the tip.
How often do you drive this and how many miles since the last full tune up?
We have not even discussed possible transmission /vacuum issues as the problem. Do you get the same lag if you put the selector in low (1st) and accelerate?