My '82 240D has started to nail/ping at idle after the car is warm. It does it after I have driven at high speeds and when the car is at idle. It goes away after a while but it only happens during idle. I've run 2 cans of diesel purge which helped but it still has a definite nailing after a high speed run.

Anyway, I want to get the injectors looked at by taking them to a diesel shop. Does anybody have any recommendations in the Houston area where I can take the injectors to be tested/cleaned?

Thanks