It's not a good idea. I used to do that back in the early eighties until I started to notice how "coked up" the heat shields were getting on some cars. If you have an injector problem, it's just time to have them tested.
Regards,
Randy D.

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W.R.Durrance
ASE Master Tech
Mercedes Tech 21 Years
68 250SE
68 SAAB 96 Ice Racer
69 300SEL 6.3
70 300SEL 3.5
81 300TDT
W.R.Durrance Engineering