Thanks for letting me join your forum!

I've got a 1987 suburban 5.7 TBI (engine is a 90) that you can be driving along fine then drops to about half power.

Now here's the weird part....
Wiggling the key in the switch (while driving) made it go full power than half again. Changed the switch...no help.

Moving the heater switch....same thing.

While rolling the electric back window, runs OK with switch depressed, let go, it goes to half power. Same thing.

Sometimes it idles fine and others pulsates.

Any Clues?

Thanks in adavance.

Scott
ScottND (at) hotmail (dot) com

check you alternator and battery and if they all check out ok then check you grounds

ScottND,
Did you ever figure out your problem?

ScottND,
Did you ever figure out your problem?

YES...I DID..it was a fuel injector. I got lucky enough to catch it during an idle with the air cleaner off and having someone run the windows. It just quit spraying!