View Full Version : '89 stumbling at 5# boost solved!

09-05-2008, 09:07 PM
I've been fighting a stumble or bog in my '89 at about 5 pounds of boost. It started after the check engine light came on and code was oxygen sensor. Replaced the sensor and the bog started. Put the old sensor back in and the bog went away for a short while then came back. Did lots of research on this forum (great!) and posted a couple of threads (thanks for the inputs). Went through all the normal things to fix (wires, plugs, fuel filter) and found no change. Finally broke down and bought a fuel pressure guage, taped it to the windshield, and found the bog came with a drop in fuel pressure!

Lucky to have Ryan (Thunderbird SC Shop) local, he had a fuel pump/sender out of a low mileage car, drove up on Labor Day and bought it, got it installed, and problem gone!

Car is running great, but the bloody CEL still comes on from time to time and throws a code 41 (oxygen sensor) - usually after a long cruise at speed when I slow down. But I'm not going to sweat it, she's running way too good.

Moral of the story is sometimes its best to break down and spend the $40 for diagnostics before spending hours of labor and a hundred bucks on parts that don't hurt, probably help performance, but didn't solve the problem! And sometimes things that seem coincidental (like changing the O2 sensor and the bog) are just that - coincidental.

I've had my '89 since 1992 and she's gone from my daily driver to years of sitting around to a member of my collection of classics. And thanks to the knowlege in this forum I've corrected 20 years of small problems and got her back to brand new.

Thanks to all that offered ideas, special thanks to Ryan.

09-05-2008, 09:12 PM
Ryan is a good guy, i have bought many a parts from him, best guy in MN for sure to find sc parts.