89 GTU having idle problem warm up from 3000rpm, drop normallly to 700, 15 mins later, A/C turn on the idle jumps around from 1100-500, bouncing like a basketball, when stop at the light, barke applied would even lower to 300 something

Luckily it never dies on road!

Then I wonder the following,
1. I never found my BAC valve on 89 GTU, not front, right.
where is the BAC of 89 GTU?

So I went A Famous shop in North Texas, paid $120 dollars for 10 mins, told me to paid 2500 to rebuild engine, because of low compression, ratio is 1st 6.7, 2nd 7.3, but it works fine except idle problem, I refuse the deal.

Is the ATF tricks work for a low compression engine?
Thx

 

Still COULD be a compression problem so don't rule it out. Yes it works fine, and they will even work GREAT, just before the bite it! Those figure do look bad, sorry! Then again, like most, it could run another 30k without a rebuild! Anyway, good luck to ya!!