99 GTXL not idling, backfiring

[andy.262]

you may have them backward,

well, THATS embarrassing..... when I hook it up the correct way it actually holds pressure like it should. I was able to get the pop-off set to within 1-2 psi of each other and held pressure for at least 2 minutes each. I will update tomorrow after work when I try to start it, don't want to upset the neighbors by trying to start it now (its almost 10pm here)

 

[andy.262]

Carbs back in the machine, pop-off is good, they definitely do not leak at this point. Sounds like it wants to start, but instead of starting it just backfires loudly through the exhaust still. Any other ideas of what to check?

It almost feels like a timing issue, since I know I'm getting spark on both plugs. Would a bad ground somewhere cause this? Where are the grounds that I need to be concerned about located?

 

[andy.262]

Apparently somehow I lost compression. Got the tester today and one cylinder was at 50psi and the other was at 120. I guess I found the issue